Draft Rev # 7 Dated 6-14-2013

P u b l i c I n t e r e s t E n e r g y R e s e a r c h ( P I E R ) P r o g r a m

DRAFT F I N A L P R O J E C T R E P O R T

CALHEAT RESEARCH AND MARKET 

TRANSFORMATION ROADMAP FOR 

MEDIUM- AND HEAVY-DUTY 

TRUCKS 

FEBRUARY 2013

CE C-XXX-XXXX-XXX

Prepared for: California Energy Commission

Prepared by: California Hybrid, Efficient and Advanced Truck Research Center
Draft Publication Rev # 7 Dated 6-14-2013

Prepared by:

Primary Author(s):

 Fred Silver, Vice President

 Tom Brotherton, Regional Director

CalHEAT Truck Research Center/CALSTART 

48 Chester Avenue, 

Pasadena, CA 91106

626/744-5600

www.calstart.org and www.calheat.org

Contract Number: 500-09-019

Prepared for:

California Energy Commission

Reynaldo Gonzalez

Contract Manager

Reynaldo Gonzalez

Project Manager

Linda Spiegel

Office Manager

Energy Generation Research Office

Laurie ten Hope

Deputy Director

Energy Research and Development Division

Robert P. Ogelsby

Executive Director

DISCLAIMER

This report was prepared as the result of work sponsored by the California Energy Commission. It 

does not necessarily represent the views of the Energy Commission, its employees or the State of 

California. The Energy Commission, the State of California, its employees, contractors and 

subcontractors make no warrant, express or implied, and assume no legal liability for the information 

in this report; nor does any party represent that the uses of this information will not infringe upon 

privately owned rights. This report has not been approved or disapproved by the California Energy 

Commission nor has the California Energy Commission passed upon the accuracy or adequacy of 

the information in this report.
Draft Publication Rev # 7 Dated 6-14-2013

i

ACKNOWLEDGMENTS

The staff of California Hybrid, Efficient and Advanced Truck Research Center (CalHEAT) and 

CALSTART would like to express their appreciation to the CalHEAT Advisory Council, 

Steering Committee, and Technical Advisory Group (shown on the following two pages); to the 

California Energy Commission; and all others who have participated in the development of this 

Roadmap as part of an effort to reduce medium- and heavy-duty truck emissions and 

petroleum use in California to help meet or exceed the mandated environmental policies 

established through 2050. 
Draft Publication Rev # 7 Dated 6-14-2013

ii

ADVISORY COUNCIL AND STEERING COMMITTEE MEMBERS

Reynaldo Gonzalez, Program Engineer Public Interest Energy Research, CEC; and Co-Chair Advisory 

Council

Fred Silver, Vice President, CALSTART; Director of CalHEAT; and Co-Chair Advisory Council

Jasna Tomic, Program Manager, CALSTART; and Chairperson Steering Committee

Other Members:

Jack Broadbent, Executive Officer, Bay Area Air Quality Management District

Connie Burek, Solutions Specialist, Heavy Equipment & Truck-IBM Global Business Services

Joe Calavita, HVIP Program Manager, California Air Resources Board 

Rick Cameron, Director of Environmental Planning, Port of Long Beach 

Kerry Cartwright, Director Goods Movement, Port of Los Angeles

Mark Duvall, Manager, Technology Development, Electric Power Research Institute

Doug Failing, Executive Director Highway Programs, Los Angeles County MTA

Jack Kitowski, Chief Freight Transportation Branch, California Air Resources Board 

Ben Machol, Manager Clean Energy & Climate Change Office, US Environ. Protection Agency, Region 9

Matt Miyasato, Assistant Executive Deputy Officer, South Coast Air Quality Management District 

Felix Oduyemi, Senior Program Manager, Smart Grid Policy & Planning, Southern California Edison

Terry Penney, Laboratory Program Manager — Vehicle Technologies, National Renewable Energy 

Laboratories

Jeffrey Reed, Director of Emerging Technologies, SoCal Gas

Michael Roeth, Executive Director-North American Council for Freight Efficiency 

Seyed Sedriden, Air Pollution Control Officer, San Joaquin Air Pollution Control District

Rose Siengsubcharti Environmental Specialist Associate, Port of Long Beach

Paul Skalny, Managing Director and CTO - Venture Management Services

Ben Sharpe, International Council on Clean Transportation

Doyle Sumrall, Senior Director of Business Development, National Truck Equipment Association

Erik White, Assistant Division Chief, California Air Resources Board, Mobile Source Control Division
Draft Publication Rev # 7 Dated 6-14-2013

iii

CALHEAT TECHNICAL ADVISORY GROUP

Dan Bowermaster, Senior Project Manager, Electric Transportation, Electric Power Research Institute

Michael Britt, Director, Maintenance & Engineering International Operations, United Parcel Service

David Bryant, Vocational Sales Manager, Daimler Trucks North America

Tim Carmichael, President, California Natural Gas Vehicle Coalition

Dennis DePazza, Senior Manager, Terex Utilities

Mihai Dorobantu, Director, Vehicle Technologies and Innovation, Eaton Corporation

John Duffy, Senior Project Engineer, Kenworth Truck Company

Michele Duhadway, Marketing Specialist, Bosch Rexroth Corporation

Vincent Duray, Product Planning Manager – Hydraulic Hybrids, Eaton Corporation

Gordon Excel, Vice President and General Manager, Americas, Cummins Westport

Joe Gold, Director, Fleet Engineering, Frito-Lay North America, Inc.

Abas Goodarzi, President, US Hybrid Corporation

Darren Gosbee, Engineering Director, Transmission, Integration and Hybrid Powertrain, Navistar Inc.

Mark Greer, Green Fleet Market Manager, Altec Industries, Inc.

Anthony Greszler, Vice President Government and Industry Relations, Volvo Powertrain North America

Jan Hellaker, Vice President, Volvo Group

Mark Howerton, Manager, Strategic Marketing and Product Strategy, Allison Transmission Inc.

John Kargul, Director of Technology Transfer, U.S. Environmental Protection Agency 

Jim Kesseli, President, Brayton Energy

Jon Koszewnik, Chief Technical Officer, Achates Power Inc.

John LaGrandeur, Director of Automotive Programs, Gentherm Incorporated

John Lapetz, Vice President, Westport Light Duty NA

Jim Mancuso, Vice President, Current Product Engineering, Azure Dynamics Corporation

David Mazaika, Executive Director Strategic Development, Quantum Technologies World Wide

Mike Mekhiche, Director, Products and Technology, BAE Systems

Patric Ouellette, Chief Scientist, Westport Innovations Inc.

Terry Penney, Principal Laboratory Program Manager, National Renewable Energy Laboratory (NREL)

Jeff Reed, Director, Emerging Technology, Sempra Energy

Philip Schnell, Engineering Program Manager, AVL Powertrain Engineering, Inc.

Mike Simon, President and CEO, Transpower

Rudy Smaling, Executive Director – Systems Engineering, Cummins Inc.

Jordan Smith, Manager, Electric Drive Systems, Southern California Edison Company

Mike Stark, Senior Technical Sales Manager, Freightliner Custom Chassis Corporation

Doyle Sumrall, Senior Director Business Development, National Truck Equipment Associations (NTEA)

Joe Vollmer, Director of Government Affairs, Sturman Industries

Alan Welch, Director, Engineering Development, Westport Innovations Inc.

Marc Wiseman, Principal, Ricardo Inc.
Draft Publication Rev # 7 Dated 6-14-2013

iv

PREFACE

The California Energy Commission Public Interest Energy Research (PIER) Program supports 

public interest energy research and development that will help improve the quality of life in 

California by bringing environmentally safe, affordable, and reliable energy services and 

products to the marketplace.

The PIER Program conducts public interest research, development, and demonstration (RD&D) 

projects to benefit California.

The PIER Program strives to conduct the most promising public interest energy research by 

partnering with RD&D entities, including individuals, businesses, utilities, and public or 

private research institutions.

PIER funding efforts are focused on the following RD&D program areas:

 Buildings End-Use Energy Efficiency

 Energy Innovations Small Grants

 Energy-Related Environmental Research

 Energy Systems Integration

 Environmentally Preferred Advanced Generation

 Industrial/Agricultural/Water End-Use Energy Efficiency

 Renewable Energy Technologies

 Transportation

Research and Market Transformation Roadmap for Medium- and Heavy-Duty Trucks is the final report 

for the CalHEAT Project, Phases 1 through 3 (contract number 500-09-019), conducted by 

CALSTART. The information from this project contributes to PIER’s Transportation Program.

The California Hybrid, Efficient and Advanced Truck Research Center (CalHEAT) was 

established by the California Energy Commission in 2010 as a project operated by CALSTART 

to research, plan, support commercialization and demonstrate truck technologies that will help 

California meet environmental policies mandated through 2050.

The Roadmap describes the objective, approach, results and conclusions of the work done from 

2010 through 2012 to identify near-term action items for the period from 2013 through 2020 to 

reduce petroleum use and greenhouse gas and particulate emissions from medium- and heavyduty trucks.

For more information about the PIER Program, please visit the Energy Commission’s website at 

www.energy.ca.gov/research/ or contact the Energy Commission at 916-654-4878.
Draft Publication Rev # 7 Dated 6-14-2013

v

ABSTRACT

The California Hybrid, Efficient and Advanced Truck Research Center (CalHEAT) was 

established by the California Energy Commission in 2010. It is operated by CALSTART to

perform research into planning, commercializing, and demonstrating truck technologies for 

more fuel-efficient medium- and heavy-duty vehicles and to reduce emissions. The role of the 

research center is to coordinate the development of a Research and Market Transformation 

Roadmap to deliver clear actionable steps to help meet or exceed the 2020 goals for California in 

petroleum reduction, carbon reduction, and air quality standards, and identify longer term 

goals through 2050. Medium- and heavy-duty trucks account for 9% of greenhouse gases in 

California, and approximately 20% of fuel consumption. Improvements in efficiency or 

reduction of petroleum use by trucks provide a substantial opportunity to reduce emissions.

CalHEAT has identified 66 action items in the Roadmap, grouped under Electrification and

Engine & Driveline efficiencies, to help mitigate emissions or improve efficiency. Clearly 

defined, achievable “stepping stones” provide a pathway through successive stages of 

technology development and adoption across multiple technology categories and vehicle 

platforms. CalHEAT has collaborated in the development of this Roadmap with the State’s Air 

Resources Board, Energy Commission, Air Quality Management Districts, the U.S. Department 

of Energy, U.S. Environmental Protection Agency, and nationally-recognized medium- and 

heavy-duty truck associations, manufacturers, and experts. By 2050, implementation of 

advanced truck technologies through Roadmap action items could result in a reduction of more 

than 40 Million Metric Tons of carbon dioxide equivalent emissions compared to existing 

technology, referred to as “Business as Usual”. NOx is projected to drop from 249,000 metric 

tons/year in 2012 to 67,000 metric tons/year by 2050. Assuming an adoption rate for biofuels of 

25%, petroleum consumption by trucks decreases from 3.5 billion gallons per year in 2012 to 1.5 

billion gallons per year by 2050.

Keywords: Air quality, California Energy Commission, CalHEAT, goods movement, 

greenhouse gas emissions, low-emission trucks, medium- and heavy-duty trucks

Please use the following citation for this report:

Silver, Fred, and Brotherton, Tom. (CalHEAT). Research and Market Transformation Roadmap 

to 2020 for Medium- and Heavy-Duty Trucks. California Energy Commission. 

Publication number: CEC-XXX-2013-XXX.
Draft Publication Rev # 7 Dated 6-14-2013

vi

TABLE OF CONTENTS

ACKNOWLEDGMENTS .........................................................................................................................i

ADVISORY COUNCIL AND STEERING COMMITTEE MEMBERS ......................................... ii

CALHEAT TECHNICAL ADVISORY GROUP................................................................................iii

PREFACE.................................................................................................................................................. iv

ABSTRACT................................................................................................................................................v

TABLE OF FIGURES...............................................................................................................................ix

LIST OF TABLES .....................................................................................................................................xi

EXECUTIVE SUMMARY........................................................................................................................1

Introduction..............................................................................................................................................1

Regulatory Context and Purpose.........................................................................................................1

CalHEAT Truck Classification and Baseline Report.........................................................................2

CalHEAT Technology Roadmap Summary and Recommendations .............................................2

CHAPTER 1: Introduction and Summary ............................................................................................3

California Policy Context.......................................................................................................................3

AB 32 – The California Global Warming Solutions Act ...............................................................3

Other California Regulations............................................................................................................5

Federal Regulations ...........................................................................................................................6

CEC Guidance: What is the Roadmap? ..............................................................................................7

CalHEAT Roadmap Goals ................................................................................................................8

State of the Industry by CalHEAT Classification ..............................................................................9

Truck Fuel Use..................................................................................................................................13

Technology Roadmap Summary Results .........................................................................................14

Technology Strategies......................................................................................................................15

Investment.........................................................................................................................................15

Results................................................................................................................................................19

Technology Adoption......................................................................................................................26
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vii

CHAPTER 2: Technology Solutions and Action Roadmaps...........................................................29

Introduction to the Roadmap.............................................................................................................29

Hybrid Electric .....................................................................................................................................33

Electrified Auxiliaries..........................................................................................................................35

E-Trucks.................................................................................................................................................37

Electrified Power Take-off..................................................................................................................39

Plug-in Hybrids....................................................................................................................................41

Electrified Corridor..............................................................................................................................43

Alternative Fuel Hybrids ....................................................................................................................45

Hydraulic Hybrids...............................................................................................................................47

Optimized Alternative Fuel Engines.................................................................................................49

Waste Heat Recovery...........................................................................................................................51

Engine Optimization ...........................................................................................................................54

Alternative Power Plants and Combustion Cycles .........................................................................56

Transmission/Driveline Improvements ............................................................................................58

CHAPTER 3: Conclusions .....................................................................................................................60

Priority Actions ....................................................................................................................................62

Recommendations for Next Steps......................................................................................................63

APPENDIX A: Methodology and Sources..........................................................................................65

Resources...............................................................................................................................................65

California Truck Inventory and Impact Study ................................................................................65

Vehicle Technologies ...........................................................................................................................66

Vehicle Technology Pathways .......................................................................................................66

Gap Analysis.....................................................................................................................................66

Petroleum, CO2e, and NOx Reduction Analysis .........................................................................66

Adoption Analysis ...........................................................................................................................67

APPENDIX B: Sixty-six Actions by Technology Strategy...............................................................68

APPENDIX C: Sixty-six Actions by Timeline and Action Category.............................................74
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viii

Studies and Standards ........................................................................................................................74

Development.........................................................................................................................................75

Pilot Demonstrations............................................................................................................................76

Pre-Commercial Demonstrations.......................................................................................................77

Deployment Support and Incentives .................................................................................................78

APPENDIX D: Glossary.........................................................................................................................79
Draft Publication Rev # 7 Dated 6-14-2013

ix

TABLE OF FIGURES

Figure 1: California Greenhouse Gas Reduction Goals (Mobile and Stationary Sources)...............4

Figure 2: Six Truck Categories Based on Technology Applicability.................................................10

Figure 3: Truck CO2e, Average Vehicle Miles Traveled and Population by Truck Category.......12

Figure 4: Relative NOx by Truck Category..........................................................................................13

Figure 5: Relative Baseline Truck Petroleum Use, 2010......................................................................14

Figure 6: Investment in Actions, 2013-2020..........................................................................................17

Figure 7: Investment Portfolio by Strategy...........................................................................................17

Figure 8: CO2e Reduction from Roadmap............................................................................................21

Figure 9: Fuel-related CO2 Reduction Assumptions ...........................................................................23

Figure 10: Impact of Biofuel Adoption on Petroleum Reduction......................................................24

Figure 11: Biofuel Related Impact on CO2e Reduction.......................................................................25

Figure 12: Projected NOx Reductions ...................................................................................................26

Figure 13: Technology Adoption by Truck Category ........................................................................27

Figure 14: Technology Adoption all Truck Categories.......................................................................28

Figure 15: CalHEAT Technology Actions.............................................................................................30

Figure 16: Summary Timeline ................................................................................................................30

Figure 17: Summary Timeline for CalHEAT Roadmap Technology Strategies..............................31

Figure 18: Sixty-six Actions by Technology Strategy..........................................................................32

Figure 19: Hybrid Electric Technology and Action Roadmap...........................................................34

Figure 20: Electrified Auxiliaries Technology and Action Roadmap...............................................36

Figure 21: E-Truck Technology and Action Roadmap .......................................................................38

Figure 22: Electrified Power Take-off Technology and Action Roadmap .......................................40

Figure 23: Plug-in Hybrid Technology and Action Roadmap...........................................................42

Figure 24: Electrified Corridor Technology and Action Roadmap...................................................44

Figure 25: Alternative Fuel Hybrid Technology and Action Roadmap...........................................46

Figure 26: Hydraulic Hybrid Technology and Action Roadmap......................................................48
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x

Figure 27: Optimized Alternative Fuel Engine Technology and Action Roadmap........................50

Figure 28: Waste Heat Recovery Technology and Action Roadmap................................................53

Figure 29: Engine Optimization Technology and Action Roadmap.................................................55

Figure 30: Alternative Power Plant and Combustion Cycle Technology and Action Roadmap..57

Figure 31: Transmission/Driveline Technology and Action Roadmap............................................59

Figure 32: Technology Pathways ...........................................................................................................61

Figure 33: Sixty-Six Actions by Technology Strategy .........................................................................69
Draft Publication Rev # 7 Dated 6-14-2013

xi

LIST OF TABLES

Table 1: AB 32 Scoping Plan Reduction Measures Relevant to Trucks ..............................................4

Table 2: California Goals for Truck-Related CO2e Emissions in MMT by 2050 ................................8

Table 3: Truck Categories, 2010 Populations and CO2e Emissions...................................................11

Table 4: Investment Portfolio by Strategy, in Millions .......................................................................18

Table 5: Promising Technology Pathways by Truck Category..........................................................19

Table 6: Sixty-six Actions in CalHEAT Roadmap ...............................................................................70

Table 7: Studies and Standards Action Summary...............................................................................74

Table 8: Development Action Summary...............................................................................................75

Table 9: Pilot Demonstration Action Summary...................................................................................76

Table 10: Pre-Commercial Demonstration Action Summary ............................................................77

Table 11: Deployment Support and Incentives Action Summary.....................................................78
Draft Publication Rev # 7 Dated 6-14-2013

1

EXECUTIVE SUMMARY

Introduction

The California Hybrid, Efficient and Advanced Truck Research Center (CalHEAT) was 

established by the California Energy Commission in 2010 as a project operated by CALSTART 

to research, plan, and support commercialization and demonstrate truck technologies that will 

help California meet environmental policies mandated through 2050.

The role of the research center is to coordinate the development of a Research and Market 

Transformation Roadmap to deliver clear, actionable steps to help meet or exceed the 2020 goals 

for California in petroleum reduction, carbon reduction, and air quality standards, and set up a 

Roadmap for longer term goals. Medium-duty vehicles (MDV) and heavy-duty vehicles (HDV) 

account for 9% of greenhouse gases in California, and approximately 20% of fuel used.

Improvements in efficiency or reduction of petroleum use by trucks provide a substantial 

opportunity to reduce emissions.

Regulatory Context and Purpose

The State of California has passed regulations that establish emission reduction targets. The 

primary driver is AB 32 – The California Global Warming Solutions Act of 2006. AB 32 was 

signed into law with the goal of reducing 2020 greenhouse gas emissions to year 1990 levels by 

2020, and to meet more stringent ongoing environmental policies through 2050. The regulations

require a reduction of nearly 30% from the projected 2020 levels if no changes occurred, referred 

to as “Business as Usual,” and a reduction of 15% from 2009 levels.

In addition to AB 32, there are a number of overlapping State and Federal regulations aimed at 

decreasing emissions of greenhouse gases and particulate matter, improving air-quality, 

increasing biofuel use, decreasing petroleum use and more.

At the State level, the primary additional relevant regulations include AB 1007, which requires

the preparation of a state alternative fuel plan; AB 2076, which sets specific goals for State 

reduction of petroleum use; a Statewide Truck and Bus Regulation, which mandates reduced

emissions of diesel particulate matter, oxides of nitrogen, greenhouse gases and other pollutants 

from diesel-fueled vehicles; and a Diesel Risk Reduction Plan, intended to reduce the public’s 

risk exposure to diesel particulate matter by 80 percent by 2020 from 2000 levels..

In addition, Federal regulations include fuel economy and carbon emission requirements that 

will be applied to new medium- and heavy-duty trucks starting in 2014 that will drive 

emissions reductions and efficiency improvements.
Draft Publication Rev # 7 Dated 6-14-2013

2

CalHEAT Truck Classification and Baseline Report

As the first step in the development of this Roadmap, CalHEAT performed a California Truck 

Inventory Study to better understand the various types of trucks used in California, their 

relative populations, and how they are used. The analysis included nearly 1.5 million 

commercial medium- and heavy-duty trucks, grouped by weight and application, to establish a 

baseline inventory and determine fuel use and potential for efficiency and emissions 

improvements.

CalHEAT Technology Roadmap Summary and Recommendations

CalHEAT has identified 66 action items in the Roadmap to help mitigate emissions or improve 

efficiency. These clearly defined, achievable “stepping stones” provide a pathway through 

successive stages of technology development and adoption across multiple technology 

categories and vehicle platforms. The action items focus on 13 technology strategies grouped 

broadly under electrification and engine or driveline efficiency. CalHEAT collaborated in the 

development of this Roadmap with the State’s Air Resources Board, Energy Commission, Air 

Quality Management Districts, the U.S. Department of Energy, U.S. Environmental Protection 

Agency and nationally-recognized medium- and heavy-duty truck associations, manufacturers, 

and experts. With implementation of the 66 action items, the Research and Market Transformation 

Roadmap projects a reduction in 2050 of more than 40 Million Metric Tons of carbon dioxide 

equivalent emissions per year compared to existing technology, referred to hereafter as 

“Business as Usual.” Truck-related petroleum use is projected to decrease from 3.6 billion 

gallons per year in 2012 to 1.5 billion gallons per year in 2050, a decrease of 58%, or more than 2 

billion gallons per year, compared to Business as Usual. Nitrous oxide emissions are projected 

to decrease by 73% from 249,000 metric tons/year in 2012 to 66,000 metric tons/year by 2050, 

accomplished through increases in mileage per gallon and from adoption of NOx reduction 

technologies. 
Draft Publication Rev # 7 Dated 6-14-2013

3

CHAPTER 1:

Introduction and Summary 

California Policy Context

Medium- and heavy-duty vehicles are critical to California’s economy yet they are a major 

concern in relation to petroleum use and carbon dioxide emissions. These vehicles contribute

9% of California greenhouse gas (GHG) emissions and consume 20% of the total fuels used in 

California fleets1. GHG from trucks increased by 77% from 1990-2006, a growth rate three times 

greater in medium- and heavy-duty trucks than light-duty vehicles during that period. The 

California Energy Commission predicts a 42% increase in the use of diesel fuel by 20302. Diesel

is a primary fuel for medium- and heavy-duty vehicles. The U.S. Department of Energy (DOE)

predicts that the percentage of transportation GHGs that come from freight trucks will continue 

to grow, estimating a (national) shift from 17.4% in 2007 to 20.7% in 2030.3

AB 32 – The California Global Warming Solutions Act

The State of California has passed regulations that establish emission reduction targets. The 

primary driver is AB 32 – The California Global Warming Solutions Act of 2006. AB 32 was 

signed into law with the goal of reducing greenhouse gas emissions to year 1990 levels by 2020, 

and to meet more stringent ongoing environmental policies through 2050, as shown in Figure 1,

page 4). The regulations require a reduction of nearly 16% from the projected 2020 levels if no 

changes occurred, referred to as “Business as Usual,” and a reduction of6% from 2010 levels.4

Another aspect of AB 32 includes the Low Carbon Fuel Standard, which is intended to reduce 

carbon intensity of transportation fuels by at least 10% by 2020, leading to a reduction of 15 

Million Metric Tons of CO2 equivalents (MMTCO2e) by 2020. Recommended reductions 

relevant to trucks identified in the AB 32 Scoping Plan are shown in Table 1, page 4. 

 

1 California DOT, 2008 California Motor Vehicle Stock, Travel and Fuel Forecast, 2008.

2 http://ntl.bts.gov/lib/32000/32700/32779/DOT_Climate_Change_Report_-_April_2010_-

_Volume_1_and_2.pdf

3 U.S. Department of Transportation, Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions, 

2010. 

4 California Air Resource Board, AB 32 Climate Change Scoping Plan, December 2008.

< http://www.arb.ca.gov/cc/scopingplan/document/scopingplandocument.htm> 
Draft Publication Rev # 7 Dated 6-14-2013

4

Figure 1: California Greenhouse Gas Reduction Goals (Mobile and Stationary Sources)

CO2 equivalent emission reduction targets mandated by AB 32 – The California Global Warming 

Solutions Act of 2006 with the goal of reducing 2020 greenhouse gas emissions to 1990 levels and to 

meet more stringent ongoing environmental policies through 2050.

California Air Resources Board Climate Change Scoping Plan

Table 1: AB 32 Scoping Plan Reduction Measures Relevant to Trucks

Recommended Reduction Measures Relevant to 

Trucks

Reductions Counted Toward 

2020 Target (MMTCO2e)

Low Carbon Fuel Standard – Reduces carbon intensity of 

transportation fuels by at least 10% by 2020

15

Medium- and Heavy-Duty Vehicle Greenhouse Gas Emission 

Reduction

0.9

Medium- and Heavy-Duty Vehicle Hybridization 0.5

Goods Movement, Ship Electrification at Ports, System-wide 

Efficiency Improvements

3.7

AB 32 Scoping Plan measures related to CO2e emissions from transportation, with reduction targets by 

2020. The Low Carbon Fuel Standard reduction targets figure of 15MMTCO2e includes passenger cars 

as well as trucks. The Medium- and Heavy-Duty Vehicle Greenhouse Gas Emission Reduction and 

Medium- and Heavy-Duty Vehicle Hybridization measures are specific to trucks. The reductions shown 

for Goods Movement, Ship Electrification at Ports and System-wide Efficiency Improvements include 

reductions from both trucks and ships. 

AB 32 Scoping Plan and CalHEAT Vehicle and Technologies Characterization and Baseline Report
Draft Publication Rev # 7 Dated 6-14-2013

5

Other California Regulations

In addition to AB 32, there are a number of overlapping State and Federal regulations aimed at 

decreasing emissions of greenhouse gases and particulate matter, improving air-quality, 

increasing biofuel use, decreasing petroleum use and more.

At the State level, the primary relevant regulations affecting medium- and heavy-duty trucks

include: 

 AB 1007, in response to which the California Energy Commission (CEC) prepared a state 

alternative fuel plan in 20075. The plan established goals for alternative fuels penetration 

rates of 9% by 2012, 11% by 2017, and 26% by 2022. 

 AB 2076, in response to which the Energy Commission and the California Air Resources 

Board prepared and adopted a joint agency report, Reducing California’s Petroleum 

Dependence. Included in this report are recommendations to increase the use of 

alternative fuels to 20% of on-road transportation fuel use by 2020 and 30% by 20306.

 Statewide Truck and Bus Regulations, established to reduce emissions of diesel 

particulate matter (PM), oxides of nitrogen (NOx) and other criteria pollutants, and 

greenhouse gases from in-use diesel-fueled vehicles7.

 Diesel Risk Reduction Plan, intended to reduce the public’s risk exposure to diesel 

particulate matter by 80 percent by 2020 from 2000 levels8.

 Executive Order B-16-2012 establishes the goal of reducing CO2e from the transportation 

sector in 2050 to 80% less than 1990 levels. The EO further orders the state to establish 

benchmarks to achieve widespread use of zero-emission vehicles for public 

transportation and freight transport by 2020.

 

5 State Alternative Fuels Plan, December 2007, CEC-600-2007-011-CMF

6Reducing California’s Petroleum Dependence, California Energy Commission and Air Resources Boards, 

joint agency report, August 200, publication #P600-03-005.

7http://www.arb.ca.gov/regact/2008/truckbus08/revfro.pdf 

8 Emissions and Health Benefits of Regulation for In-Use Off-Road Diesel Vehicles, June 2010 

http://www.arb.ca.gov/msprog/ordiesel/documents/OFRDDIESELhealthFS.pdf
Draft Publication Rev # 7 Dated 6-14-2013

6

Federal Regulations

Federal regulations from the National Highway Traffic Safety Administration (NHTSA) include 

fuel economy and carbon emission requirements that will be applied to medium- and heavyduty trucks starting in 2014.9,10 Additionally, Phase 2 NHTSA regulations are likely to be 

implemented as early as 2019, building upon Phase 1 and incorporating new regulations to 

encourage use of new cost-effective technologies and more aggressive fuel reduction 

standards.11 This legislation will have an enormous effect on programs in California. Not only 

will it set new standards for trucks here, but the cost and expense of making trucks that meet 

the new standards may impact manufacturers in very significant ways, which may mean that 

they have fewer resources that can be devoted to California-specific programs. Understanding 

the impact of this regulation and how it will affect development of new truck technologies was 

a significant factor in CalHEAT’s effort to build an accurate model and Roadmap for the 

California fleet. 

Federal ozone regulations will affect much of California. New rules will drop exposure limits to 

.060-.070 ppm over 8 hours, phased in over 20 years beginning in 2010.12 The current limit is .075 

ppm,13 but background and other sources leave very little room for truck emissions. The South 

Coast Air Quality Management District estimates that changes to meet the new lower ozone 

levels will require a reduction in oxides of nitrogen (NOx) of 88-91% by 2030.14 Much ground 

level ozone is created by a chemical reaction between NOx and volatile organic compounds in 

the presence of sunlight. Since trucks are significant producers of NOx, it is likely that future 

ozone regulations will require further restriction on truck NOx production levels.

The Renewable Fuels Standard mandates that the American economy will be using 36 billion 

gallons of renewable fuel per year in its transportation fuel supply by 2022, with 16 billion 

gallons coming from advanced cellulosic biofuels that also reduce GHG by at least 60% relative 

to gasoline.15

Significant challenges to improvements in air quality, especially in Southern California and the 

Central Valley, are related to goods movement. In Southern California, traffic congestion, 

including that associated with the ports, and the need to reduce ozone and NOx levels, are 

driving forces for electrification of these vehicles to achieve zero and near zero emissions. The 

 

9 http://www.nhtsa.gov/fuel-economy

10 http://www.nhtsa.gov/staticfiles/rulemaking/pdf/cafe/CAFE_2014-18_Trucks_FactSheet-v1.pdf

11HD GHG Standards for HTUF, CALSTART, Sept. 17, 2012. 

12 http://www.epa.gov/glo/fr/20100119.pdf

13 http://www.aqmd.gov/legal/legalaut.html

14 Presentation to CALSTART Staff, 2010

15 USDA, A USDA Regional Roadmap to Meeting the Biofuels Goals of the Renewable Fuels Standard by 

2022, 2010.
Draft Publication Rev # 7 Dated 6-14-2013

7

Central Valley, managed by the San Joaquin Air Pollution Control District, is facing a 

particulate matter problem caused by the significant number of Class 8 tractors and over- theroad line-haul trucks that commute from southern to northern California on the Interstate 5 

corridor.

As trucks are significant contributors to greenhouse gas emissions and particulate matter, the

AB 32 Scoping Plan outlined specific areas with reduction goals applicable to medium- and 

heavy-duty trucks, as shown in Table 1, page 4. Although the State outlined reductions were 

necessary to help meet AB 32 goals, there was still much detail needed to determine how these 

segment reductions would be met, and to identify gaps and barriers both in market adoption 

and technology development that stand between the present and these goals.

To address this need, the California Hybrid, Efficient and Advanced Truck Research Center 

(CalHEAT) was established by the CEC within its Public Interest Energy Research (PIER) 

Program in 2010 to perform research into planning, commercializing and demonstrating truck 

technologies for efficient medium- and heavy-duty vehicles. The role of the research center 

during a three-year program is to coordinate the development of an overall Research and Market 

Transformation Roadmap for Medium- and Heavy-Duty Trucks and facilitate the plan 

implementation. The strategies and pathways outlined in the Roadmap are intended to deliver 

clear actionable steps to help meet the 2020 goals for California in petroleum reduction, carbon 

reduction, and air quality standards, and set up a framework, roadmap and timeline for longerterm goals. CalHEAT has collaborated in the development of this roadmap with the state’s Air 

Resources Board, Energy Commission, Air Quality Management Districts, the U.S. Department 

of Energy, U.S. Environmental Protection Agency and nationally-recognized medium- and 

heavy-duty truck associations, manufacturers, and experts.

CEC Guidance: What is the Roadmap?

The purpose of the Roadmap is to lay out an action plan for research, development and market 

transformation in medium- and heavy-duty trucks and goods movement to deliver clear 

actionable steps to meet or exceed the 2020 goals for California in petroleum reduction, carbon 

reduction, and air quality standards. The Roadmap also sets up a framework and timeline to 

address longer-term goals for carbon reduction and serves as an example that can be applied to 

other regions in transforming the heavy-duty truck sector. To do so, CalHEAT staff and 

members have examined varied technologies and strategies that can help meet these goals, and 

have looked closely at the necessary market and technological gaps that need to be addressed to 

speed the implementation of needed changes. Their efforts to thoughtfully define pathways 

and a series of achievable actions to develop and adopt successive next steps across multiple 

technology categories and vehicle platforms are what set this Roadmap apart from others that 

define goals without specifics on how to achieve them. 
Draft Publication Rev # 7 Dated 6-14-2013

8

CalHEAT Roadmap Goals 

The roadmap outlines specific, actionable steps on the identified technology pathways, with 

both technology and market milestones, including performance metrics and timeframes along 

those pathways. Achieving these steps will contribute to the effort to reach California’s 

mandated environmental policy goals.

CO2e reductions from trucks are mandated by AB 32 and California EO B-16-2012, shown in 

Table 2, below, to reduce emission levels from 35.7MMT in 2012 to 1990 levels of 29MMT/year 

by 2020, and further reduce them to 5.8MMT by 2050, a level approximately one-tenth of the 

projection under a business as usual scenario.

Table 2: California Goals for Truck-Related CO2e Emissions in MMT by 2050

Year 1990 2012 2020 2050

BAU 35.7 40.7 59.7

AB 32 and 

EO B-16-2012

29.0 35.7 29.0 5.8

Carbon dioxide equivalents in MMT for 1990 and 2012, with projections for 2050, under 

“Business as Usual” or existing technology and vehicle use, and the truck-related 

reductions mandated by California AB 32 and Executive Order B-16-2012, to reduce 

CO2e to 1990 levels by 2020, with much more stringent reductions by 2050.

California Air Resources Board Climate Change Scoping Plan16 and California Greenhouse Gas Inventory for 

199017

California’s legislative target, under AB 2076, is to reduce petroleum use 15% from 2003 levels 

by 2020._Additionally, AB 1007 establishes goals for alternative fuel penetration rates of 9% by 

2012, 11% by 2017, and 26% by 2022. AB 2076 also includes recommendations to increase use of 

alternative fuels for on-road transportation fuel use by 20% by 2020 and 30% by 2030. A 

Statewide Truck and Bus Regulation also mandates reduced emissions of diesel particulate 

matter, oxides of nitrogen, greenhouse gases and other pollutants from diesel-fueled vehicles. A

Diesel Risk Reduction Plan is intended to reduce the public’s risk exposure to diesel particulate 

matter by 80 percent by 2020 from 2000 levels. New federal regulations for fuel economy that 

take effect in 2014 for medium- and heavy-duty trucks will also drive emissions reductions and 

fuel efficiency improvements.

 

16 California Air Resource Board, AB 32 Climate Change Scoping Plan, December 2008. 

17 California Greenhouse Gas Inventory, 1990, page 10,

http://www.arb.ca.gov/cc/inventory/1990level/1990level.htm
Draft Publication Rev # 7 Dated 6-14-2013

9

During the initial term of CalHEAT’s CEC-PIER agreement, the research center has focused on 

the following three goals: 

 Development of the research Roadmap described in this report to advance science and 

technology for medium- and heavy-duty trucks,

 Research and data collection on advanced Class 8 trucks, plug-in trucks, and alternative 

fuel, high-efficiency hybrid trucks, and

 Technology transfer activities geared to end-users, manufacturers, suppliers and 

organizations suited to combining technical and commercial capabilities. 

Technologies that address one area of concern may have a positive, neutral or negative impact 

on other areas of concern, so all the regulations noted in the preceding policy section were 

considered during the development of this Roadmap. The goal of the Roadmap is to find 

solutions that provide co-benefits: solution pathways that meet and address the overlaps in all 

these varying regulations and goals, while also addressing market realities.

State of the Industry by CalHEAT Classification

As the first step in the development of this Roadmap, CalHEAT performed a California Truck 

Inventory Study18 to better understand the various types of trucks used in California, their 

relative populations, and how they are used. As the State looks to technologies with the ability 

to reduce petroleum consumption or emissions, it is imperative to understand that specific 

technologies may have widely varying impacts depending on a truck’s characteristics and how 

it is used. For example, a box truck used for heavy urban cycles may benefit greatly from 

hybridization or electrification, whereas a truck used to drive between Los Angeles and San 

Francisco may benefit more from aerodynamic improvements and light-weighting.

The analysis included nearly 1.5 million trucks, ranging in size from Class 2B to Class 8. This 

number is based on California registration figures for commercial trucks in the weight category 

2B and above, via the Polk database.19 The vehicle classes included in the inventory are shown 

in Figure 2 below, grouped both by weight and use. Class 2B pickup trucks and vans registered 

to individuals were eliminated under the assumption that most, if not all, were non-commercial 

vehicles.

 

18 Jennings, Geoff, and Brotherton, Tom. (CalHEAT). California Truck Inventory and Impact Study, 

June, 2012. http://www.calstart.org/Projects/CalHEAT/Presentations-and-Publications.aspx 

19 https://www.polk.com/knowledge/reports CalHEAT worked with Polk to create a custom dataset from 

their database, which covers registered vehicles in CA.
Draft Publication Rev # 7 Dated 6-14-2013

10

Figure 2: Six Truck Categories Based on Technology Applicability

Truck classifications, by weight and application, in the 2010 CalHEAT Truck Inventory Study.

California Hybrid, Efficient and Advanced Truck Research Center
Draft Publication Rev # 7 Dated 6-14-2013

11

For the purposes of CalHEAT’s Roadmap data, it was apparent that the weight classes were not 

sufficient to evaluate the impact of technology. With significant input from the CalHEAT 

Technology Advisory Group and the CalHEAT Advisory Council, six categories were 

developed. The intent behind the formation of their categories was to group trucks that are used 

in similar ways, such that it could be assumed that there may be similar impacts from 

technologies. A Class 4 truck in heavy urban use might see a different percentage improvement 

from hybridization than a Class 6 truck in similar use would achieve. However, that Class 4 

urban truck would be more similar to a Class 6 urban truck than a Class 4 truck primarily used 

for long distance freeway driving in how it is affected by a given technology. 

Table 3, below, shows the 2010 California truck population by application and the contribution 

to CO2e emissions both in MMTCO2e per year and on a percentage basis. Figure 3, page 12, 

shows relative CO2e emissions by truck category and miles travelled. Relative NOx emissions, 

which contribute to the development of ozone, are shown by truck category, truck population 

and miles traveled in Figure 4, page 13.

Table 3: Truck Categories, 2010 Populations and CO2e Emissions

Vehicle 

Category

Truck 

Population

% Population Average 

VMT

CO2e 

(MMT/yr)

%CO2e

Tractors - OTR 175,000 12% 85,000 12.9 38%

Tractors – Short 

Haul/Regional

111,000 8% 55,000 6.3 18%

Class 3 – 8 

Work - Urban

253,000 17% 25,000 3.6 11%

Class 3 – 8 

Work –

Rural/Intracity

295,000 20% 35,000 6.1 18%

Class 3 – 8 

Work – Work 

Site

77,000 5% 13,000 0.8 2%

Class 2B/3 

vans/pickups

531,000 36% 21,000 4.2 12%

Unknown 15,000 1% 8,192 0.1 0%

Total 1,457,000 100% 34,255 34.0 100%

California truck population by weight class and application, along with average vehicle miles traveled, 

CO2 equivalent emissions in MMT/year, the percentage of vehicles by category, and percentage 

contribution to total truck CO2e emissions.

California Hybrid, Efficient and Advanced Truck Research Center calculations
Draft Publication Rev # 7 Dated 6-14-2013

12

Figure 3: Truck CO2e, Average Vehicle Miles Traveled and Population by Truck Category

The California truck population analyzed in the 2010 CalHEAT Truck Inventory and Impact Study, shown 

by CO2e emissions, truck category and relative population, and annual vehicle miles travelled. The size of 

each ball represents the CO2e emissions for the truck category.

California Hybrid, Efficient and Advanced Truck Research Center calculations, and data from Polk Knowledge Base
Draft Publication Rev # 7 Dated 6-14-2013

13

Figure 4: Relative NOx by Truck Category

The six truck categories in the CalHEAT study shown by truck population, annual vehicle miles travelled 

and percentage contribution to total truck nitrogen oxide emissions. The size of each ball represents the 

NOx emissions for the truck category.

California Hybrid, Efficient and Advanced Truck Research Center calculations

Truck Fuel Use

The medium- and heavy-duty vehicle market uses more diesel than gasoline. This is not 

because there are more diesel trucks on the road; in fact there are more gasoline vehicles by 

total number. However, because the heaviest trucks use the most fuel, and are nearly 100% 

diesel, total diesel fuel use is higher. As one moves up the weight classes, the percentage of 

vehicles goes from primarily gas on the light duty end to nearly 100% diesel in the heaviest 

Class 8 segment.

The CEC reports approximately 15 billion gallons of gasoline used in CA in 2008, mostly in 

light-duty passenger cars and light trucks. This amount is projected to decline annually through 

2020. According to the same report, diesel fuel use, in contrast, is estimated at 3.6 billion gallons, 

and is expected to increase by 1.5% annually during the same period In 2010, trucks accounted

for 20% of the petroleum fuels (gasoline and diesel combined) used in California, or a total of 

approximately 3.5 billion gallons of which 60% was diesel.
Draft Publication Rev # 7 Dated 6-14-2013

14

Figure 5: Relative Baseline Truck Petroleum Use, 2010

The six truck categories in the CalHEAT study shown by truck population, annual vehicle miles travelled 

and their relative use of petroleum. The size of each ball represents the percentage of fuel used by trucks 

in that category.

California Hybrid, Efficient and Advanced Truck Research Center calculations

Technology Roadmap Summary Results

The technology strategies listed below were those identified by CalHEAT staff, its Advisory 

Council, and Technology Working Groups as the most feasible ways to improve efficiency and 

reduce emissions in MDV and HDV. The seven [only six in list on next page...] strategies

grouped under Electrification and six strategies related to Engine & Driveline comprise the 

thirteen strategies with 66 specific actions in this Roadmap. The technology strategies and 

related actions are described in Chapter 2, with supporting information on the actions shown in 

Appendix B. The six strategies grouped under chassis, body, and roadway systems are also 

important and will contribute to reduction of fuel use and efficiency improvements. However, 

they are strategies that are already receiving reasonable attention by the industry. As a result, 
Draft Publication Rev # 7 Dated 6-14-2013

15

they are not included in specific action items recommended in this Roadmap. Additionally, 

investments in infrastructure, clean fuels, and other complementary needs and strategies are not 

included in this Roadmap.

Technology Strategies

Electrification

 Hybrid Electric

 Electrified Auxiliaries E-Trucks

 Electrified Power Take-off (EPTO) 

 Plug-in Hybrid Electric

 Electrified Corridor

 Alternative Fuel Hybrids

Engine and Driveline

 Hydraulic Hybrid

 Optimized Alternative Fuel Engines

 Waste Heat Recovery

 Engine Optimization

 Alternative Power Plants and Combustion Cycles

 Transmission and Driveline Improvements

Chassis, Body, and Roadway Systems

 Light weighting

 Aerodynamics

 Lower Rolling Resistance

 Intelligent Vehicle Technologies, e.g. Forecasting, Adapting

 Corridors and Platooning

 Longer, Heavier Single Trucks

Investment

The projected investment required for the 66 action items included in this Roadmap between 

2013 and 2020 totals $434,700,000. These investments continue the ongoing momentum towards 

California’s environmental goals and act as a launch point for cost effective commercial product 
Draft Publication Rev # 7 Dated 6-14-2013

16

introductions. The focus of these CalHEAT investments are to assure the development and pilot 

demonstration of technologies that culminate in providing the fleets with a return on 

investment of two to four years by 2020. 

The CalHEAT investment analysis scenario also assumes the following:

 Aggressive new state and federal regulations by 2020 that motivate manufacturers to 

produce, and fleets to purchase, large numbers of advanced technology vehicles. These 

include requirements that drive NOx emission reductions by up to 90% as well as Green 

House Gas reductions similar in magnitude to those put in place for the light duty 

vehicle market under CAFE rules.

 Significant parallel investment must be made in:

o vehicle fueling infrastructure

o cleaner and renewable fuels

o advanced technology vehicle component manufacturing and workforce training.

 Economies of scale significantly drive down vehicle technology costs as production 

volumes increase.

 Fleets accept new technologies as vehicle payback period approaches two years.

Further, these investment projections do not include transformation of California’s light-duty 

vehicles, off-road equipment, marine vessels and locomotive fleets. Significant additional 

investments and/or regulations to accelerate development and deployment of advanced 

technology vehicles and equipment could be needed for the South Coast and San Joaquin Valley 

Air Basins to meet the federal eight-hour ozone standard as required by 2023.

Incentives were developed to jumpstart new technologies, to support fleet adoption and 

overcome perceived fleet risks. The deployment incentives proposed here are to help build 

initial volumes to launch points, not to fully fund fleet turnover. Additional incentive 

investment would likely be needed to reach larger fleet adoption in the long run. Moreover, the 

total investment need is highly dependent on the specific investment strategy. CalHEAT 

focuses on early stage R&D in addition to deployment, in order to drive down technology costs 

and move past the need for purchase incentives. However, California is currently investing 

almost exclusively in late stage demonstrations and early deployments. A continued focus on 

late-stage investments would slow technology advancement and increase the amount needed 

for purchase incentives. 

The CalHEAT investment analysis scenario assumes very aggressive fuel economy standards to 

be set by EPA/NHTSA under phase two of the Greenhouse Gas initiative for heavy duty 

vehicles. As an example an aggressive fuel economy standard for over the road Class 8 Tractors

was projected at a 100% improvement. It is anticipated that the standards would be in place by 

2020 and would find support by California for early adoption by 2018. In this manner the 

suppliers will likely self-invest in the commercialization of cost effective technologies. Without 
Draft Publication Rev # 7 Dated 6-14-2013

17

aggressive standards of at least a 50% increase, or delays in these standards, additional 

investment in incentives would be required to drive market adoption and acceptance. 

Investment for the major categories Electrification and Engine and Driveline, is shown in “

Figure 6” for two three-year periods from 2013-2016 and 2017-2020. Grouped by action, 68% of 

the projected investment needed to achieve the emission and efficiency targets would be in 

development and demonstrations, and 32% would be in deployments and incentives. By 

strategy, Electrification-related actions comprise 46% of the projected investment, while 54% 

would be for Engine & Driveline improvements. Chassis, Body, and Roadway Systems 

improvements have not been in included in this Roadmap, in either the investments shown or 

as part of the 66 action items because many advances in these areas are already underway by 

truck manufacturers. In addition these investment do not include any new unidentified actions 

that are likely to become apparent up to and beyond 2020

Further detail showing projected investment required by specific strategy to achieve the 66 

action items is shown in Figure 7, page 17 and Table 4, page 18.

Figure 6: Investment in Actions, 2013-2020

 

Projected investment by 2020 needed to address the 66 action items identified in the CalHEAT Roadmap. 

Figure 7: Investment Portfolio by Strategy
Draft Publication Rev # 7 Dated 6-14-2013

18

Technology strategies identified by CalHEAT for medium- and heavy-duty trucks to achieve emissions 

reductions and efficiency improvement objectives by 2020, by strategy, showing percentage of emphasis.

California Hybrid, Efficient and Advanced Truck Research Center calculations

Table 4: Investment Portfolio by Strategy, in Millions

Technology $ Million Percentage

Alternative Power Plants and Combustion 

Cycles

$60.5 14%

Optimized Alternative Fuel Engines $57.0 13%

Optimized Engines $47.0 11%

Hybrid Electric $45.4 10%

Hydraulic Hybrid $45.4 10%

Plug-in Electric Hybrid $43.4 10%

E-Trucks $41.5 10%

Alternative Fuel Hybrids $37.9 9%

Waste Heat Recovery $28.0 6%

Electrified Corridor $19.5 4%

Electric Power Take-off $5.1 1%
Draft Publication Rev # 7 Dated 6-14-2013

19

Electrified Auxiliaries $5.6 1%

Total $434.7 100%

Projected investment required to accomplish the technology strategies identified by CalHEAT in the 

Roadmap for medium- and heavy-duty trucks to achieve emissions reductions and efficiency 

improvement objectives by 2020, shown by millions of dollars and relative percentage, by technology 

strategy.

California Hybrid, Efficient and Advanced Truck Research Center calculations

Results

The Market and Transformation Roadmap projects a reduction in emissions through advanced 

truck technologies by 2050 of more than 40 MMTCO2e emissions compared to existing 

technology, or “Business as Usual”. These projected results are the expected outcome of

implementation of the 66 action items in the Roadmap. Table 5, below, summarizes feasibility 

by CalHEAT truck category of the 13 technology strategies grouped broadly under 

Electrification and Engine and Driveline Efficiency. Solid circles represent technology strategies 

anticipated to make noticeable contributions in the corresponding truck category by 2020, half 

circles represent technology strategies expected to be implementable after 2020 with noticeable 

results, and the empty circles indicate technology strategies not applicable to the truck category 

or not expected to offer significant benefits.

Table 5: Promising Technology Pathways by Truck Category

The 13 technology strategies deemed most feasible by the CalHEAT research are shown in this chart.

Solid circles represent the technologies in the Roadmap that are expected to contribute to noticeable 

CO2e reductions by 2020. Half circles represent technologies expected to be implementable after 2020 

with noticeable results. The empty circles indicate technologies not expected to offer significant results in

that truck category.

California Hybrid, Efficient and Advanced Truck Center Research

Pathway Technology 

Class 7-8 

Urban 

Class 8 

OTR 

C 3 – 8 

Work Site

Class 3 – 8 

Urban 

Class 3 – 8 

Rural 

Class 2b – 

3 Vans/ 

trucks 

Hybrid Electric 

Electrified Auxiliaries

E-Trucks 

Electric Power Take-off

Plug-in Hybrids

Electrified Corridor

AF Hybrid

Hydraulic Hybrid 

Optimized AF Engine

Waste Heat Recovery 

Engine Optimization

Alternative Power Plants & 

Combustion Cycles

Transmission and Driveline 

Engine and Driveline Electrification 
Draft Publication Rev # 7 Dated 6-14-2013

20

The technology evaluation groupings below were the initial technology pathways considered to 

have the greatest potential for reducing emissions and fuel use, and led to the selection of the 13 

technology strategies identified in the Roadmap. These evaluation groups have been used in

some of the long-term projections, including the Technology Adoption Charts shown in 

Category , page 27 and Figure 14: Technology Adoption all Truck Categories, page 28. 

Technology Evaluation Grouping

Baseline Waste Heat Recovery

Engine Optimization

Transmission and Driveline Improvements

Light-weighting

Aerodynamics

Lower Rolling Resistance

Intelligent Vehicle Technologies, e.g. Forecasting and Adapting

Corridors and Platooning

Longer, Heavier Single Trucks

New Combustion Alternative Power Plants and Combustion Cycles

Fuel Cells Alternative Power Plants/Alternative Fuels

Hydraulic Hydraulic Hybrid

HEV Hybrid Electric

Electrified Auxiliaries

Electrified Power Take-off (EPTO)

xEV E-Trucks

Plug-in Hybrid Electric

Electrified Corridors
Draft Publication Rev # 7 Dated 6-14-2013

21

CO2e Reduction from the CalHEAT Roadmap

Through implementation of the 66 action items identified in this Roadmap, a reduction of 

approximately 5 MMTCO2e can be achieved by 2020 from the “Business as Usual” projected 

level without these changes, and a reduction of over 40 MMTCO2e could be achieved by 2050.

Figure 8, below, shows the impact by CalHEAT vehicle category compared to “Business as

Usual.” The Roadmap reductions are based on technology improvements to increase mileage 

or reduce fuel consumption, including increased adoption of hybrids and E-Trucks. The model 

is based on a 25% adoption rate of biofuels by 2050. The descending line shows the targeted 

reduction called for by AB 32 and EO B-16-2013. The gap between the projected reduction and 

the Roadmap reductions could be met by a higher rate of adoption of biofuels. 

Figure 8: CO2e Reduction from Roadmap

The combined impact of the 66 Actions included in the CalHEAT Roadmap as projected to reduce CO2

equivalent emissions by 2050. Reduction is shown for each of the six CalHEAT truck categories defined 

in the Roadmap by size and application. The ascending line for “Business as Usual” shows projected 

emissions without the Roadmap Actions. The dashed line shows the reduction goals set by AB 32 and 

EO B-16-2012.

California Hybrid, Efficient and Advanced Truck Research 
Draft Publication Rev # 7 Dated 6-14-2013

22

Fuel-Related Reductions

Use of biofuels and decarbonization of electricity and hydrogen used in fuel cells are expected 

to account for a portion of the projected CO2 reduction from the Roadmap actions, as shown in

Figure 9, below. Increased use of diesel biofuel is projected in the Roadmap as one of the ways 

to reduce carbon and petroleum-based fuels. Although most gasoline sold in California is 

currently 10% ethanol, only a very small percentage of today’s diesel fuel includes biodiesel. 

The CalHEAT model is based on an assumption of increased use of biodiesel to 5% by 2020, 

which is expected to be achieved by blending biodiesel with petroleum-based diesel. The 

model assumes an increase to 20% biodiesel by 2035. These assumptions were developed in 

part on the Air Resources Board Advanced Biofuel Market Report 2011 which details expected 

increases in availability of biodiesel through 2015. 20 Biofuels give off approximately the same 

amount of CO2 as petroleum based fuels during combustion. However, they reduce the net 

amount of carbon in the air because the plants from which the biofuels are derived use CO2 as 

the carbon source for the complex oil molecules in which the plant stores energy.

Electricity decarbonization is another way to reduce carbon impact, by changing the source of 

energy used to generate power to more renewable sources. The fuel curve assumptions used in 

the model are based on 30% renewable sources of energy for power generation by 2020, based 

on targets established in 2006 by AB 32. The fuel curves in the Roadmap also assume an 

increase to 95% renewable sources of energy for generation of electricity by 2050, based on a

published model used to analyze the potential for electricity decarbonization.

21

Hydrogen decarbonization, a way to extract hydrogen in a usable form from renewable sources,

is expected to become cost-effective in the future as an energy source in fuel cells. As a result, it 

is projected to make a contribution in carbon reduction beginning in 2020, and continue through 

2050. The Roadmap model assumes that 33% of hydrogen will be from solar-generated 

electrolysis or renewable natural gas through 2035. After 2035, the curve follows that used for 

electricity. For additional information on assumptions used and how the Roadmap model was 

developed, please see Appendix A, page 65.

 

20 California Air Resources Board, Advanced Biofuel Market Report 2011, Meeting the California LCFS. 

http://www.arb.ca.gov/fuels/lcfs/workgroups/advisorypanel/20110825_e2_report.pdf

21 Williams, James H.; DeBenedictis, Andrew; Ghanadan, Rebecca; Mahone, Amber; Moore, Jack, Morrow, William R., III; 

Price, Snuller; and Torn, Margaret S. 2011. The Technology Path to Deep Greenhouse Gas Emissions Cuts by 2050: The 

Pivotal Role of Electricity. Science, April 20, 2012.
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Figure 9: Fuel-related CO2 Reduction Assumptions

Increased use of biofuels and decarbonization achieved by using renewable energy sources will 

contribute to the CO2e reductions projected by the CalHEAT Roadmap. Significant reductions can be 

achieved through electricity decarbonization, by using clean or renewable energy sources for electric 

power, and hydrogen decarbonization, a process that removes carbon while creating hydrogen for use in 

fuel cells.

California Hybrid, Efficient and Advanced Truck Research calculations

The Roadmap projections for CO2e and petroleum use are based in part on biofuel adoption, 

assuming a moderate adoption rate of 25% by 2050. At this level of biofuel adoption, petroleum 

use decreases from 3.5 billion gallons per year across all truck categories to 1.5 billion gallons 

per year in 2050, as shown in the chart on the left in Figure 10, below. Compared to 2012 levels, 

this would result in a 6.9% reduction in petroleum used by trucks in California by 2020, a 41% 

reduction by 2035, and a 58% reduction by 2050. The rate of adoption of biofuels will be 

dependent on how fast they ramp to a competitively priced commercial scale, but if the 

adoption rate is higher, much greater reductions in petroleum use and CO2e can be achieved. 

Figure 10: Impact of Biofuel Adoption on Petroleum Reduction shows reduction curves for 

petroleum of 25% adoption by 2050 on the left and 95% biofuel adoption on the right. In the 

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

2010 2020 2030 2040 2050

% CO2 Reduction from Fuel Type

Year

Diesel Biofuel Addition

Hydrogen Decarbonization

Electricity Decarbonization
Draft Publication Rev # 7 Dated 6-14-2013

24

high adoption rate scenario, petroleum use decreases from a total of 3.5 billion gallons per year 

across all truck categories in 2012 to 0.098 billion (98 million) gallons per year in 2050. This 

scenario results in a 20% reduction in petroleum use by 2020, a 66% reduction by 2035, and a 

97% reduction by 2050, compared to 2012 levels.

Figure 10: Impact of Biofuel Adoption on Petroleum Reduction

The CalHEAT Roadmap assumes a 25% adoption rate for biofuels by 2050, which is projected to result in 

a reduction of petroleum-based fuels from 3.6 billion gallons/year in 2012 to 1.5 billion gallons/year in 

2050, as shown in the chart on the left. A higher rate of adoption of biofuel can further reduce petroleum 

requirements, as illustrated in the chart on the right.

California Hybrid, Efficient and Advanced Truck Center calculations

Impact of Biofuel Adoption on CO2e Reduction

The impact on CO2e emissions from a transition to biofuels is shown in Figure 11, below. The 

chart on the left shows the curves used for the projections in this Roadmap, using a 25% biofuel 

adoption rate, which results in a decrease of CO2e from 36MMT in 2012 to approximately 

16MMT/year in 2050. Compared to 2012 levels, the reductions are 4.9% by 2020, 33% by 2035, 

and 55% by 2050. 

As with petroleum use, CO2e emissions under a higher adoption rate of biofuels could be much 

lower. In the comparative curve on the right side of Figure 11, which is based on a 95% biofuel 

adoption rate, CO2e could be reduced to 4.9MMT in 2050, with the largest reductions coming 

from tractors, in both the short-haul /regional and OTR categories. Compared to 2012 levels, this 

could result in an 86% reduction of CO2e in 2050.
Draft Publication Rev # 7 Dated 6-14-2013

25

Figure 11: Biofuel Related Impact on CO2e Reduction

The CalHEAT Roadmap assumes a 25% adoption rate for biofuels by 2050, which would result in a 

reduction of CO2e from 36MMT/year in 2012 to 16MMT/year in 2050, as shown in the chart on the left. A 

higher rate of adoption of biofuel can further reduce CO2e, as shown in the example on the right, which

assumes a 95% adoption rate by 2050. At a 95% adoption rate, a reduction to 4.9MMT/year of CO2e

could be achieved across all truck categories, which would reach the California target levels defined for 

2050. 

California Hybrid, Efficient and Advanced Truck Center calculations

NOx Reduction

The Roadmap projects a reduction in NOx from 249,000 MT/year in 2012 to 67,000 MT/year by 

2050, as shown in Figure 12, below. On a percentage basis, the reductions are 4% by 2020, 51% 

by 2035 and 73% by 2050, and are expected to be achieved through increases in miles per gallon, 

beginning in 2012, and from adoption of NOx reduction technologies beginning in 2020. Under 

the assumptions used, NOx reduction does not vary with the biofuel content.
Draft Publication Rev # 7 Dated 6-14-2013

26

Figure 12: Projected NOx Reductions

CalHEAT Roadmap projections result in a reduction of NOx, a greenhouse gas that is a precursor to 

ozone, from 249,000 metric tons per year in 2012 to 67,000 metric tons per year in 2050. The highest 

reductions will result from short-haul/regional and over-the-road tractors.

California Hybrid, Efficient and Advanced Truck Center calculations

Technology Adoption 

Projected timelines for technology adoption and the impact by number of vehicles is shown in

Category , page 27, by CalHEAT truck category and in Figure 14, page 28, for all six truck 

categories combined. Baseline technologies include waste heat recovery; engine optimization;

transmission and driveline improvements; light-weighting; aerodynamics; lower rolling 

resistance; intelligent vehicle technologies such as forecasting and adapting; corridors and 

platooning; and longer, heavier single trucks. The other evaluation groups are New 

Combustion; Fuel Cells; Hydraulic Hybrids; Hybrid Electric Vehicles (HEV), which includes 

hybrid-electric trucks, electrified auxiliaries and power take-off; and xEV which includes ETrucks with full electric powertrains, and plug-in hybrid electric vehicles; and Electrified 

Corridors, which provide external power to electric powertrains for ZEV Corridors. By 2020, 

more than 1.7 million trucks are expected to have adopted some of the recommended 

technologies, and by 2050, projected adoption of some of the Roadmap technologies will affect 

approximately 2.4 million trucks, as shown in Figure 14.
Draft Publication Rev # 7 Dated 6-14-2013

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Figure 13: Technology Adoption by Truck Category 

Projected adoption of CalHEAT Roadmap Action Items by Technology Group and Truck Category, shown 

by number of vehicles affected from 2010 through 2050.

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Figure 14: Technology Adoption all Truck Categories

Projected adoption of CalHEAT Roadmap Action Items by Technology Group for all CalHEAT Truck 

Categories combined, shown by number of vehicles affected, 2010 through 2050. By 2020, the Roadmap 

action items could result in efficiency and emission improvements in approximately 1.7 million trucks, and 

by 2050, this impact could increase to 2.4 million trucks.

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CHAPTER 2:

Technology Solutions and Action Roadmaps

From the information gathered in its initial Inventory of the California Truck Fleet, and the 

Forums held with CalHEAT Advisory Council and Technical Advisory Group members, 

various technology pathways were identified as a starting point for discussion and analysis as 

the Research and Market Transformation Roadmap for Medium- and Heavy-Duty Trucks, as described 

in the Technology Evaluation Grouping, page 20.

From these pathways, 13 technology strategies were selected as those most likely to provide 

achievable opportunities to reduce petroleum use and carbon emissions, and increase efficiency.

They are shown in shown in Figure 17, Summary Roadmap Timelines, page 31. Actionable 

steps with milestones and timelines for technology research, development, demonstration and 

market introduction were identified for each of the strategies. The overall Roadmap covering 

the 13 technology strategies includes 66 action items. Each of these technology strategies is 

addressed in a separate section of this chapter, beginning with Hybrid Electric on page 33.

Introduction to the Roadmap

The CalHEAT Roadmap uses five types of actions to accelerate the development and 

commercialization of technology solutions, detailed in Figure 15, below. “Studies and 

Standards” cover business case or feasibility research prior to development of initial prototypes.

“R&D”, “Pilot Demonstrations” and “Pre-Commercial Demonstrations” are actions that cover 

the development and pre-market stages of bringing new technology to market. “Deployment 

Support and Incentives” for market-ready technologies provide regulatory or financial support 

to encourage adoption.
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Figure 15: CalHEAT Technology Actions

CalHEAT uses five types of actions to accelerate technology solutions in the market.

California Hybrid, Efficient and Advanced Truck Research Center

To convey the timelines associated with each action, summary timelines are used throughout 

the Roadmap. As shown in Figure 16, below, blue arrows are used for the four actions covering 

pre-market activity, and green arrows are used for deployment support and financial incentives

to support market-ready technologies. The development actions or development stage are 

embedded in the arrow. 

Figure 16: Summary Timeline

Summary timelines are used in the summary Roadmap timelines and in the 13 technology and action 

roadmaps that group goals and actions by technology strategy to show the development stages, actions 

and the period of time projected for each. 
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California Hybrid, Efficient and Advanced Truck Research Center

An overall summary timeline for the development stages of the Roadmap, by technology 

strategy, is shown in Figure 17, below. The 66 actions, identified by number and the type of 

action, from study or standard through deployment, are grouped by technology strategy in

Figure 18, page 32.

Figure 17: Summary Timeline for CalHEAT Roadmap Technology Strategies

Summary roadmap timeline for 13 technologies identified in the CalHEAT Research and Market 

Transformation Roadmap as promising strategies to contribute to both reduction of carbon and decreased 

use of petroleum by more than 70% by 2050 from 2012 compared to “Business as Usual.”

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Figure 18: Sixty-six Actions by Technology Strategy

The 66 actions to reduce petroleum, emissions or improve truck efficiency 

are grouped by technology strategy and identified by action category, from 

studies and standards through deployment. Refer to Table 6, Appendix B, 

page 70, for a numerical list, timeline and description. 

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Hybrid Electric

Hybridization allows significant increases in vehicle efficiency by reducing fuel consumption.

Hybrid vehicles use two distinct power sources to move the vehicle. In a typical medium- or 

heavy-duty hybrid electric truck, an internal combustion engine (ICE) fueled by gasoline or 

diesel powers the vehicle when sufficient electrical power is not available. During braking, 

descending a hill, or other times when excess kinetic energy is available, the hybrid system 

captures and stores it. This stored energy can then be used to help power the vehicle with 

electricity, thus reducing the amount of fuel required.

Further electric hybrid truck improvements to achieve higher fuel economy; optimize, downsize

and integrate the engine; increase energy storage; and improve ROI are summarized in four 

technology/action stages in Figure 19, below. The technology improvements for each stage, 

described in the upper series of boxes, can be achieved through the corresponding actions 

shown below them.

Over the four stages shown in the roadmap the ultimate goal will be to achieve a two-to-four 

year ROI. The key strategy to accomplish this will be an evolution of improved levels of system 

and chassis integration complemented by improvements in energy storage costs and 

performance.

Characteristics of hybrid trucks that were commercially available in 2012 are shown as Stage 1 

technology. They provide a 20% improvement in fuel economy over conventional trucks, but 

may not have engine off at idle or electrified auxiliaries.

Stage 2 includes an economic goal of payback in 5 years without incentives. Technical 

characteristics include engine off at idle, electrified auxiliaries, improved integration, fuel 

economy gain of 30-40%, and CA on-board diagnostic (OBD) compliance. Related actions 

include efforts to overcome California OBD issues and support development of an SAE 

standard for OBD interfaces (J1939), a study on battery packs and interface controls (shared 

with E-Trucks), pre-commercial demonstration of Stage 2 technology, and deployment 

incentives for 1,000 Stage 2 hybrids drivelines when they become commercially available. Stage 

3 hybrid electric advances, targeted for 2014-2016, call for larger, lower-cost electric motors, 

greater integration, and optimized engine systems. To achieve these objectives, greater 

cooperation among the engine, drivetrain and platform manufacturers is needed. Stage 3 

actions include R&D prototype projects and pilot demonstrations of hybrid-specific optimized 

and downsized engines.

Stage 4 advances call for a two-to-four-year ROI and the emergence of more electric or mild 

hybrid electric over-the-road (OTR) trucks as enhanced performance from larger energy storage 

capacity and decreased ROI makes payback feasible for OTR tractors. A Stage 4 Roadmap 

action includes pre-commercial demonstration funding for a more-electric OTR truck. 
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Figure 19: Hybrid Electric Technology and Action Roadmap

Four stages of technology development have been defined to advance hybrid electric trucks through 

2020, achieving increased fuel economy through features such as engine off at idle, electrified auxiliaries, 

hybrid-optimized and downsized engines for greater efficiency, and increased energy storage. The 

actions needed to achieve them are shown below the arrows of the summary timeline.

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Electrified Auxiliaries

Auxiliary loads or accessories, such as air conditioning, alternators, power steering, power 

brakes, the engine water pump, air compressor, power-steering pump, and cooling fans can 

represent up to 9% of the energy used in a truck. In many cases, the energy they require can be 

reduced by converting them to electric power. Electrically-powered accessories such as the air 

compressor or power steering operate only when needed, but these accessories impose a 

parasitic demand all the time when they are engine driven. In other cases, such as the cooling 

fans or the engine water pump, electric power allows the auxiliary load to run at speeds 

independent of the engine speed, which can reduce power consumption.22 The use of a hybrid 

system, thermo-electrics, or an electric turbocompound provides a source of electrical energy 

that can be used to drive auxiliaries that are engine-driven on today’s vehicles. Electrified 

accessories are a critical enabling technology for E-trucks, Plug-In Hybrid Trucks, idle off for 

Hybrids and the further electrification of Class 8 Over-the-Road Tractors.

Electrifying components is essential in many emerging truck systems because of the efficiency 

benefit that can be gained. This is true even on otherwise conventional powertrains, but 

becomes especially important with hybrid powertrains, and critical when considering the 

ability for a hybrid to operate in electric-only or engine-off modes. Without electrified power 

steering and brakes, the vehicles cannot operate in these modes.

The CalHEAT Technology and Actions Roadmap for Electrified Auxiliaries is shown in Figure 

20, page 36. Stage 1 development was already underway in 2012. The objective of converting

auxiliary loads to electric power is to reduce fuel used by HEV or PHEV trucks operating in idle 

mode just to power accessories. Technical characteristics of the Stage 1 electrified auxiliaries 

commercially available in 2012 are that they are based on off-the-shelf industrial motors and 

DC-to-DC converters, and typically include pumps, power steering, fans and compressors.

Stage 2, from 2014 to 2017, targets are economical implementation of integrated DC-to-DC and 

DC-to-AC electronics to lower costs, improve functionality, simplify integration, and provide 

commonality across truck classes and platforms. One of the barriers to adoption of such 

accessories is non-standard voltages across vehicle platforms, so one Roadmap action includes 

development of standards for voltage variants and J1939 signal controls. Other actions include

R&D to develop purpose-designed electronics that can operate in a shared architecture for DCto-DC converters, such as auxiliary drives, power steering, and pumps integrated into vehicles.

Stage 3 goals are to achieve purpose-designed pumps and compressors operating with Stage 2 

electronics to improve efficiency and achieve a two-to-three-year ROI for components on 

conventional Line Haul and other Class 7-8 tractors. Pilot demonstrations for validation of 

electrified auxiliaries in Class 7-8 tractors and Line-Haul trucks are projected for 2017 to 2019. 

 

22 National Academy of Sciences site visit to Daimler/Detroit Diesel, April 7, 2009.
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Figure 20: Electrified Auxiliaries Technology and Action Roadmap

Three stages of technology development for electric-powered accessories are shown above. The actions 

for Stage 1 were already underway by truck manufacturers in 2012 and are being deployed. The actions 

for Stage 2 and Stage 3 development focus on voltage standards and purpose-designed electronics, with 

validation of electrified auxiliary loads in line-haul trucks planned for Stage 3, 2018-2019. 

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E-Trucks

There is a distinct category of zero-emission trucks with electric motors and powertrains, 

referred to as E-Trucks, which do not include a combustion engine. Their environmental 

footprint is primarily defined by the source of the electricity. Clean sources have a large 

environmental benefit, and even “dirty” sources of electricity tend to show a net “well-towheels” benefit for electric vehicles. Electric motors are also efficient and able to produce 

maximum torque, giving EVs strong driving characteristics, particularly in stop-and-go or 

urban driving situations. The torque characteristics of electric motors are well-suited for moving 

heavy loads, as evidenced by their long use in freight trains, and suggest that the upper limits of 

their power capabilities will not be tested in trucks. Electric motors also offer the ability to 

operate with very low noise, an advantage in certain applications. 

Currently, EVs have some disadvantages over conventional vehicles, primarily in cost, weight 

and range. EV components are relatively expensive, and storing electricity using currently 

available technology is expensive, bulky, and heavy. The California Energy Commission 

estimates the current incremental cost for a fully-electric medium- or heavy- duty vehicle to be 

between $50,000 and $100,000.23. Reduction of petroleum dependence is a major objective of the 

U.S. Department of Defense and it has been a significant supporter of advancing alternative 

powertrain trucks. As of 2011, initial E-Trucks capable of silent operation were available in 

Classes 3-8, primarily for worksite and urban delivery applications.

The CalHEAT Roadmap for E-Trucks, shown in Figure 21, below, identifies three technology 

stages. Currently available commercial trucks are shown as Stage 1, without accompanying 

actions. Stage 2, targeted for 2013-2017, builds off Stage 1 to improve ROI. This will be 

accomplished through improved integration of the electric driveline, optimization of system 

design to reduce use of expensive components such as copper connectors and wiring,

development of standards for battery packs in multiple sizes, and fast charging. Stage 2 

assumes a $450/kW-hr battery pack cost. An additional objective for Stage 2 is expansion of 

applications into drayage trucks. Related actions in Stage 2 include deployment incentives to 

help reduce projected ROI to five years; pre-commercial demonstrations of Stage 2 E-Trucks;

development of energy storage standards for pack-level interfaces through SAE, IEEE, or 

regulations; a study on best applications for fast charging; and a pilot demonstration of a Smart 

Charging System.

Stage 3 technology goals, targeted for 2018-2020, increase performance to a range of 150 miles

and reduce cost for the battery pack to $350/kW-hr. Technical characteristics for Stage 3 include 

larger rapid charging energy storage systems capable of storing greater than 20kW, and electric 

driveline cost reduction, which is expected to allow an option for cost-effective use of smaller 

batteries. Another technical objective is development of a secondary market for batteries.

 

23 California Energy Commission, 2009 Integrated Energy Policy Report, December 2009, 

http://www.energy.ca.gov/2009_energypolicy/index.html
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Related Stage 3 actions include pre-commercial demonstrations of Stage 3 E-Trucks, with longer 

ranges and fast charging, and deployment incentives for Stage 3 E-Trucks. 

Figure 21: E-Truck Technology and Action Roadmap 

Three stages of development have been defined for E-Trucks. Stage 1 defines technology available in 

2012. Stage 2, with development from 2013 to 2015 and deployment continuing through 2017, targets 

improved ROI through cost reduction and greater integration, along with standardization of energy 

storage, and smart charging systems. Stage 3 developments begin in 2015, working toward greater 

energy storage capacity, longer ranges, and fast charging for E-Trucks late in the decade.

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Electrified Power Take-off

A portion of work truck emissions come from the engine powering worksite equipment, such as 

a boom, tools, or other accessories not linked to the truck’s propulsion system. Use of power 

take-off systems to power these tools with electricity instead of liquid fuel when the engine is 

not running can significantly reduce emissions and fuel consumption.

The Roadmap defines two stages of development for Electrified Power Take-off, shown in 

Figure 22, page 40. Stage 1 defines existing technology, which include Class 4-5 trouble trucks 

and Class 6-7 line trucks with battery-electric storage for boom operation and the ability to 

provide AC and heating when the engine is off. The Roadmap action for Stage 1 is continuation 

of deployment incentives currently in place.

Stage 2 calls for weight reduction and lower system cost to support a 5-year ROI, integration of 

fast charging for trouble trucks, commonality across boom manufacturers’ products, and 

electric operation of on-board AC and heating systems, including fans and ducts, to eliminate 

the need for duplicate systems for engine-off operation. Additional performance improvements 

may include potential for export power and niche crane applications. Stage 2 actions include 

pre-commercial demonstrations and deployment incentives.
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Figure 22: Electrified Power Take-off Technology and Action Roadmap 

Electrified Power Take-off provides a battery system to power trouble trucks, and the booms of line trucks 

when the engine is off, to reduce the need for the engine to run only to power worksite activities. Stage 1 

covers existing technology, for which deployment incentives are already in place. Stage 2 will work 

toward a faster ROI, integration of fast charging in trouble trucks, operation of the chassis maker’s HVAC 

to eliminate duplicate systems, the potential for export power, and additional niche crane applications.

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Plug-in Hybrids

Plug-in hybrids are similar to regular hybrid electric trucks, but have the ability to recharge 

using external electric power, and typically feature a larger battery pack and powertrain system 

that potentially allow some amount of operation in electric-only mode. This can vary from the 

ability to “creep” while waiting in a line, to driving considerable distances in electric mode. 

Outside of these situations, the larger battery pack can allow the hybrid powertrain to maximize 

driving efficiency through capture of more braking energy and greater use of electricity to offset 

combustion fuels.

The CalHEAT Roadmap identifies two stages for Plug-in Hybrid Electric Technology, as shown 

in Figure 23, page 42. The economic goal for Stage 1, from 2010 through 2015, is lifetime 

payback of the incremental cost of the vehicle, compared to a conventional truck, through 

reduced fuel costs. Stage 1 performance goals include a 50% decrease in petroleum 

consumption, demonstration of zero-emission driving capability, noise reduction, and reduced 

use of conventional powertrain idle at work sites, increasing productivity, reducing emissions 

and fuel consumption, and allowing expanded hours of operation.

Stage 1 technical characteristics include incorporation of the required elements from Stage 2 

HEVs, with features such as engine off at idle, electric accessories, improved integration, and 

lighter weight, as shown in Figure 19: Hybrid Electric Technology and Action Roadmap, page 

33. Additionally, larger, cost-effective motors, and CA-compliant on-board diagnostics are

specified. The first targeted application is utility trucks; a second application in drayage has 

been identified for dual-mode use with range-extenders, which may also support a pathway for 

zero-emissions goods movement. Stage 1 actions include pre-commercial demonstration of 

goods movement drayage trucks, a plug-in hybrid utility work truck (already planned by the 

U.S. DOE), pre-commercial demonstrations of Class 2B and 3 trucks, a study to identify 

appropriate markets and applications for PHETs, and deployment incentives for the first 500 

trucks when Stage 1 PHETs are commercially available.

Stage 2 PHET, 2016 to 2020, has an economic goal of a five-to-eight-year ROI, with performance 

goals including the ability to export power, greater than 50% petroleum reduction compared to 

conventional combustion engine vehicles, and a zero-emission driving variant available.

Technical characteristics may include improved integration and HEV plug-in optimization, 

lower costs, improved range, cost-effective electric accessories, and larger, more cost-effective

electric motors. Stage 2 PHETs are expected to be commercially available in Class 2B and 3 from 

auto makers during the last half of the decade.

Stage 2 actions include a study to develop an economic model that captures externalities for a 

ZEV Corridor and deployment incentives for Stage 2 PHET drayage trucks.
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Figure 23: Plug-in Hybrid Technology and Action Roadmap

Plug-in electric hybrids have the potential to reduce petroleum use by 50% or more, and have application 

in short-range utility trucks and in drayage. Two stages of development have been defined for PHET, with 

Stage 1, 2010 through 2015, including pre-commercial and pilot demonstrations of goods movement 

drayage trucks, utility work trucks and Class 2b-3 trucks. A study is recommended to identify appropriate 

markets and applications for PHETs, with cumulative deployment incentives of $3,000,000 for the first 

500 Stage 1 PHETs when they become commercially available. Stage 2, 2015 to 2020, targets improved 

ROI through cost reduction and greater integration, and improved performance with longer ranges.

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Electrified Corridor

Various strategies have been investigated to reduce traffic congestion and related fuel 

consumption24. Intelligent vehicle technologies can take a vehicle’s position into account, along 

with data about the roads, traffic, and more, to alter routes, speeds, and in the case of hybrids, 

adjust the amount of battery power being used versus the engine. Among the more advanced 

and complicated strategies to implement are dedicated truck corridors or lanes, where trucks 

can save fuel and reduce emissions by being kept separate from passenger car traffic. These 

corridors have the potential to provide power for electrification, further increasing their 

benefits. Bus lanes have demonstrated higher average travel speeds which, particularly in urban 

areas, have the potential to significantly increase fuel efficiency for trucks.

The Roadmap for Electrified Corridors, shown in Figure 24, below, identifies areas of 

development related to external electric power for power pickup devices in on-road yard 

hostlers and electrified corridors in Stage 1, and integration of a power pickup device into dualmode hybrids and range-extended drayage trucks in Stage 2.

In Stage 1, the technology goal is to integrate a power pickup device into electric on-road yard 

hostlers. The addition of the electric power pickup device on an electric truck is intended to

allow the truck to operate using electricity with zero emissions along the corridor.

Related Stage 1 actions involve a corridor study on various roadway power systems and efforts 

to garner regional and statewide consensus on a standard for a power pickup device.

Additionally, a pre-commercial demonstration of road connections for on-road yard hostlers is 

identified in the Roadmap, along with deployment incentives to outfit electric trucks with the 

pickup device. The trucks will be required to operate in accordance with guidelines established 

under SCAQMD investments for ZEV Corridors near dock rail facilities. 

In Stage 2, efforts to integrate power pickup devices into electric vehicles will expand into dualmode hybrids and range-extended drayage trucks. Actions identified include pre-commercial 

demonstrations and deployment incentives to operate trucks in accordance with SCAQMD in 

ZEV Corridors on the CA47/103/I-710 and CA 60.

 

24National Academy of Sciences report, Technologies and Approaches to Reducing the Fuel Consumption of Medium- and 

Heavy-Duty Vehicles, August 2010, Figure 4-1
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Figure 24: Electrified Corridor Technology and Action Roadmap

The Roadmap for Electrified Corridors involves technology developments and related actions to support 

integration of electric power pickup devices into on-road electric yard hostlers, and a research study on 

roadway power systems to support development of a standard power system for a power pickup device. 

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Alternative Fuel Hybrids

Low-carbon alternative fuels including biodiesel and natural gas (NG) can offer significant 

carbon savings, even when used in an otherwise fairly conventional vehicle. There is further

potential for carbon reduction through use of renewable natural gas generated from agricultural 

feedstocks, wastewater treatment plants, and biowaste. 

The combination of a hybrid powertrain that reduces fuel consumption with an alternative fuel 

that cuts carbon per unit of fuel creates a multiplier effect and generates much less carbon 

overall.

Hybrid drive trains in certain applications are estimated to have as much as a 50% 

improvement compared to a standard diesel unit. Currently, there are hybrid-alternative fuel 

vehicles available for demonstration and commercial operation (primarily bio-diesel hybrids

and NG hybrid buses and refuse vehicles), but the weight, cost, and complexity of these systems 

has prevented their greater adoption. Further information will be available in a companion 

CalHEAT report, Barriers and Opportunities in Alternatively Fueled Hybrids25.

Three stages in the Roadmap have been defined for Alternative Fuel Hybrids, as shown in

Figure 25, page 46. Stage 1, 2012-2013, focuses on advances in B5 to B20 biodiesel hybrid trucks 

and buses (which use fuel containing 5% and 20% biodiesel, respectively) to achieve 22 -38% 

CO2e reduction, along with a significant petroleum reduction. The Stage 1 action is to encourage

a broader selection of B20-certified engines through an outreach effort to the industry. 

In Stage 2, the focus is on NG hybrid trucks from 2013 through 2017, with an economic goal of a 

three-to-five-year payback. This ROI is based on a combination of fuel savings and productivity 

gains of more stops per hour for refuse trucks enabled by hybrid technology with faster 

acceleration. These trucks also realize maintenance savings from a reduction in brake 

replacement. Performance goals include a 27-54% reduction in CO2, 100% petroleum reduction,

and increased low-speed torque in hybrid systems to compensate for lower-torque NG engines.

Technical characteristics may include right-sized NG tanks and battery or hydraulic storage for 

a NG hybrid refuse truck, and achieving a pre-commercial range-extended HEV drayage truck 

with high electrification of accessories. Actions specified in conjunction with these technology 

goals include pilot demonstration and evaluation of NG hybrid refuse trucks, a pre-commercial 

demonstration of new platforms for NG hybrid drayage trucks meeting ZEV Corridor 

requirements, deployment incentives for 200 NG hybrid refuse trucks, and R&D for smaller, 

lighter NG tanks designed for hybrid electric trucks. 

In Stage 3, the focus remains on NG hybrid trucks from 2017 to 2020. An economic goal of a 

three-to-four-year payback for a refuse truck has been defined, combined with performance 

 

25 Dr. Lawrence Wnuk, CalHEAT, Barriers and Opportunities in Alternatively Fueled Hybrids, 

Publication number: CEC-XXX-2013-XXX.
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goals of further efficiency, durability and reliability improvements, an 80% reduction in NOx 

compared to 2010, and development of an NG range-extended drayage truck capable of 

meeting zero-emission operations for ZEV corridors. Actions corresponding to these technology 

goals include deployment incentives for 100 ZEV Corridor NG hybrid trucks, and a pilot 

demonstration of NG hybrid refuse trucks with reduced NOx emission. In addition, the 

Roadmap calls for a study to identify the potential of other alternative fuels in hybrids 

including cellulosic ethanol, methanol and dimethyl ether (DME). 

Figure 25: Alternative Fuel Hybrid Technology and Action Roadmap

The Roadmap for Alternative Fuel Hybrids, which combines the advantages of electric hybrid capability 

with low carbon fuels, focuses on biodiesel hybrids in Stage 1, 2012 to 2013. In Stages 2 and 3, 

emphasis is on natural gas hybrids with improved performance and extended range during the remainder 

of the period to 2020. A study of other alternative fuels in Stage 3 is included in the Roadmap to increase 

understanding of the potential for cellulosic ethanol, methanol and dimethyl ether as hybrid fuels. 

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Hydraulic Hybrids

Hybrids come in many forms, and have already made inroads in certain segments of the truck 

industry. The fundamental theory behind hybridization, regardless of type, is that the storage of 

energy reduces fuel consumption. Hybrids typically combine some form of internal combustion 

engine with an energy storage device and are able to recapture energy and power the vehicle or 

some of its systems with it. The energy storage system in an electric hybrid involves a battery 

pack and electric motors, while, in the case of hydraulic hybrids, it uses a hydraulic tank 

(accumulator) and hydraulic motors. The accumulator stores hydraulic pressure, typically by 

using fluids to compress a gas-filled balloon inside a pressure tank. When hydraulic power is 

needed, the pressure is released, driving a hydraulic motor. 

The second primary distinction among hybrids is the architecture. Series hybrids have drive 

wheels that are driven exclusively by the electric or hydraulic motor, and the internal 

combustion engine serves to keep the system charged, but has no direct mechanical link to the 

drive wheels. In a parallel hybrid, both the electric (hydraulic) motor and the internal 

combustion engine are linked mechanically to the drive wheel, typically through a shared 

transmission. Power split, or series-parallel hybrids use a system, like a planetary gear, to allow 

the system to adjust the power ratio coming from the ICE or the electric/hydraulic power 

source. This gives the vehicle the ability to operate from 100% electric/hydraulic power to 100% 

ICE, depending on the power needs of the vehicle.

Parallel or dual-mode hybrid architectures are used in the three stages defined in this Roadmap 

for Hydraulic Hybrids, shown in Figure 26, page 48. Stage 1 covers hydraulic hybrid refuse 

trucks with parallel hybrid architectures, commercially available in 2012. They feature an 

economic payback of five years without incentives in refuse applications. Performance 

improvements of 10-25% fuel reduction from parallel hybrid architectures have been 

demonstrated, along with a 4x to 5x improvement in brake life resulting from use of a 

regenerative brake system. The hydraulic accumulator also captures kinetic energy to increase 

torque and enable the vehicle to accelerate much faster, leading to improved productivity in 

terms of number of stops possible per day.

Stage 2 development, which begins in 2014, includes additional technological development of 

series, enhanced parallel and dual-mode, or power-split, hybrid architectures and increased fuel 

economy improvement in the 35% to 100% range, compared to conventional trucks. 

Performance characteristics in the full series architecture include no mechanical connection 

between the engine and wheels. The dual-mode series hydraulic hybrid will operate in dualmode powered by both the hydraulic system and the ICE at low speeds and switch to 

mechanical transmission at highway speeds, powered by the ICE. The parallel architecture is 

expected to improve transmission efficiency and system integration. Related actions in Stage 2 

include R&D for advanced, lightweight accumulator designs; pilot demonstrations in parcel, 

beverage delivery, buses and yard hostlers; pre-commercial demonstrations of Stage 2 hydraulic 

hybrids in refuse trucks; and deployment incentives when Stage 2 trucks are commercially 

available.
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Stage 3 technology developments call for a three-year payback without incentives, performance 

goals of 50-100% fuel economy improvement compared to conventional vehicles, significantly 

longer brake life, and the potential to build a cost-effective, high-mileage vehicle in smaller sizes 

down to Class 2b. Technical capabilities include advanced series architecture with highefficiency pump, motors and controls; advanced higher density energy storage; an integrated 

dual-mode transmission hybrid with digital hydraulic components; a free piston engine with 

series configurations; and digital pumps, motors and pump-motors that can be used for parallel 

or series architectures. Actions for Stage 3 include R&D for the free piston engine, precommercial demonstrations of digital hydraulic components and Class 2b vehicles, and 

deployment incentives for Stage 3 products in Class 2b vehicles. 

Figure 26: Hydraulic Hybrid Technology and Action Roadmap

The Hydraulic Hybrid Technology and Action Roadmap defines a series of achievable stepping stones 

to improve efficiency. Improvements in hybrid architectures are expected to increase fuel economy 

improvements from 10-25% in Stage 1 to 50-100% in Stage 3, and expand applications from primarily 

refuse trucks to multiple truck categories down to Class 2b by the end of the decade. 

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Optimized Alternative Fuel Engines 

To improve performance, reduce emissions, and optimize the efficiency of engines using 

alternative fuels, various technologies have been investigated. While engines that burn natural 

gas and other alternative fuels can be cleaner than conventional diesel engines, reduce 

emissions of GHGs, and contribute to mandated goals to reduce petroleum use, the initial 

spark-ignited engines developed to burn NG have been less efficient and provide lower torque 

than diesel engines. To offset this deficiency, high pressure direct injection (HPDI) is one 

approach that has been developed to enable NG-burning engines to approach diesel efficiency 

and torque.

Other beneficial technologies to achieve significantly lower emissions and greater power using 

natural gas include alternative combustion modes such as homogenous charge compression 

ignition (HCCI). HCCI has desirable characteristics, such as low engine-out emissions combined 

with good fuel consumption, but can be difficult to control across all engine loads and in 

transient operation. HCCI helps reduce both NOx and particulate matter (PM) emissions, 

although like other alternative combustion modes, it typically achieves lower thermal efficiency 

than conventional diesel combustion. However, conventional diesel combustion suffers thermal 

efficiency degradation at low engine-out NOx levels, so the alternative combustion modes 

become more attractive as allowable NOx levels decrease during the forecast period.

To help achieve the mandated reductions in NOx, PM and petroleum use, the CalHEAT 

Roadmap for Optimized Alternative Fuel Engines, shown in Figure 27, page 50, focuses on both

performance improvements to approach conventional diesel engine efficiency and techniques to 

reduce emissions. Three Stages have been defined for NG engine optimization in the Roadmap.

Research to adapt ethanol-optimized engine technologies for use in Class 2b-3 trucks, to enable 

them to burn fuel with a higher percentage of biofuel, is also included as one of the Roadmap 

actions.

Stage 1 involves deployment support for recently developed NG-burning engines featuring 

HPDI with a diesel pilot for greater efficiency and improved torque, and stoichiometric sparkignited cooled Exhaust Gas Recirculation (EGR). Stage 2 involves performance and efficiency 

improvements; less costly, lighter, and more compact storage tanks; and use of variable valve 

actuation with cylinder deactivation. Targeted for development in 2012-2014, with deployment 

following from 2014-2017, Stage 2 will also involve expansion of optimized NG engines into a 

wider range of applications, including Classes 2b and 3-8, with a greater range of engine size 

options. Actions in the Roadmap to support these advances include R&D projects to develop 

additional engine sizes and less costly heavy-heavy duty 1.5 liter engines, plus pre-commercial 

and pilot demos.

Stage 3 performance goals call for decreased NOx emissions to 0.02g/bhp-h, a reduction of 90% 

from 2008 levels, with efficiency approaching that of conventional diesel engines. Technological 

improvements may include further downsizing with improved turbocharging, optimized 

exhaust heat recovery, homogenous charge compression ignition, a camless engine and better 
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methane catalysts. Related actions include R&D for advanced engine efficiencies and improved 

methane catalysts, and pre-commercial demonstration of decreased NOx emissions.

Figure 27: Optimized Alternative Fuel Engine Technology and Action Roadmap

The three stages defined in the CalHEAT Roadmap for Alternative Fuel Engine Optimization focus 

primarily on natural gas-burning engines to achieve performance improvements that increase torque and 

engine efficiency to levels approaching that of conventional diesel engines, while incorporating advanced 

emission reduction techniques such as HCCI, improved methane catalysts and optimized exhaust heat 

recovery to achieve very low NOx emissions. Stage 3 also calls for R&D into ethanol-optimized engines 

for use in Class 2b-3 trucks.

California Hybrid, Efficient and Advanced Truck Research Center
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Waste Heat Recovery

Recovering waste heat, through the use of thermoelectric devices, low-grade energy recovery 

devices such as those using the Rankine cycle, small turbines or other techniques, allows a 

portion of the energy normally wasted by the engine to be converted back into useful energy. If 

the thermal energy is recaptured and used to charge batteries, run accessories, or perform 

similar tasks, overall vehicle efficiency can be dramatically improved. Captured and stored heat 

can also be used in conjunction with catalytic converters to ensure complete combustion and 

fewer emissions, and possibly reduce the size and cost of after-treatment systems.

An energy audit of a typical diesel engine in a Class 8 line haul truck26 revealed that just 42% of 

the fuel energy consumed actually goes to perform useful work such as vehicle propulsion. This 

42% is consumed by drivetrain losses, rolling resistance, aerodynamic drag, and auxiliary loads 

such as the alternator, air compressor, and power steering pump. Energy lost as engine heat 

accounts for 26% of the fuel consumed and exhaust heat accounts for another 24%. Finding 

ways to recapture the waste heat is an important part of reducing vehicle fuel consumption.

Turbocompound systems add a second exhaust turbine downstream of the engine’s primary 

turbocharger to extract additional energy from the exhaust flow. Rather than compressing the 

intake air like the primary turbo, the turbocompound exhaust turbine converts a portion of the 

energy in the exhaust flow to useful energy. This conversion can provide either mechanical 

(rotational) or electrical energy back to the vehicle’s powertrain. This regenerated energy lowers 

the fuel-derived energy demand on the engine, thus reducing the fuel consumption. In a 

mechanical turbocompound system, the exhaust turbine is connected to the engine’s crankshaft 

through gearing and a fluid coupling to regenerate a portion of the exhaust flow energy back 

into the powertrain. In addition, the brake power output of the engine is also increased with 

mechanical turbocompounding, thus creating the potential for engine downsizing that can 

further reduce fuel consumption in the vehicle. An increase in power output of roughly 10% is 

not unusual. This would correspond to a roughly 5% decrease in fuel consumption. The fuel 

consumption is smaller than the power increase due to higher pumping losses from the higher 

exhaust backpressure27.

A turbocompound system provides the greatest benefit at full load. The improvement is much 

less – or even zero – at light loads. Thus, these systems are best suited for vehicles that consume 

most of their fuel at fairly high loads. Examples include line-haul trucks and vocation vehicles 

such as refuse trucks.

Some of the advantages of mechanical turbocompound systems include high power density 

(more power for a given displacement) and reduced fuel consumption in highly-loaded vehicle 

applications. A potential reduction in fuel consumption of 3% can be achieved in long-haul 

 

26 National Academy of Sciences, p. 5-60.

27 Anthony Grezler, Volvo Powertrain Corporation, Diesel Turbo-compound Technology, ICCT/NESCCAF Workshop 

presentation, February 20, 2008, slide 5.
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applications, although there can be a minimal or negative impact with light loads. Since exhaust 

manifold pressure is increased above intake manifold pressure, higher EGR flow can be 

achieved more easily to facilitate low NOx emissions.

Some of the challenges facing broad acceptance of turbocompounding are that the gear train, 

fluid coupling, and power turbine add weight, complexity (reliability concern), and cost.28

Exhaust energy decreases with cooled EGR due to energy extracted into the cooling system, 

resulting in less energy available to the power turbine. Space requirements further constrain 

packaging of EGR and turbochargers and add complexity in design, control, and service.

Additional cooling of exhaust reduces the effectiveness of exhaust after treatment systems.

These systems may require more active regeneration for the particulate filter, and may reduce

the time when NOx systems are effective, including those based on Low NOx Ammonia (LNA) 

applications, selective catalytic reduction (SCR), or Lean NOx Catalysts (LNC).

In the CalHEAT Roadmap for Waste Heat Recovery, shown in Figure 28, page 53, Stage 1 

performance goals were identified for turbocompounding using mechanical recovery systems.

At least two engine manufacturers have mechanical turbocompound systems in production 

today, so no actions were included for Stage 1. Stage 2 identifies technology improvements 

projected for 2015-2019, which will include blowers for vocational trucks, organic Rankine

cycles, electric turbocompounding for OTR trucks, thermoelectric systems, and both electrical 

and mechanical recovery. An increase in electrical waste heat recovery is projected going 

forward. Two accompanying actions for Stage 2 include R&D to apply thermoelectric designs in 

medium- and heavy-duty trucks, and pilot and pre-commercial demonstrations of waste heat 

recovery in vocational and OTR trucks. 

 

28 Anthony Grezler, Volvo Powertrain Corporation, Diesel Turbo-compound Technology, 

ICCT/NESCCAF Workshop presentation, February 20, 2008, slide 6.
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Figure 28: Waste Heat Recovery Technology and Action Roadmap

Waste Heat Recovery offers the potential to recapture engine and exhaust heat to help power the vehicle. 

Mechanical turbocompounding systems are currently in production. CalHEAT Roadmap actions for this 

technology strategy begin in Stage 2, projected for 2015-2019, and are related to R&D and pilot and precommercial demonstrations of thermoelectric waste heat recovery. 

California Hybrid, Efficient and Advanced Truck Research Center
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Engine Optimization

Increasing efficiency and decreasing energy losses in truck engines are critical elements in the 

effort to reduce truck fleet fuel consumption. Optimized engines are one of the technology 

strategies to achieve this. Roughly 60% of the chemical energy of the fuel used in a truck diesel 

engine is lost in the engine, through heat losses or low combustion efficiency29. Gasoline engines 

are even less efficient at converting the fuel they consume into usable power to operate the 

vehicle.

In 2006, the 21st Century Truck Partnership30 (21CTP) outlined goals to increase the energy 

efficiency of the engine system for class 7-8 trucks from 42% to 50% by 2010 and 55% by 2013.

To build upon the energy efficiency improvements from the 21CTP, in January 2010, the DOE 

awarded $115 million for three projects under the Supertruck program. The Supertruck projects

are intended to improve fuel efficiency of heavy-duty Class 8 long-haul trucks and will 

incorporate a wide range of technologies resulting from the 21CTP program over the past 

decade31.

The CalHEAT Roadmap defines three technology stages for Engine Optimization, as shown in

Figure 29, page 53. In Stage 1, 2012 to 2013, the technology-related goals from existing industry 

projects have been incorporated into the Roadmap, without accompanying actions.

Performance goals, driven by National Highway Traffic Safety Administration (NHTSA) 

legislation, are to achieve a 47% brake thermal efficiency (BTE) improvement, on a level road at 

65 miles per hour, compared to the baseline conventional diesel vehicles and engines.

Technologies used to achieve this include engine boosting, downspeeding to 1000-1200 RPM 

(which requires faster transmission gear shifting), and other technologies required to meet 

Federal EPA/NHTSA Phase 1 rules for commercial vehicles.

The Stage 2 Engine Optimization Roadmap, 2014 to 2017, identifies a performance goal of 50% 

BTE corresponding to the DOE Supertruck project developments. Actions for Stage 2 include a 

pilot demonstration of a 50% BTE Class 8 truck, incorporating all needed technologies to 

achieve up to a 1.5 truck efficiency improvement over the baseline vehicle and engine 

performance.

Stage 3 builds upon Stage 2, and targets a 55% BTE DOE Supertruck, incorporating advanced 

technologies that may lead to a 200% more fuel efficient Class 8 OTR truck, with significant 

NOx reduction and advanced exhaust heat recovery advances described in the Waste Heat 

Recovery section, above. Actions for Stage 3 include R&D to promote NOx reduction 

technologies, pilot demonstration of a 55% BTE Class 8 truck with 200% fuel efficiency 

improvement, and pilot demonstration of an OTR truck with three to ten times lower NOx.

 

29 National Academy of Sciences, Figure 4-1.

30 National Academy of Sciences, p. 55-56.

31 Committee to Review the 21st Century Truck Partnership, Phase 2, National Research Council. SuperTruck Program. Review 

of the 21st Century Truck Partnership, Second Report. Washington, DC: The National Academies Press, 2012.
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Figure 29: Engine Optimization Technology and Action Roadmap 

The CalHEAT Roadmap defines three stages for Engine Optimization, starting with technologies already 

defined in the DOE Supertruck program to achieve 47% Baseline Efficiency in 2012 to 2013. Stages 2 

and 3 leverage the Supertruck program for California, and include performance goals of 50% BTE in 

Stage 2 and 55% in Stage 3. Stage 2 actions in this Roadmap for California include a pilot demonstration 

of the 50% BTE Class 8 Truck and deployment incentives likely to begin in 2016 for early fleet 

deployments for the first 200 OTR trucks. Stage 3 actions include R&D programs for NOx reduction and 

pilot demonstrations of both a 55% BTE Class 8 OTR truck and an OTR truck with 3x to 10x lower NOx. 

California Hybrid, Efficient and Advanced Truck Research Center
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Alternative Power Plants and Combustion Cycles

Other CalHEAT research into opportunities to reduce petroleum consumption and GHG 

emission included fuel cells, alternative engine architectures and combustion technologies, 

along with turbines used as generators for electric drivelines. These technologies enable 

development of zero-emission and near-zero-emission vehicles. Near-zero-emission 

developments reduce NOx emissions approximately 90% from 2010 emissions for trucks.

The Alternative Power Plant and Combustion Cycle Technology and Action Roadmap, 

shown in Figure 30, below, covers technology developments in various areas including fuel 

cells in trucks, turbines, camless engines, opposed piston and free piston engines, and 

homogenous charge compression ignition (HCCI), which is an alternative combustion 

mode.

Fuel cells are a zero-emission power source that have shown promise as premium power 

generators in the 5-10 kW range but have not yet reached the packaging size, weight, and 

cost range needed for widespread acceptance for on-board power in trucks.

As the starting point for further development, Stage 1 describes fuel cell and stationary 

turbine technology available commercially in 2012 for use in transit buses. The Federal 

Transit Authority has been supporting R&D and deployment funding for fuel cell transit 

buses, with the primary objective of reducing fuel cell cost and footprint and increasing 

reliability.

Stage 2 developments, targeted for 2015-2018, show initial deployments of fuel cells and 

turbines in trucks as range extenders, with a parallel hybrid electric driveline used in 

conjunction with the turbine. These developments are supported by Roadmap actions for 

pre-commercial and pilot demonstrations. Alternative engine technology developments 

targeted for this stage include camless, opposed piston, free piston, and HCCI engines.

Roadmap actions define R&D and pilot demonstrations, and deployment incentives for low 

NOx engines. 

Stage 3 developments define further stepping stones for each of the Stage 2 technologies, 

with goals for 2018-2020 including cost-effective fuel cells, reduced NOx levels of 

0.02g/bhp-h in turbines, commercial production of camless engines capable of burning NG 

to achieve NOx levels of 0.02g/bhp-h, and demonstrations of HCCI, opposed piston and 

free piston engines.
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Figure 30: Alternative Power Plant and Combustion Cycle Technology and Action Roadmap

The CalHEAT Roadmap for Alternative Power Plants and Combustion Cycles defines existing fuel cell 

and stationary turbine technology for electric drivelines used in transit business in Stage 1, and defines a 

path for incorporating these technologies into trucks in Stage 2. Other technologies covered in this 

Roadmap include alternative engine architectures including camless, opposed piston, free piston and 

HCCI engines as avenues to achieve low NOx emissions before 2020.

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Transmission/Driveline Improvements

The 21st Century Truck Partnership improvements in engine efficiency, discussed above in the 

Engine Optimization section, page 54, did not look at total powertrain system efficiency but 

instead focused on changes to the engine itself. A rich area identified in this Roadmap for 

additional improvement is fully-optimized powertrains, in which the entire powertrain is sized,

calibrated and operated as a unit to achieve highest system efficiency. Potential improvements 

in powertrain system efficiency are likely to be achieved through advances in engine hardware 

and calibration, emissions control systems, accessories, and transmissions. 

Two Stages have been defined for transmission and driveline improvement in this Roadmap as 

shown in Figure 31, page 59. Stage 1 covers deployment of improvements that are part of the 

DOE Supertruck program, 2012 through 2016, which have an economic goal of a one-to-twoyear payback in OTR trucks. This will be achieved through performance improvements 

resulting in a 1-2% reduction in fuel use. The technology to do so uses faster shifting 

transmissions needed to support downspeeding to 1100 RPM, and may involve use of 

Automated Manual Transmissions. The related actions are included in the Engine Optimization 

Technology and Action Roadmap, Figure 29, page 55. Stage 2 calls for a 5% reduction in fuel for 

OTR trucks, and is likely to be achieved through further downspeeding to 1000 RPM and a shift 

to Automated Manual Transmissions. Research and demonstrations for Stage 2 are scheduled 

for 2012 to 2016, with deployment from 2016 through 2020. 
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Figure 31: Transmission/Driveline Technology and Action Roadmap 

The Transmission/Driveline Roadmap focuses on improvements in powertrain system efficiency to be 

achieved through faster shifting transmissions needed to support lower RPM engines, greater powertrain 

integration and calibration, and shift to Automated Manual or Automatic Transmissions throughout the 

period to 2020. 

California Hybrid, Efficient and Advanced Truck Research Center
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CHAPTER 3:

Conclusions

With the development of this CalHEAT Research and Market Transformation Roadmap for Mediumand Heavy-Duty Trucks, CalHEAT has now nearly completed the goals established for its initial 

three years of operation. Analysis of the CalHEAT Action Plan shows that implementation of 

the 66 action items would result in a 73% reduction in CO2e by 2050, and 75% reduction in 

petroleum use, compared to projected “Business as Usual” levels without these changes. 

For CO2e, the projected reduction would be 44MMT/year in 2050, from a BAU level of 60MMT 

to 16MMT with implementation of the Roadmap action items. For comparison, the 2012 level is 

36MMT/year. 

For petroleum, the projected reduction would be 4.5 billion gallons per year in 2050 compared 

to a projected BAU use of 5.9 billion gallons, to 1.5 gallons/year. For comparison, truck-related 

2012 petroleum consumption is 3.6 billion gallons/year. These projections are based on the 

assumption of a moderate 25% adoption rate for biofuels. The “Business as Usual” projections

used for comparison assume use of existing technology and practices, adjusted for anticipated 

growth in number of vehicles and vehicle miles travelled. There is potential for significantly 

greater reductions of CO2e and petroleum with a higher adoption rate of biofuels.

Over the same period, NOx emissions are projected to decrease 73%, or 180 MT/year, from 

249,000 MT/year in 2012 to 67,000MT/year in 2050.

This transformation Roadmap for California outlines specific actions to drive down climate and 

criteria emissions and fuel use in the medium- and heavy-duty truck and goods movement 

sectors. Nineteen strategies in three pathways, as shown in Figure 32 below, were identified as 

having the potential to achieve significant energy and environmental benefits to meet State 

policy goals.
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Figure 32: Technology Pathways

Nineteen technology strategies were identified by CalHEAT as pathways

to enable reductions in carbon and criteria emissions and fuel use in 

trucks. The Electrification and Engine & Driveline Efficiency pathways 

are the focus of the 66 actions in the Roadmap. The technology 

strategies shown under Chassis, Body and Roadway Systems are 

already planned by manufacturers or transportation authorities.

California Hybrid, Efficient and Advanced Truck Research Center

The 13 technology strategies shown above, under Electrification and Engine & Driveline 

Efficiencies, were selected as the focus of the CalHEAT Roadmap. Those listed under Chassis, 

Body and Roadway Systems are receiving reasonable attention by the industry and industry 

stakeholders and as such are not a focus of the present CalHEAT Action plan. Within these 13 

strategies, 66 actions have been identified, with target dates and milestones for the period from 

2012 through 2020. Appendix B, page 65, includes a summary of the actions by technology 

strategy, followed by a numerical list with descriptions, and Appendix C, beginning on page 74, 

summarizes them by action category: Studies and Standards, Development, Pilot 

Demonstrations, Pre-Commercial Demonstrations and Deployment Support and Incentives. 

As a first step toward developing the Roadmap during this three-year project, CalHEAT 

established the CalHEAT Truck Research Center in Pasadena and recruited its Advisory

Council , Steering Committee , and Technical Advisory Group , which consist of qualified 

professionals from the truck and utility industries and a diverse range of regional, State, and 

Federal government agencies. CalHEAT also conducted Phase I research to characterize the 

California truck population by size, use, and emissions, and prepared a baseline report of 

available technology and pathways for improvement. Phase II research identified gaps along 

the pathways and barriers to progress, and developed a decision-making tool to identify the 

most efficient choices to meet the State’s goals. Phase III was the development of the Roadmap 
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that comprises this report. Additional research and demonstration projects were also conducted 

for advanced Class 8 trucks, plug-in parcel delivery trucks and alternative fuel hybrid 

technologies.

As a result of this process, CalHEAT has also become a key consensus point for industry and 

the public sector to meet and reach agreement on the key action steps and investments needed 

to transform medium- and heavy-duty trucks in the state.

Priority Actions

Critical to the implementation of these sixty-six Roadmap actions is funding. Next steps would 

be to prioritize and act on the sixty-six step action plan, initiate critical action items that relate to

more efficient drive lines in Class 8 Over-the-Road Tractors which represent a projected 40% of 

CO2e emissions from trucks in 2050, and provide technical assistance to fleets and policy makers 

in order to accelerate the adoption of clean and efficient technologies.

The process would involve development of criteria for priority ratings, along with 

implementation of the action items by catalyzing, facilitating, or administering related projects. 
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Recommendations for Next Steps

The CalHEAT Advisory Council has recommended additional research to support 

implementation and update of the roadmap. This would include updating the Roadmap and 

related model with adoption rates and an improved inventory analysis on natural gas trucks.

There is also an ongoing need to track and search for new breakthrough technologies and 

incorporate these breakthroughs into the Roadmap. 

Further research on clean and efficient driveline technologies would include more focused 

investigation of the Class 8 Truck population in the state, and within regions of the state, on 

their points of origin as well as the corridors they use, both in and out of California.

Development of a plan is recommended to leverage federal funding on advanced and clean-fuel 

buses in order to expedite the entry of these technologies in to California’s truck market.

Additional recommendations include projects and partnerships to continue development of 

advanced and efficient Class 8 Over-the-Road Trucks, as Class 8 tractors are the largest 

contributor of CO2e in the medium- and heavy-duty truck market. This activity could build off 

CALSTART’s High-Efficiency Truck Users Forum’s (HTUF) Class 8 Working Group findings to 

develop and demonstrate the following suggested projects or programs:

a. A more electrified Over-the-Road Truck 

b. Advanced and highly-efficient combustion technologies and fuel cell solutions

c. Three hundred percent greater vehicle efficiencies leveraging driveline improvements, 

engine efficiencies, and improved vehicle aerodynamics and rolling resistance

d. Technical assistance to fleets, dealers, and maintenance shops to assure a better 

understanding of early market adoption issues and provide help understanding the 

business case. Technical assistance would also be provided to state and regional agencies to 

support development of future investments and policies, and to industry suppliers in order 

to help them prioritize and understand the technologies and need for development and 

innovation.

Strategies related to clean and efficient drivelines in Class 8 OTR trucks could address as much 

as 8 million annual metric tons of CO2e by 2050. Recommendations include more specific 

research to identify the major state and regional corridors, the key destinations of the out-ofstate registered vehicles, and the in-state registered usage of Class 8 OTR trucks. Additional 

research could focus on the market barriers and benefits from zero-emission truck corridors 

extending from the Ports of Los Angeles and Long Beach through the Central Valley to the 

Ports of Stockton and Oakland. 

Additional work with industry stakeholders could identify ongoing near-zero-emissions 

technologies and help establish near-term voluntary standards. These standards are critical to 

achieving an 85% reduction of NOx in the South Coast region.

The Advisory Council also recommends formulation of a plan to leverage large investments by 

the Federal Transit Administration in clean and efficient bus technology and expeditiously 
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transition these developments to ZEV and NZEV trucks. This plan could potentially accelerate 

the early adoption of Heavy Trucks that are ZEV and NZEV by 2 to 3 years, resulting in a more 

significant adoption rate by 2050.

Finally, next steps could also include additional research on new focus areas that could lead to 

significant reductions in carbon, criteria emissions, or fuel use that were not necessarily a focus 

of the initial CalHEAT work. These include biofuel availability and efforts to reduce the growth 

of vehicle miles travelled by California trucks. 

Research and action recommendations to increase use of renewable diesel, bio-diesel, renewable 

natural gas, and/or ethanol in heavy long distance trucks is considered critical, as use of 

renewable fuels could have a significant impact on the CO2e emissions projected by the 

roadmap for 2050, as shown in Figure 11: Biofuel Related Impact on CO2e Reduction, page 25.

Finding additional ways to reduce the projected growth of VMT in California could also have a

significant impact, as increases in VMT contribute to 40% growth in the business as usual 

projections for CO2e. The objective related to VMT research is to identify roadway systems and 

policy approaches that could reduce VMT with little or no impact on commerce. Suggested 

research projects in these areas include:

a. Biofuel Availability and Projections for Medium- and Heavy-Duty Vehicles: Update 

forecasts for potential production of renewable natural gas, renewable diesel and biodiesel. Increased availability of these biofuels could have an impact as great as 

12MMTCO2e reduction by 2050.

b. Best Policies, Technologies and Practices in Reducing Vehicle Miles Traveled (VMT):

State predictions for VMT growth are significant and can easily contribute up to 25 

million metric tons of CO2e per year by 2050. The projections are based on conventional 

technologies and regulations. There are opportunities to increase the payload per truck 

through use of double trailers, and consider use of regulations to maximize the payload 

in each truck to avoid less than full loads. Additional opportunities include platooning 

of trucks, expansion of truck corridors, and driverless vehicles.
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APPENDIX A:

Methodology and Sources 

Resources

The CalHEAT Advisory Council and Steering Committee listed on page ii of the Research and 

Market Transformation Roadmap for Medium- and Heavy-Duty Trucks (CEC-XXX-XXXX-2013)

assisted and reviewed materials developed in the Roadmap and action plan. The CalHEAT 

Technical Advisory Group listed on page iii of the Roadmap reviewed technical strategies and 

results.

Two outside consulting firms were utilized as additional resources. Ricardo plc 

(www.ricardo.com), a global engineering and innovation consultancy with expertise in the

automotive market, analyzed CO2 benefits and adoption rates for technologies. ZMassociates 

Environmental Consultants (www.zmassociates.com) calculated petroleum, CO2e, and NOx 

reductions, and assembled the report.

California Truck Inventory and Impact Study

As the first step in the development of this Roadmap, CalHEAT performed a California Truck 

Inventory and Impact Study32 to better understand the various types of trucks used in 

California, their relative populations, and how they are used. The baseline inventory, acquired 

through Polk, consisted of commercial Class 2b through Class 8 vehicles registered through the 

California Department of Motor Vehicles. Data was taken from 2009 registrations consisting of 

about 1.5 million commercial medium- and heavy-duty trucks, grouped by weight and 

application, to establish a baseline inventory, fuel use, and emissions, to be used to evaluate the

potential for efficiency and emissions improvements.

A CalHEAT-specific system of reclassifying the vehicles into six categories by a combination of 

weight and duty cycles was devised. In order to do this correctly, a Technical Advisory Group

was created consisting of nationally-recognized medium- and heavy-duty truck associations, 

manufacturers, and experts. After the six Cal HEAT truck categories were defined, a logic table 

was developed to automatically reclassify the 1.5 million trucks into breakout populations for 

each of the categories.

 

32 Jennings, Geoff, and Brotherton, Tom. (CalHEAT). June, 2012. 
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The next step was to create a baseline emissions inventory, broken out by the six truck 

categories. This was done by performing secondary research on the average VMT, fuel 

consumption, and emissions per mile for each of the truck categories to define the average fuel 

used and NOx and CO2e emission levels. These averages were then multiplied by the vehicle 

populations derived in the truck population inventory to develop baseline fuel consumption,

CO2e and NOx levels as shown in Figure 3: Truck CO2e, Average Vehicle Miles Traveled and 

Population by Truck Category, page 12, and Figure 4: Relative NOx by Truck Category, page 13.

Vehicle Technologies

Vehicle Technology Pathways

Technology strategies were initially proposed for the action plan based on CALSTART’s 

experience on its High-Efficiency Truck Users Forum (HTUF) Program. The initial advisory 

council meetings focused on developing consensus on which technology strategies to pursue in 

the Roadmap and action plan.

Gap Analysis

This phase of the Roadmap focused on research to identify gaps along technology pathways, 

the status of market penetration and barriers that may be holding back progress. Initial 

interviews were established with a variety of technology advisory committee members and

with Ricardo automotive consultants. Ricardo was selected as a consultant to CalHEAT for the 

purpose of vetting the industry feedback received.

Initially CalHEAT was able to determine near term gaps and in what timeframe a given 

technology strategy may be able to have some significant impact on the CO2 profile for 

California, classified by each of the six truck categories. These are illustrated under Table 5:

Promising Technology Pathways by Truck Category, page 19, using Harvey balls to identify 

technologies that are expected to make a significant reduction in CO2 before 2020, vs. those not 

expected to be implemented until after 2020, or not make a significant contribution in CO2

reduction at all. 

Petroleum, CO2e, and NOx Reduction Analysis

To project likely CO2e, NOx, and petroleum reductions, a look-up table and model was 

developed for a near term generation and a future long term generation of each truck category,

and correlated to the 13 technology strategies.

A straw man action plan and Roadmap for the generations of each technology was developed, 

culminating in a long-term commercial product that could ultimately provide a 2-to-4 year 
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return on investment. The initial Roadmap was developed based on industry interviews and 

CALSTART knowledge of electrification technologies from the HTUF Program. A 

corresponding action plan for each technology strategy was developed providing actions along 

with their cost to culminate in a mature, cost-effective technology offering.

The set of straw man Roadmap and action plans were submitted to the full Technology 

Advisory Group for review. Nearly 90% of the Technical Advisory Group members provided 

detailed responses in their areas of expertise. Additional interviews were performed in areas 

that the CalHEAT staff considered to be incomplete, and then the Roadmap and action plan was 

generated.

The results of the Roadmap technologies combined with the model resulted in the projected 

reductions of petroleum, CO2e, and NOx, discussed in the Results section of Chapter 1, under 

Truck Fuel Use, page 13, through the Fuel-Related Reductions section, which begins on page 22.

The EMissions FACtor (EMFAC) model was used for projecting increases in vehicle populations 

and VMT. EMFAC categories were mapped to the CalHEAT categories in order to project the 

increase in each CalHEAT category. As EMFAC only provided data to 2035, the data were 

extrapolated to 2050 using the period 2020 to 2035, where it was expected effects from the 

recession would be minimal. 

Assumptions for NOx calculations discussed in the Results section and shown in Figure 12: 

Projected NOx Reductions, page 26, are that NOx emissions decrease with a decrease in fuel 

consumption due to higher efficiencies, but are not affected by use of biofuels or 

decarbonization. NOx reduction technologies will be adopted beginning in 2020. 

Adoption Analysis

The CalHEAT staff, with the assistance of Ricardo, developed a model which used the 

CalHEAT categories developed for the emissions reduction model, added unique vehicle 

technology adoption rates for each truck technology and category, and then rolled up the result 

of the CO2 reduction over time to obtain projections for 2020, 2035 and 2050. The adoption rates 

were generated by reviewing recent Class 8 Truck Adoption rates provided by the North 

American Council for Freight Efficiency (NACFE) and some general automotive adoption rate 

curves. 

The model was ultimately used to generate the adoption curves shown in Category Figure 13: 

Technology Adoption by Truck Category , page 27, and Figure 14: Technology Adoption all 

Truck Categories, page 28. 
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APPENDIX B:

Sixty-six Actions by Technology Strategy

In this Appendix, the 66 Roadmap actions to reduce petroleum, CO2e, and NOx, or improve 

truck efficiency are grouped by technology strategy and identified by action category, such as

studies and standards through deployment, in Figure 33, page 69. A numerical list with 

descriptions of each action follows in Table 6, page 70. 
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Figure 33: Sixty-Six Actions by Technology Strategy

The 66 actions to reduce petroleum, CO2e, and NOx, or improve truck 

efficiency are grouped by technology strategy and identified by action 

category, from studies and standards through deployment. Refer to Table 

6, below, for a numerical list, timeline and description. 

California Hybrid, Efficient and Advanced Truck Research Center

Studies and Standards

Development

Pilot Demo

Pre-Commercial Demos

49B Deployment Support 

and Incentives

1 5

Alternative 

Power Plants & 

Combustion 

Cycles

1 6

1 7

2 7

4 8

5 7

6 5

 Engine 

Optimization

1 4

4 4 5 8

6 6

6 1

Waste Heat 

Recovery

1 3

2 6

4 7

5 5

3 9

Hydraulic

 Hybrid

1 0 4 1

1 9

3 5 4 6

6 0

Optimized AF 

Engine

1 1 2 4

1 2

2 0

3 6

3 8 5 9

Electric Corridor 

5

3 3 5 4

5 6 6 3

AF Hybrid 

6 4 0

9

2 5 5 3

3 4

5 2 6 4

Electric Power 

Take-off

2 9

5 0

Plug-in Hybrids

4 2 2

3 0

3 1

3 2

5 1

Electrified 

Auxiliaries 

2

7

8

E-Trucks 

3A & B

1 8

2 8

4 5

49A

2020

4 3

2019

Hybrid- Electric 

1

2 3

4 2

2 1

3 7

2013 2014 2015 2016 2017 2018

6 2
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70

Table 6: Sixty-six Actions in CalHEAT Roadmap

 # Technology 

Strategy

Action Category Year(s) Description

1 Hybrid Electric Studies and 

Standards

2013 Industry assistance to overcome California OBD issues.

2 Electrified 

Auxiliaries

Studies and 

Standards

2013 Formulate and expedite adoption of standards such as voltage variants 

and J1939 signal controls.

3a

3b

E-Trucks Studies and 

Standards

2013

2013

Develop energy storage standards (pack level interfaces) to encourage 

greater selection and competition through SAE or IEEE or regulation.

Study best Applications for fast charging for increase truck and battery 

utilization

4 Plug-in Hybrids Studies and 

Standards

2013 Identify appropriate markets and truck platforms that have a potential 

business case.

5 Electric Corridor Studies and 

Standards

2013 Assess various roadway power systems and garner regional and 

statewide consensus on a standard for a pickup device.

6 AF Hybrid Studies and 

Standards

2013 Perform outreach to encourage an increase and broader selection of B20-

certified engines.

7 Electrified 

Auxiliaries

Development 2013-14 Develop more purposely-designed electronics (but ideally shared 

architecture, DC-DC converters, auxiliary drives, power steering, 

pumps) that can be integrated into vehicles.

8 Electrified 

Auxiliaries

Development 2013-14 Develop a power distribution box/suppliers to allow for commonality 

across OEMs an enabler for cost reduction.

9 AF Hybrid Development 2013-14 Develop smaller & lighter CNG tanks designed for HE trucks.

10 Hydraulic Hybrid Development 2013-14 Develop a light-weight advanced accumulators.

11 Optimized AF 

Engine

Development 2013 Develop additional smaller engine sizes for efficiency and performance 

improvements (especially low-end torque).

12 Optimized AF 

Engine

Development 2013 Develop lower cost HHD NG solutions (Heavy - Heavy 1.5 liter engine).

13 Waste Heat 

Recovery

Development 2013-14 Develop/apply thermoelectric designs to M-HD applications.

14 Engine 

Optimization

Development 2013-14 Develop engines and systems to provide 50% reduced NOx.

15 Alt Power Plants 

and Combustion 

Cycles

Development 2013 FTA providing development funding for fuel cell transit buses, with the 

primary objective of reducing fuel cell cost, reducing footprint, 

increasing reliability.

16 Alt Power Plants 

and Combustion 

Cycles

Development 2013-14 Develop one or two new advanced engine designs such as camless, 

opposed piston or HCCI.

17 Alt Power Plants 

and Combustion 

Cycles

Development 2013-14 Develop a purposely-designed turbine for vehicles.

18 E-Trucks Pilot 

Demonstrations

2013-14 Pilot demos of smart charging systems.

19 Hydraulic Hybrid Pilot 

Demonstrations

2013-14 Pilot demos of stage 2 in Parcel, Beverage Delivery, Buses and Yard 

Hostlers.

20 Optimized AF 

Engine

Pilot 

Demonstrations

2013-14 Pilot demos of special CNG tanks with newer lighter materials.

21 Hybrid Electric Pre-Commercial 

Demonstrations

2013-14 Demos of next stage 2 hybrid drivelines incorporating improved design 

and integration and a preference for ARB OBD compliance, as well as 

electrified auxiliaries

22 Plug-in Hybrids Studies and 

Standards

2014 Formulate a drayage truck economic model that captures externalities 

for ZEV Corridor.

Sixty-six actions identified in the CalHEAT Research & Market Transformation Roadmap for Medium- and HeavyDuty Trucks are listed above by action number, technology strategy, action category, and years in which action is 

planned, with a description. The table continues on the next two pages.
Draft Publication Rev # 7 Dated 6-14-2013

71

California Hybrid, Efficient and Advanced Truck Research Center
Draft Publication Rev # 7 Dated 6-14-2013

72

Table 6: Sixty-six Actions in CalHEAT Roadmap (Continued, page 2 of 3)

# Technology Strategy Action Category Year(s) Description

23 Hybrid Electric Development 2014 -15 Develop prototypes for optimized and downsized engines to be used in 

hybrid systems.

24 Optimized AF Engine Development 2014-15 Develop advanced engine efficiency strategies and improved methane 

catalysts.

25 AF Hybrid Pilot Demonstrations 2014-15 Pilot demos to evaluate/benchmark various NG/hybrid refuse trucks.

26 Waste Heat 

Recovery

Pilot Demonstrations 2014-15 Pilot demos of waste heat recovery in a vocational and line-haul truck.

27 Alt Power Plants and 

Combustion Cycles

Pilot Demonstrations 2014-

2016

Pilot demos of camless, opposed piston , free piston or HCCI engines in 

trucks.

28 E-Trucks Pre-Commercial 

Demonstrations

2014-15 Demos of improved integration, lower-cost stage 2 E-Trucks for ZEV 

Corridor applications & goods movement.

29 Electric Power TakeoffPre-Commercial 

Demonstrations

2014-15 Demos of next-gen lower-cost state 2 systems.

30 Plug-in Hybrids Pre-Commercial 

Demonstrations

2014-15 Demos of good movement and drayage trucks.

31 Plug-in Hybrids Pre-Commercial 

Demonstrations

2014-15 DOE SCAQMD utility trucks (ARRA Funded).

32 Plug-in Hybrids Pre-Commercial 

Demonstrations

2014-15 Demos of stage 1 in Class 2b trucks.

33 Electric Corridor Pre-Commercial 

Demonstrations

2014-15 Demos of preferred on-road connection device for electric or PHET 

yard hostlers.

34 AF Hybrid Pre-Commercial 

Demonstrations

2014-15 Demos of new platforms of NG/hybrid drayage truck meeting ZEV 

Corridor requirements.

35 Hydraulic Hybrid Pre-Commercial 

Demonstrations

2014 Demos of series, enhanced parallel and/or dual-mode (power split) 

stage 2 hybrids in refuse trucks.

36 Optimized AF Engine Pre-Commercial 

Demonstrations

2014-15 Demos of lower engine sizes and new lower cost 15 liter engines to 

broaden number of platforms.

37 Hybrid Electric Deployment Support 

and Incentives

2014 Support for 1000 stage 2 hybrids when they become commercially 

available.

38 Hydraulic Hybrid Deployment Support 

and Incentives

2014-15 Support for the first 100 stage 2 vehicles when they become 

commercially available.

39 Optimized AF Engine Deployment 

Incentives

2014-15 Support for 1000 stage 2 trucks.

40 AF Hybrid Studies and 

Standards

2015 Understand potential for cellulosic ethanol, methanol and DME as 

hybrid and optimized engine fuels.

41 Hydraulic Hybrid Development 2015 Free Piston engine development.

42 Hybrid Electric Pilot Demonstrations 2015-16 Pilot demos of optimized and downsized engine/s to be used in hybrid 

systems.

43 Electrified Auxiliaries Pilot Demonstrations 2015-16 Pilot demos for validation of electrified auxiliaries in Class 7-8 (nonhybrid) tractors, line-haul trucks and other trucks.

44 Engine Optimization Pilot Demonstrations 2015-16 Pilot demos of 50% brake thermal efficiency engines leveraging DOE 

program and also incorporating all relevant technologies to achieve up 

to 1.5x truck efficiency improvement.

Actions 23 through 44 in the CalHEAT Research and Market Transformation Roadmap for Medium- and 

Heavy-Duty Trucks are listed above by action number, technology strategy, action category, and years in 

which the action is planned, with a description. The table continues on the next page.

California Hybrid, Efficient and Advanced Truck Research Center
Draft Publication Rev # 7 Dated 6-14-2013

73

Table 6: Sixty-six Actions in CalHEAT Roadmap (Continued, page 3 of 3)

 # Technology Strategy Action Category Year(s) Description

45 E-Trucks Pre-Commercial 

Demonstrations

2015-16 Demos of significantly lower cost stage 3 E-Trucks, including longer 

ranges & fast charging.

46 Hydraulic Hybrid Pre-Commercial 

Demonstrations

2015-16 Demos of ultra-high efficiency stage 3 technology using digital 

hydraulic components into a Class 2b and one other larger truck 

platform.

47 Waste Heat 

Recovery

Pre-Commercial 

Demonstrations

2015-

2017

Demos of waste heat recovery in vocational and line-haul trucks.

48 Alt Power Plants and 

Combustion Cycles

Pre-Commercial 

Demonstrations

2015-

2017

Demos of camless, opposed Piston, free piston or HCCI engines in 

trucks.

49a

49b

E-Trucks Deployment Support 

and Incentives

2015-16

2018-20

Support for 1000 stage 2 trucks to reduce ROI to 5 years (assuming 

daily driving of 80% of energy storage capacity).

Support for Stage 3 Trucks to accelerate adoption

50 Electric Power TakeoffDeployment Support 

and Incentives

2015-17 Support for next-gen, stage 2 lower cost EPTO deployments

51 Plug-in Hybrids Deployment Support 

and Incentives

2015-17 Support for 500 stage 1 PHETs when they become commercially 

available.

52 AF Hybrid Deployment Support 

and Incentives

2015-17 Support for 200 NG hybrid refuse trucks.

53 AF Hybrid Pilot Demonstrations 2016-17 Pilot demos of NG/hybrid refuse trucks with downsized engines and/or 

80% less NOx.

54 Electric Corridor Pre-Commercial 

Demonstrations

2016-17 Demos of dual-mode hybrid and range-extended electric drayage 

trucks to broaden manufacturers offerings and truck types.

55 Optimized AF Engine Pre-Commercial 

Demonstrations

2016-17 Demos of 80% decreased NOx (NZEV).

56 Electric Corridor Deployment Support 

and Incentives

2016-17 Support for stage 2 PHET Class 7 & 8 drayage trucks (focus on Electric 

Corridor).

57 Alt Power Plants and 

Combustion Cycles

Deployment Support 

and Incentives

2016-18 Stage 2 tech support for 100 drayage truck buy-downs and introduce 

performance-based incentives for 200 low NOx higher efficiency linehaul trucks.

58 Engine Optimization Pilot Demonstrations 2017-18 Pilot demos of 55% brake thermal efficiency engines also incorporating 

all relevant technologies to achieve 2x truck efficiency improvement 

and 50% lower NOx

59 Hydraulic Hybrid Deployment Support 

and Incentives

2017-19 Support for first 300 vehicles in Class 2b when they become 

commercially available.

60 Optimized AF Engine Deployment Support 

and Incentives

2017-20 Introduce performance-based incentives for 200 NZEV/higherefficiency trucks.

61 Engine Optimization Deployment Support 

and Incentives

2017-20 Introduce performance-based incentives for early fleet deployments in 

California (1.5x efficiency conventional and 50% lower NOx) for first 

200 OTR trucks.

62 Hybrid Electric Pre-Commercial 

Demonstrations

2018-19 Demos of the more electric OTR hybrid truck.

63 Electric Corridor Deployment Support 

and Incentives

2018-20 Support for dual-mode hybrid and range-extended electric drayage.

64 AF Hybrid Deployment Support 

and Incentives

2018-20 Support for 100NG hybrid drayage trucks for ZEV Corridor.

65 Alt Power Plants and 

Combustion Cycles

Deployment Support 

and Incentives

2018-20 Support for fuel cell- and turbine-powered trucks and stage three 

technology trucks using performance based incentives

66 Engine Optimization Pre-Commercial 

Demonstrations

2019-

2020

Demo of 55% brake thermal efficiency engine incorporating all relevant 

technologies to achieve 2x truck efficiency improvement and 50% 

lower NOx.

Actions 45 through 66 in the CalHEAT Research and Market Transformation Roadmap for Medium- and 

Heavy-Duty Trucks are listed above by action number, technology strategy, action category, and years in 

which the action is planned, with a description.

California Hybrid, Efficient and Advanced Truck Research Center 
Draft Publication Rev # 7 Dated 6-14-2013

74

APPENDIX C:

Sixty-six Actions by Timeline and Action Category

The sixty-six actions in the Research and Market Transformation Roadmap for Medium- and HeavyDuty Trucks are summarized by action category and technology strategy in the five tables 

included in this Appendix, which cover Studies and Standards, Development, Pilot 

Demonstrations, Pre-Commercial Demonstrations, and Deployment Support and Incentives.

Table 7: Studies and Standards Action Summary

Studies and Standards

Includes business case studies, technology feasibility studies, complex modeling, and 

simulations. Also includes the creation of standards.

Technology 2013 2014 2015

HybridElectric

1. Industry assistance to understand 

California OBD Requirements

Electrified 

Accessories

2. Formulate and expedite adoption of 

standards such as voltage variants 

and J1939 signal controls

E-Trucks 3a Develop energy storage standards 

(pack level interfaces) to encourage 

greater selection and competition 

through SAE or IEEE, or regulation

3b Study best Applications for fast 

charging for increase truck and 

battery utilization

Plug-in 

Hybrids

4. Identify appropriate markets and 

truck platforms that have a potential 

business case 

22. Formulate a drayage 

truck economic model 

that captures externalities 

for ZEV corridor

Electric 

Corridor

5. Assess various roadway power 

systems and garner regional and 

statewide consensus on a standard 

for a pickup device

AF/Hybrid 6. Perform outreach to encourage an 

increase and broader selection of 

B20-certified engines

40. Understand potential for 

Cellulosic Ethanol, Methanol 

and DME as Hybrid and 

Optimized Engine Fuels

Studies and Standards planned in the CalHEAT Roadmap, shown by technology strategy and year.

California Hybrid, Efficient and Advanced Truck Research Center
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Table 8: Development Action Summary

Development

Development of a component, subsystem or complex drivetrain system

Technology 2013 2014 2015 2016

Hybrid-Electric 23. Develop prototypes for optimized and downsized engines to 

be used in hybrid systems

Electrified 

Accessories

7. Develop more purposely-designed electronics 

(but ideally shared architecture, DC-DC 

converters, auxiliary drives, power steering, 

pumps) that can be integrated into vehicles. 

8. Develop power distribution box/suppliers to 

allow for commonality across OEMs. (This is an 

enabler to further cost reduction.)

AF Hybrid 9. Develop smaller & lighter CNG tanks designed 

for HE trucks

Hydraulic Hybrid 10. Develop a light-weight advanced accumulators 41. Free Piston Engine 

Developments

Optimized AF 

Engine

11. Develop additional 

smaller engine sizes for 

efficiency and 

performance 

improvements 

(especially low-end 

torque)

24. Develop advanced engine efficiency strategies

and improved methane catalysts

12. Develop lower cost 

HHD NG solutions ( 

Heavy – Heavy 15 liter 

engines)

Waste Heat 

Recovery

13. Develop/apply thermoelectric designs to M-HD 

applications

Engine 

Optimization

14. Develop engines and systems to provide 50% 

reduced NOx

Alternative Power 

Plants and 

Combustion Cycles

15. FTA providing 

development funding 

for fuel cell transit 

buses, to reduce fuel 

cell cost, reducing 

footprint, increasing 

reliability

16. Develop new advanced engine 

designs such as camless, Opposed 

Piston, free piston and HCCI Engines

17. Develop purposely-devised 

turbinesfor vehicles

Development projects outlined in the CalHEAT Roadmap, shown by technology strategy and year.

California Hybrid, Efficient and Advanced Truck Research Center
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Table 9: Pilot Demonstration Action Summary

Pilot Demonstrations

A pilot demonstration is the full integration of a component, subsystem or complex drivetrain 

into1 to 5 trucks to evaluate performance.

Technology 2013 2014 2015 2016 2017 2018

Hybrid 

Electric

42. Pilot demos of optimized 

and downsized engine/s to be 

used in hybrid systems

Electrified 

Auxiliaries

43. Pilot demos for validation of 

electrified auxiliaries in Class 

7-8 (non-hybrid) tractors, line 

haul trucks and other trucks

E-Trucks 18. Pilot demos of smart 

charging systems

AF Hybrid 25. Pilot demos to 

evaluate/benchmark various 

NG/hybrid refuse trucks

53. Pilot demos of NG/hybrid 

refuse trucks with downsized 

engines and/or 80% less NOx

Hydraulic 

Hybrid

19. Pilot demos of stage 2 in 

Parcel ,Beverage Delivery, 

Buses and Yard Hostlers

Optimized 

Alternative 

Fuel Engines

20. Pilot demos of special CNG 

tanks with newer lighter 

materials

Waste Heat 

Recovery

26. Pilot demos of waste heat 

recovery in a vocational and 

line-haul trucks

Engine 

Optimization

44. Pilot demos of 50% break 

thermal efficiency engines

leveraging DOE program and 

also incorporating all relevant 

technologies to achieve up to 

1.5x truck efficiency 

improvement

58. Pilot demos of 55% break 

thermal efficiency engines also 

incorporating all relevant 

technologies to achieve 2x 

truck efficiency improvement

and 50% lower NOx

Alt Power 

Plants and 

Combustion 

Cycles

27. Pilot demos of Camless, 

Opposed Piston , free piston or 

HCCI engines in trucks

Pilot demonstrations planned in the CalHEAT Roadmap, shown by technology strategy and year.

California Hybrid, Efficient and Advanced Truck Research Center
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Table 10: Pre-Commercial Demonstration Action Summary

Pre-Commercial Demonstrations

Pre-commercial demonstrations involve 1 to 50 trucks to evaluate performance in the field. 

Further refinement precedes commercial production.

Technology 2013 2014 2015 2016 2017 2018 2019 2020

Hybrid Electric 21. Demos of next Stage 2 

hybrid drivelines with improved 

design and integration, and 

ARB OBD compliance and 

electrified accessories

62. Demos of the more 

electric OTR hybrid truck 

E-Trucks 28. Demos of improved 

integration- lower cost Stage 2 ETrucks, for ZEV Corridor

applications & goods movement

45. Demos of lower cost Stage 

3 E-Trucks, including longer 

ranges & fast charging

Electric Power 

Take-off

29. Demos of next-gen 

lower-cost Stage 2 

systems

Plug-in Hybrid 

Electric

30. Demos of goods 

movement and drayage 

trucks

31. DOE SCAQMD 

utility trucks (ARRA 

Funded)

32. Demos of Stage 1 

in Class 2b trucks

Electric 

Corridor

33. Demo of preferred on-road 

connection device for electric or 

PHET yard hostlers

54. Demos of dual-mode 

hybrid and range-extended 

electric drayage trucks to 

broaden mfrs offerings and 

truck types

AF Hybrid 34. Demos of new platforms of 

NG/hybrid drayage truck meeting 

ZEV Corridor requirements

Hydraulic 

Hybrid

35. Demos of 

Series, 

Enhanced 

Parallel 

and/or Dual 

Mode (Power 

Split) Stage 2 

Hybrids in 

refuse trucks

46. Demos of ultra-high 

efficiency Stage 3 technology 

using digital hydraulic 

components into a Class 2b 

and other larger truck 

platforms

Optimized AF 

Engine

36.Demos of lower engine sizes 

and new lower cost 15 liter 

engines to broaden number of 

platforms

55. Demos of 80% 

decreased NOx (NZEV)

Waste Heat 

Recovery

47. Demos of waste heat recovery in 

vocational and line-haul trucks

Engine 

Optimization

66. Demo of 55% brake 

thermal efficiency engine

with technologies to 

achieve 2x truck 

efficiency improvement

and 50% lower NOx

Alt Power

Plant/ 

Combustion 

Cycles

48. Demos of camless, Opposed 

Piston, free pistons and HCCI engines 

in trucks

Pre-commercial demonstrations in the CalHEAT Roadmap, shown by technology strategy and year.

California Hybrid, Efficient and Advanced Truck Research Center
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78

Table 11: Deployment Support and Incentives Action Summary

Deployment Support and Incentives

Policy and Regulatory Support and Financial Incentives for early deployment of commercial 

products in the marketplace

Technology 2013 2014 2015 2016 2017 2018 2019 2020

Hybrid 

Electric

37. Support for 1,000 

Stage 2 hybrids starting 

when they become 

commercially available

E-Trucks 49 A.Support for 1000 

Stage 2 trucks to reduce 

ROI to 5 years (assuming 

daily driving of 80% of 

energy storage capacity

49 B Support for Stage 3 Trucks to 

accelerate adoption

Electric 

Power Takeoff

50. Support for next-gen Stage 2 lower 

cost EPTO deployments

Plug-in 

Hybrid

51. Support for the first 500 Stage one 

PHETs when they become commercially 

available

Electric 

Corridor

56. Support for Stage 2 

PHET Class 7 & 8 

drayage trucks (focus on 

Electric Corridor)

63. Support for dual-mode hybrid and 

range-extended electric drayage

AF Hybrid 52. Support for 200 NG hybrid refuse 

trucks

64. Support for 100 NG hybrid drayage 

trucks for ZEV Corridor

Hydraulic 

Hybrid

38. Support for the first 100 Stage 2 

vehicles when they become 

commercially available

59. Support for first 300 vehicles in 

Class 2b when they become 

commercially available

Optimized 

AF Engine

39. Support for 1000 Stage 2 trucks 60. Introduce performance-based incentives for 200 

NZEV/higher-efficiency trucks

Engine 

Optimization

61. Introduce performance-based incentives for early 

fleet deployments in California (1.5X efficiency 

conventional and 50% lower NOx) for first 200 OTR 

trucks

Alternative 

Engines and 

Combustion 

Cycles

57. Stage 2 tech support for 100 

drayage truck buy-downs and introduce 

performance-based incentives for 200 

low NOx higher efficiency line-haul 

trucks

65. Support for fuel cell- and turbinepowered trucks and stage three technology 

trucks using performance based incentives

Deployment incentives and support planned in the CalHEAT Roadmap, shown by technology strategy 

and year.

California Hybrid, Efficient and Advanced Truck Research Center
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79

APPENDIX D:

Glossary

AB Assembly Bill 

AQMD Air Quality Management District

ARB Air Resources Board

BTE Brake Thermal Efficiency

CalEPA California Environmental Protection Agency

CEC California Energy Commission

CO2e Carbon dioxide equivalents

DOE U.S. Department of Energy

DOT U.S. Department of Transportation

EMFAC EMissions FACtor, a computer model for quantification of pollutants 

from on-road sources

EPA Environmental Protection Agency

EPTO Electrified Power Take-off

HDV Heavy-duty vehicle

HEV Hybrid EA Electric Vehicle

g/bhp-h Grams/brake horse power per hour

GHG Greenhouse gas

LNA Low NOx Ammonia application

LNC Lean NOx Catalysts

MDV Medium-duty vehicle

MMT Million Metric Tons

MMTCO2e Million Metric Tons of CO2Equivalent Emissions

NACFE North American Council for Freight Efficiency

NHTSA National Highway Traffic Safety Administration

NOx Oxides of Nitrogen
Draft Publication Rev # 7 Dated 6-14-2013

80

OBD On-board Diagnostics 

OEM Original Equipment Manufacturer

PHET Plug-in Hybrid Electric Truck

PIER Public Interest Energy Research

PM Particulate matter

PTO Power Take-off

ROI Return on Investment

RPM Revolutions per Minute

SCR Selective Catalytic Reduction

Supertruck Under its Supertruck program, the DOE has funded demonstration 

projects of Class 8 long-haul trucks that incorporate a wide range of 

technologies developed under the 21st Century Truck Partnership, with 

the objective of creating highly efficient and clean-burning dieselpowered trucks with 50% or greater vehicle freight efficiency and brake 

thermal efficiency.

xEV Fully Electric Vehicle

ZEV Corridor Zero-emission Corridor