NREL is a national laboratory of the U.S. Department of Energy, Office of Energy

Efficienc y & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

Contract No. DE

- AC36

- 08 GO28308 

# Eighteen

- Month Final Evaluation

of UPS Second Generation Diesel Hybrid

- Electric Delivery Vans

M. Lammert and K. Walkowicz National Renewable Energy Laboratory

Technical Report

NREL/TP

- 5400

- 55658 September 2012NREL is a national laboratory of the U.S. Department of Energy, Office of Energy
Efficiency & Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.

National Renewable Energy Laboratory 15013 Denver West Parkway Golden, Colorado 80401

303

- 275

- 3000 • www.nrel.gov

Contract No. DE

- AC36

- 08GO28308 

# Eighteen

- Month Final Evaluation

of UPS Second Generation Diesel Hybrid

- Electric Delivery Vans

M. Lammert and K. Walkowicz National Renewable Energy Laboratory

Prepared under Task No. FC08.3000

Technical Report

NREL/TP

- 5400

- 55658 September 2012NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents t hat its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

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.iii 

### Acknowledgments

This evaluation is funded through the Advanced Vehicle Testing Activity, which is managed by Lee Slezak within the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy . All publications regarding the United Parcel Service ( UPS ) hybrid delivery

van evaluation will be posted on DOE’s Energy Efficiency and Renewable Energy Web site. See

the Medium

- and Heavy

- Duty Vehicles se ction at the following link: http://www1.eere.energy.gov/vehiclesandfuels/avta/index.html

.

This evaluation , conducted at UPS

, would not have been possible without the support an d cooperation of many people. The author s wish to thank each of the following:

U.S. Department of Energy

Lee Slezak

UPS

Mike Britt

James C. Francis Andy Grzelak

Robert K. Hall

Bill Brentar

Eaton Corporation Alex Stuckyiv 

## List of Acronyms and Abbreviations

AVTA Advanced Vehicle Testing Activity

CANBUS controller area network bus

CARB California Air Resources Board

cfm cubic feet per minute

CFR Code of Federal Regulations

CO carbon monoxide

CO 2 carbon dioxide

CR Conventional Route

DOE U.S. Department of Energy

DPF diesel particulate filter

FT&E Fleet Test and Evaluation (NREL team)

GPS global positioning system

HC hydrocarbon

HHDDT Heavy Heavy

- Duty Diesel Truck (duty cycle) hp horsepower

HTUF4 Hybrid Truck Utility Forum Class 4 (duty cycle)

KI kinetic intensity

kW kilowatt

mpg miles per gallon mph miles per hour

MY model year

NO

x oxides of nitrogen

NREL National Renewable Energy Laboratory NYC Comp New York City Composite (duty cycle)

PM particulate matter

ReFUEL Renewable Fuels and Lubricants (Laboratory)

THC total hydrocarbons

UPS United Parcel Service

VDC voltage direct currentv 

### Executive Summary

This 18

- month final evaluation is part of a series of evaluations by the U.S. Department of Energy (DOE). Using an established and documented evaluation protocol, DOE

— through the National Renewable Energy Laboratory (NREL)

— has been tracking and evaluating new propulsion systems in transit buses and trucks for more than 10 y ears. The DOE/NREL vehicle evaluations are a part of the Advanced Vehicle Testing Activity (AVTA), which supports DOE’s Vehicle Technologies Program.

The role of AVTA is to bridge the gap between research and development and the commercial availability of advanced vehicle technologies that reduce petroleum use in the United States and improve air quality. The main objective of AVTA projects is to provide comprehensive, unbiased evaluations of advanced vehicle technologies in

commercial use. Data are collect ed and analyzed for operation, maintenance, performance, costs, and emissions characteristics of both advanced

- technology fleets and comparable conventional

- technology fleets that are operating at the same site. AVTA

evaluations enabl e fleet owners and ope rators to make informed vehicle

- purchasing

decisions.

This report focuses on a parallel hybrid

- electric diesel delivery van propulsion system currently being operated by United Parcel Service ( UPS ) . The propulsion system is an

alternative to the standard d iesel system and could enable reductions in emissions as well

as reductions in petroleum use.

Evaluation Design

This 1 8

- month evaluation used eleven P 10 0H hybrid van s and eleven P 10 0D

conventional van s that are located at a UPS facilit y i n the Minneapolis, Minnesota

, area. On

- vehicle data logging, fueling, and maintenance records are used to evaluate the performance of these hybrid step delivery vans in

- use

. The two study groups switched route assignments during the study to provide a more balan ced review of the vehicles on the same routes.

In addition, a P 10 0H hybrid and a P100D conventional were tested at NREL’s Renewable Fuels and Lubricants ( ReFUEL ) research laboratory

. Testing was performed

over thre e standard drive cycles to evaluate the fu el economy and emissions benefits gained through hybridization

.

Evaluation Results The results and related discussions included here focus only on the selected facilities, the

two P 10 0 study groups

, and the two P100 vehicles tested at the ReF UEL lab oratory

.

Van Use and Duty Cycle Route and drive cycle analysis showed that the study groups were on different duty cycles and would require a route switch between the study groups to provide a valid comparison

, which UPS accommodated. The hybrid group accu mulated 33 % fewer miles

than the conventional group during the complete 18

- month study. The hybrid group accumulated miles at a slower rate than the conventional group during the 13 months ofvi the original route assignments

, indicating more “urban” route as signment s with a short highway leg to the delivery area , but then accumulated mile s at a faster rate than the conventional group for the 5 months after the route switch when they were assigned the original conventional routes

.

In

- Use Fuel Economy

F uel economy was evaluated during equal 5

- month periods from different years . During the second period, the route assignment s originally assigned to the conventional and hybrid van groups were swapped so that the conventional vehicles were assigned to the origi nal hybrid van routes and vice versa

.

• Analysis of i nitial c onventional route assignment s ( lower kinetic intensity ) : Fuel economy of the hybrid group on the original c onventional route assignments over 5 months was 10.4 mpg

, 13% greater than the 9.2 mpg of the conventional group on those routes a year earlier

.

• Analysis of initial hybrid route assignments (higher kinetic intensity): Fuel economy of the hybrid group on the original hybrid route assignment s over 5

months was 9.4 mpg

, 20% greater than the 7.9 mpg of the conventional group on those routes a year later

. The difference in hybrid advantage in fuel economy is as expected

. The hybrids demonstrated a greater advantage on the initial hybrid route assignments

, which wer e

more “ urban ” ( low speed, high stops

- per

- mile routes ) and lower advantage on initial

conventional route assignments with a longer highway leg and less dense delivery zones

.

Maintenance Costs There was no statistically significant difference in t otal maintenance cost per mile (P value = 0.1128)

.

Propulsion

- related maintenance cost per mile was 77% higher for the hybrids (P value = 0.0278). However, this was only 52% more when considered on a cost per delivery day

basis.

Fuel Costs Hybrid fuel cos ts per mile were 1 1 % less than for the conventional van s when a fuel price

of $3.58/gallon ( the average cost of diesel during the study ) is used

.

Operating Costs Hybrid vehicle total cost of operation per mile (assuming $3.58/gal) was 3 % more than

the cost of operation for the diesel group ($0. 59 vs. $0. 57 per mile), but not found to be statistically significant (P value = 0.9677).

Reliability The hybrid group had a cumulative uptime of 92.5% compared to the conventional group uptime of 99.7%.vii Laboratory Testing Laboratory dynamometer testing demonstrated 13 %

– 36 % hybrid fuel economy improvement, depending on duty cycle

, and up to a 45 % improvement in ton

- mi/gal.

Laboratory testing demonstrated an increase in emissions of oxides of nitrogen of 21% to

49% fo r the hybrid.viii 

### Table of Contents

Executive Summary

................................ ................................ ................................ ....................... v

Evaluation Design

................................ ................................ ................................ ............. v Evaluation Results

................................ ................................ ................................ ............. v

Overview

................................ ................................ ................................ ................................ ......... 1

Advanced Vehicle Testing Activity

................................ ................................ .................. 1 Project Design and Data Collection

................................ ................................ .................. 2

Host Site Profile

— UPS, Minneapolis, Minnesota

................................ ............................ 6

Evaluation Results

................................ ................................ ................................ ......................... 6

Van Use

................................ ................................ ................................ ............................. 6 Van Duty Cycle

................................ ................................ ................................ ................. 8 Fuel Economy

................................ ................................ ................................ .................. 12

Similar R oute Fuel Economy Analysis

................................ ................................ ........... 13

18

- Month Fuel Economy

................................ ................................ ................................ . 14

Maintenance Cost Analysis

................................ ................................ ............................. 15

Maintenance Costs

................................ ................................ ................................ ........... 16 Total Cost per Mile

................................ ................................ ................................ .......... 21 Reliability

................................ ................................ ................................ ........................ 21

Batteries

................................ ................................ ................................ ........................... 22

Laboratory Fuel Economy and Emissions Testing

................................ ................................ .. 22

Test Cycle Selection

................................ ................................ ................................ ........ 22

Test Plan

................................ ................................ ................................ .......................... 26 Vehicle Specifications

................................ ................................ ................................ ..... 26 Laboratory Test Results

................................ ................................ ................................ ... 27 Comparison of Laboratory Results to In

- Use Results

................................ ..................... 29 Status of UPS Hybrid Fleet

................................ ................................ ............................. 30

Conclusions

................................ ................................ ................................ ................................ .. 31

Contacts

................................ ................................ ................................ ................................ ........ 32

Appendix: Laboratory Description and Test Methods

................................ ............................. 33

General Lab Description

................................ ................................ ................................ .. 33 Chassis Dynamometer

................................ ................................ ................................ ..... 33 Fuel Storage and Blending

................................ ................................ .............................. 34 Fuel Metering and Conditioning

................................ ................................ ..................... 35 Air Handling and Conditioning

................................ ................................ ....................... 35

Emissions Measurement

................................ ................................ ................................ .. 35ix 

### List of Figures

Figure 1. UPS hybrid van.

................................ ................................ ................................ .. 2 Figure 2. Eaton hybrid system schematic

................................ ................................ ........... 3 Figure 3. Eaton hybrid system components

................................ ................................ ........ 4 Figure 4. Eaton hybrid system components on UPS undercarriage

................................ .... 5 Figure 5. Hybrid and conventional monthly mileage per van

................................ ............ 7 Figure 6. Hybrid and conventional cumulative mileage per group

................................ .... 7 Figure 7. Hybrid and conventional route visualization

................................ ....................... 9 Figure 8. Hybrid and conventional duty cycle breakdown by miles %

............................ 10 Figure 9. Hybrid and conventional du ty cycle breakdown by miles traveled

.................. 11 Figure 10. Route switch fuel economy analysis time periods

................................ .......... 13 Figure 11. Total maintenance cost per mile

................................ ................................ ...... 18 Figure 12. Propulsion maintenance cost per mile

................................ ............................. 19 Figure 13. Propulsion maintenance cost per mile (conventional va ns)

............................ 20 Figure 14. Propulsion maintenance cost per mile (hybrids)

................................ ............. 20 Figure 15. Cumulative uptime

................................ ................................ .......................... 22 Figure 16. Average driving speed and KI comparison

................................ ..................... 23 Figure 17. Stops per mile and KI comparison

................................ ................................ .. 24 Figure 18. NYC Comp trace

................................ ................................ ............................. 24 Figure 19. HTUF Class 4 trace

................................ ................................ ......................... 25 Figure 20. CARB HHDDT trace

................................ ................................ ...................... 25 Figure 21. Laboratory fuel economy

................................ ................................ ................ 27 Figure 22. Laboratory ton

- mi./gallon fuel economy

................................ ......................... 28 Figure 23. Laboratory NO

x emissions

................................ ................................ .............. 29 Figure 24. Laboratory and in

- use fuel economy results

................................ ................... 30



### Li st of Tables

Table 1. FT&E Heavy

- Duty Vehicle Evaluations

................................ .............................. 1 Table 2. Hybrid Propulsion

- Related Systems

................................ ................................ ..... 3 Table 3. Vehicle System Descriptions

................................ ................................ ................ 5 Table 4. Drive Cycle Statistics from Vans with GPS Loggers from Each Study G roup (before any routing changes)

................................ ................................ ................... 12 Table 5. Route Switch Fuel Economy (in

- use records) of Hybrid and Conventional Vans

on Two R oute Sets

................................ ................................ ................................ ... 14 Table 6. Hybrid and Conventional Van Fuel Use and Economy

................................ ...... 14 Table 7. Hybrid and Conventional Group Total and Propulsion Maintenance Costs

...... 16 Table 8. Hybrid and Conventional Van Total Cost per Mile

................................ ............ 17 Table 9. Hybrid and Conventional Van Propulsion Cost per Mile

................................ ... 17 Table 10. Hybrid and Conventional Van Total Cost per Mile

................................ .......... 21 Table 11. Test Cycle Statistics and In

- Field Average Comparison

................................ .. 26

Table 12. Test Vehicle Information

................................ ................................ .................. 26 Table 13. Fuel Economy of Hybrid and Conventional Van on Various Cycles on Chassis Dynamometer

................................ ................................ ................................ ........... 27x Table 14. Ton Fuel Economy of Hybrid and Conventional Van on Various Cycles on

Cha ssis Dynamometer

................................ ................................ ............................. 28 Table 15. Average NO

x Emission Results of Hybrid and Conventional Vans on Specified Cycles

................................ ................................ ................................ ....................... 28 Table 16. Average Values for Emission Results of Hybrid and Conventional Vans on Specified Cycles

................................ ................................ ................................ ....... 291 

### Overview

Advanced Vehicle Testing Activity The role of the U.S. Department of Energy’ s (DOE’s) Advanced Vehicle Testing Activity (AVTA) is to help bridge the gap between research and development and commercial availability for advanced vehicle technologies that reduce petroleum use and meet air-quality standards. AVTA supports the DOE’s Vehicle Technologies Program by examining marketfactors and customer requirements and evaluating the performance and durability of alternativefuel and advanced-technology vehicles in flee t applications. The Na tional Renewable Energy Laboratory’s (NREL’s) Fleet Te st and Evaluation (FT&E) te am conducts evaluations with support from AVTA.

The main objective of FT&E projects is to conduct comprehensive, unbiased evaluations of advanced-technology vehicles. Data collected and analyzed include the operations, maintenance, performance, cost, and emissions characteri stics of advanced-technology vehicles and comparable conventional technology in fleets operating at the sa me site. The FT&E evaluations help fleet owners and operators make informed vehicle-purchasing deci sions. The evaluations also provide valuable data to DOE about th e maturity of the te chnology being assessed.

The FT&E team has been conducting several ev aluations of advanced-propulsion heavy-duty vehicles (see Table 1). Information on thes e and other evaluations involving advanced technologies or alternative fuels, such as biodiesel and Fischer- Tropsch diesel, is available at www.nrel.gov/vehiclesandfuels/fleettest.

Table 1. FT&E Heavy-Duty Vehicle Evaluations

Fleet Location Vehicle Technology Evaluation Status

Coca Cola

Refreshments Miami, FL 2010 Kenworth

T-370 Tractors Eaton Hybrid Electric Propulsion Completed in August 2012

UPS Phoenix, AZ 2007 Freightliner P70 Eaton Hybrid Electric Propulsion Completed in

FedEx Los Angeles,
CA Ford E-450 strip

chassis Gasoline hybrid electric parcel delivery trucks, Azure Dynamics Completed in January 2011

UPS Phoenix, AZ P70 Delivery Van Parallel hybrid, Eaton system Completed in

December 2009 Long Beach

Transit Long Beach,
CA New Flyer 40-ft low

floor transit bus Gasoline-electric series hybrid Completed in June

2008

Metro St. Louis, MO Gillig 40-ft transit bus Biodiesel blend (B20) Completed in July

2008

New York City Transit Manhattan, NY; Bronx, NY Orion VII 40-ft transit

bus Series hybrid, BAE Systems HybriDrive propulsion system (diesel), order of 200 (Gen II); order of 125 (Gen I) Completed in January 2008

New York City Transit Manhattan, NY; Bronx, NY Orion VII 40-ft transit

bus Series hybrid, BAE Systems HybriDrive propulsion system (diesel), order of 125; DDC S50G compressed natural gas engines Completed in

November 2006

Denver RTD Boulder, CO Gillig 40-ft transit bus Biodiesel blend (B20) Completed in
October 2006 King County

Metro Seattle, WA New Flyer 60-ft

articulated transit bus Parallel hybrid, GM–Allison EP 50 System (diesel) Completed in

December 2006

IndyGo Indianapolis, IN Ebus 22-ft bus Series hybrid, Capstone MicroTurbine (diesel) Completed in 2005

Knoxville

Area Transit Knoxville, TN Ebus 22-ft bus Series hybrid, Capstone MicroTurbine (propane) Completed in 2005 March 20122 Project Design and Data Collection This report discusses a n 1 8

- month i n

- use evaluation of 11 model year (MY) 20 10 Freightliner

P 10 0H hybrid step delivery van s (Figure 1) that were placed in service at Un i t ed Parcel Service’s (UPS’s) facility in Minneapolis, Minn esota , during the first half of 20 10

. These new hybrids are

an evolution from UPS’s original 50 Eaton hybrids that NREL documented in 12

- month and 36

- month studies

. 1 The new hybrids have more advanced control algorithms and an integrated

“ engine off at idle ” feature that automatically stops and restarts the engine at stoplights and other short stops when certain conditions are met. These hybrid vehicles are evaluated against 11 MY

20 10 Freightliner P 10 0D conventional step delivery van s that were placed in service at the same facility a couple months after the hybrids . The conventiona l vans were chosen using UPS’s database and comparing the average miles per day of the 11 hybrids to that of conventional vans that had the same size and cargo capability

. Even so, the route profiles a re very different

, requiring a route assignment switch between the groups to be evaluated in this report

. All fueling

and maintenance data were collected by UPS f r o m its databases and were shared with NREL for

this evaluation.

Figure 1. UPS hybrid van

. 2

1 See http://www.nrel.gov/vehiclesandfu els/fleettest/research_hybrid_ups.html

. 2 This image is reproduced with permission of United Parcel Service of America, Inc. © 2011 United Parcel Service of America, Inc. All rights reserved. Photo from UPS, NREL/PIX 19821

.3 Table 2 presents additional details on Eaton Corporation’s parallel hybrid system

, and Figure 2 provides a schematic of the system

.

Table 2. Hybrid Propulsion

- Related Systems

Category Hybrid Van Description

Manufacturer/integrator Eaton Corporation

Transmission Fulle r medium

- duty automated manual

6

- speed Prototype

Motor Synchronous brushless, permanent magnet Continuous power

, 26 kW

P eak power

, 44 kW

Energy storage Lithium ion batteries

340 VDC

1.8 k Wh total storage

Figure 2 . Eaton hybrid system schematic4 Figure 3 shows the primary hybrid components in the Eaton system.

Figure 3 . Eaton hybrid system components5 Figure 4 shows the primary hybrid components arranged in the undercarriage of a UPS delivery

van.

Figure 4 . Eaton hybrid system components on UPS undercarriage

UPS has custom delivery vans built to the company’s specifications

. The P100 vehicles in this study are manufactured by Freightliner for UPS. Table 3 provides brief descriptions of the vehicle systems.

Table 3. Vehicle System Descriptions

Van Specification Hybrid Electric Vans Conventional Vans

Van manufacturer Freightliner Corp. Freightliner Corp.

Van model P 10 0H step van P 10 0D step van

Van m odel year 20 10 20 10

Engine manufacturer and model Cummins ISB 200 HP

MY 200 9 Cummins ISB 200 HP

MY 2009
Emissions equipment DPF DPF

Retarder/regenerative braking Regenerative braking None

Air conditioning type None None

Gross vehicle weight rating 23,000 lbs 23,000 lbs

DPF = diesel particle filter Diesel Engine

Electric Motor

Transmission 

## Front of Vehicle

High Voltage AC Cables (bright orange)

Power Electronics

Carrier6 Host Site Profile

— UPS, Minneapolis, Minnesota

The host site consist s of one large distribution facility in Minneapolis

. E leven hybrid van s and 11

conventional van s were used for this evaluation. It was not necessary to modify the Minneapolis facility in any way to implement the hybrid vehicles into the fleet

. Drivers were given training on the operation of the hybrids, but no restrictions o r special accommodations were made for their

use ; however , UPS did assign the hybrid vans to urban routes rather than rural routes to make the

best use of the hybrid drive train

. Dispatch and maintenance practices are the same for both vehicle study groups . The Minneapolis facility has on

- site fueling

, and the vehicles are fueled by drivers as needed, using an internal fuel card system. T he drivers then log their fueling events on their electronic tablets, and the records are uploaded to a central database

. Failure on the part of the driver to log fueling events led to some months from each study group being left out of fuel economy calculations due to inaccurate fueling data

.



### Evaluation Results

Van Use Figure 5 shows the average monthly miles driven per v an for each van group with ± 95%

confidence interval lines

. The width of the 95% confidence interval gives some idea about how uncertain we are about the average based on the variation observed in the data

. Hybrid v ans were placed in service at the end of M arch 2010

. Conventional vans were placed in service from March through June 2010

. As such, July 2010 is the “clean point” in the data when all study

vehicles are assumed to be operating in a normal fashion

. Monthly usage did not change significantly after the clean point until June 2011 ; t he hybrids consistently were driven roughly half as many miles throughout this period because of the shorter, denser urban routes they were purposely assigned to. In June 2011 , a route switch was initiated to balance the e valuation and provide data for both vehicle groups on both route types. Vehicles from each group were assigned routes previously assigned to the other group ; the drivers kept their original route assignments but with a new vehicle. The area in orange denot es when the route switch took place between the groups

, causing the mileage change from June into August 2011 . Note that not only did the average miles per van swap , but also the width of the 95% confidence interval lines

swapp ed as well. The original dies el group routes had a wide range of daily miles driven while the hybrids were on routes with more tightly grouped daily miles.7 Figure 5 . Hybrid and conventional monthly mileage per van

Figure 6 shows the cumulative monthly miles driven by each van study group

. The area in orange denotes when the route switch took place between the groups

. Evidenced here again is the

much slower mileage accumulation of the hybrids until the route switch time frame. At that point

, the hybrid group began accruing miles faste r than the conventional van group

.

Figure 6 . Hybrid and conventional cumulative mileage per group8 Van Duty Cycle Isaac Instruments DRU900/908 data logging devices (Isaacs) with global positioning system ( GPS ) antennas and J1939 controller area network bus ( CANBUS ) connection s were deployed to

the UPS fleet on two occasions. The first period covered was from July 14, 2010

, to July 29,

2010

, and the second was from April 12, 2011

, to June 21, 2011. During the first period, only

three Isaacs were available

, and on the second occasion seven vans from each group were

instrumented with the devices for most of the duration (including one that had been instrumented during the previous period )

. In total

, 338 days of hybrid operation and 252 days of conventional

o peration on eight vans from each group were documented. The GPS and J1939 channels were recording at a 5

- H z rate. Twenty

- three J1939 CANBUS channels where recorded

, inclu ding

wheel

- based vehicle speed, engine speed, and engine fuel rate. The data presented here are not representative of the entire UPS fleet or even of the entire depot, but only of the P 10 0 study vehicles. Figure 7 shows a GPS visualization of some typical routes of thirteen logged vans . The exact routes vary daily, but the depictions shown are typical of a day of operation for that van as captured by the GPS loggers and show the operation of the hybrids being near the depot with less

“ stem ” time while the conventional vehicles include more “ stem ” time prior to arriving at the delivery area.

Comparing the routes driven by the two groups is difficult because of the disparity in the average daily miles driven . Initially, the conventional vans averaged 64 miles a day while the hybrids averaged on ly 43 miles a day

. Figure 8 shows the average distance (as a percentage) that vans with GPS loggers drove at different vehicle speeds. The hybrids drove a greater percentage of their distance at slower speeds than the conventional van s did, and the convent ional van s drove more of their miles operating at higher speeds.

• The hybrid vans drove 44% of their miles below 20 mph, while the conventional vans drove only 30.5% of their miles at those slow speeds.

• The van groups drove a similar percentage of their mi les at the intermediate speeds of

20

– 50 mph: 47% for conventional and 43% for hybrids.

• The hybrid vans drove only 13% of their miles above 50 mph, while the conventional

vans drove 22% of their miles at those highway speeds.

The greater percent of miles driven by the hybrids at slower speeds is an indication of a more urban duty cycle

. The lower percentage of miles driven at highway speeds is an indication of routes closer to the depot.9 Figure 7 . Hybrid and conventiona l route visualization10 Figure 8 . Hybrid and conventional duty cycle breakdown by miles %

Figure 9 shows the average distance (in miles) that vans with GPS loggers drove at different vehicle speeds. This distance based chart highlights a different breakdown of the routes

.

• The conventional vans drove more miles at all speeds above 10 mph.

• The hybrid and conventional vans both drove 17 miles in the 0

– 20 mph range.

• The hybrid vans drove 37 % fewer miles in the 20

– 50 mph range : 19 vs

. 30

. This

indicates the conventional vans had lo nger surface street drive s between delivery stops.

• The hybrid vans drove 62% fewer miles in the 50+ mph highway range : 6 vs

. 15

. This

indicates the conventional vans had longer highway legs to get to their assigned delivery

areas. 0 5 10 15 20% of Distance



### Vehicle Speed (mph) 

## UPS Minneapolis

Conventional vs hybrid delivery duty cycle

Conventional; Total distance traveled = 63.8 miles

Hybrid; Total distance traveled = 42.5 miles11 Figure 9 . Hybrid and conventional duty cycle breakdown by miles traveled

Table 4 presents other duty

- cycle statistics gathered from the GPS data logging.

• The hybrid van s’ average driving speed of 16.5 mph was 21 % lower than the

conventional vans ’ 20.7 mph.

• The hybrid van s averaged roughly the same number of stops per day as the conventional

vans ’ ( 205 for the hybrid vans vs

. 220 for the conventional van s).

• The hybrid van s had 5.3 stops per mile, 3 7% more than the conventional vans ’ 3.9

.

• The hybrid van s had 25.7 accelerati on events per mile, 34 % more than the conventional

vans ’ 19.2

. These statistics indicate that the hybrid van s were initially operating on very different route type s (urban vs. rural) than the conventional van s. Because of these m ajor differences

, the stud y groups switched route assignments in June /July 2011

. As of August 2011 the hybrid vans had assumed the drive characteristics of the conventional group and the conventional vans had assumed the drive characteristics of the hybrid group. The h ybrid fuel economy advantage

discussed below will be compared while the groups were on the same routes rather than during the same time periods

. Thus, we will gain an understanding of hybrid advantage on two very different route sets, one more dense ly urban and one with more of a highway leg and extended surface street driving between stops. 0 2 4 6 8 10Miles Traveled



### Vehicle Speed (mph) 

## UPS Minneapolis

Conventional vs hybrid delivery duty cycle

Conventional; Total distance traveled = 63.8 miles

Hybrid; Total distance traveled = 42.5 miles12 Table 4 . Drive Cycle Statistics from Vans with GPS Loggers from Each Study Group (before any routing changes)

Cycle Statistics Conventional Average Hybrid Average Difference ( Conventional

- Hybrid) % Difference

Distance traveled (miles) 63.8 42.5 21.3

- 33 % Average speed over cycle (mph) 11.8 8.3 3.5

- 30 % Average driving speed (mph) 20.7 16.5 4.3

- 21 %

Maximum speed (mph) 66.2 60.5 5.7

- 9 %

Time at zero speed (s) 8

, 670.0 9

, 059.6

--- --- Acceleration (% of total cycle) 29.5 26.6 2.9

- 10 % Deceleration (% of total cycle) 27.6 23.9 3.7

- 1 3 %

Average acceleration (ft/s 2 ) 2.2 1.9 0.3

- 14 %

Average deceleration (ft/s 2 )

- 2. 3

- 2. 1

- 0.2

- 8 %

Number of acceleration

events 1

, 157.5 1

, 015.9 141.7

- 12%

Number of acceleration events per mile 19.2 25.7

- 6.5 34%

Number of deceleration

events 1

, 157.5 1

, 015.9 141.7

- 12%

Number of deceleration events per mile 19.2 25.7

- 6.5 34%

Number of stops 219.9 205.1 14.8

- 7 %

Number of stops per mile 3.9 5.3

- 1.4 37%

Fuel Economy UPS fuels its hybrid and conventional van s with standard ultra

- low

- sul f ur diesel

. Because of the very different route assignments for the hybrid and conventional van groups

, a route switch was necessary to evaluate the in

- use performance fairly

. As such fuel economy is considered for the

entire 18

- month study period as well as comparing both groups on the same routes during different time periods

. One hybrid van clearly was missing many fueling events, including 5 months with no fueling events recorded

, while still reporting normal mileage accumulation. After

the route switch

, a conventional van now assigned to that route showed the same behavior. Most fuel economy months fro m that route were removed from this report , but the affected vans are

still fully considered in the maintenance analysis and reliability section s

. Chauvenet’s Criterion was used to identify van monthly MPG r esults that were statistical outliers

. This metho d

removed 22 vehicle

- months from the conventional van group and 48 vehicle

- months from the hybrid van group that were statistically not possible to occur for that particular vehicle based on

that vehicle ’ s performance during each of the two route assignmen t periods . A 95% confidence interval outlier analysis removed an additional 4 vehicle

- months from the conventional group that had a very low likelihood of occurring

. Most of the removed data points were obviously impossible for the vehicles to attain, but by using a consistent statistical approach the grey areas

for each vehicle were treated in the same manner

. In total, 74 vehicle

- months were removed from the original data set of 396 vehicle

- months.13 Similar Route Fuel Economy Analysis UPS implement ed a complete route switch of each of the 11 study vans in both groups from June 2011 through early August 2011

. F uel economy was analyzed f or each route over similar calendar year time periods ( August 1 through December 31 of both 2011 and 2012 )

. Limiting t he comparison to these months reduces the affect of seasonal variations both in weather and load

. This five

- month snapshot compares the conventional vans on their original route assignments [ Conventional Route (CR) 1 p eriod ] to the hybrid vans on those rou tes a year later and the hybrid vans on their original route assignments to the conventional vans on those routes a year later ( Conventional Route 2 p eriod)

. Drivers stayed with their known routes and were assigned a new

vehicle

. Drivers receiving the hybr ids had to receive training on their operation before the switches could be implemented. Figure 10 illustrated the route assignment time periods being compared.

Figure 1 0 . Route sw itch fuel economy analysis time periods

**Route E**  **ffect on Fuel Economy** 

Both s tudy groups had low er mpg on Conventional Route 2 than on Conventional Route 1 : 14%

lower for the conventional vans and 9% lower for the hybrid van s, which validates the statistical duty cycle analysis indicating that the conventional group was on a less demanding duty cycle while the hybrids were on a more demanding one

. Both groups accumulated about half as many

miles on Conventional Route 2 as on Conventional Route 1, showing that the route switch was implemented effectively and the groups assumed each other’s drive characteristics after the

swap

. Table 5 shows the group fuel economy comparison for the route switch. Also of note is

that the h ybrid a dvantage was 13% on the less kinetically intense

, more highway

- biased route assignments (Conventional Route 1)

, matching well with the laboratory results on the Heavy Heavy

- Duty Diesel Truck ( HHDDT ) cycle presented later in this report

, while they achieved a 20% hybrid advantage on the more kinetically intense Conventional Route 2 assignments14 (although th e second route comparison was not quite statistically significant because remov ing fueling months eliminat ed some vans , which reduced the sample set).

Table 5. Route Switch Fuel Economy (in

- use records) of Hybrid and Conventional Van s on Two

Route Sets

Conventional Route

1 Conventional Route

2 Effect of Higher KI

R oute A ssignment

Conventional Aug thru Dec 2010 Aug thru Dec 2011
Mileage 75,404 37,901

- 50%

Fuel 8,233 4,822

- 41%
Group MPG 9.2 7.9

- 14%

MPG Vehicle Months 51 44
Hybrid Group Aug thru Dec 2011 Aug thru Dec 2010
Mileage 62,991 32,149

- 49%

Fuel 6,086 3,417

- 44%
Group MPG 10.4 9.4

- 9%

MPG Vehicle Months 46 39
Hybrid Advantage 13% 20%

t

- test P v alue (cumulative mpg of

individual vans in the group) 0.0015 0.1468

KI = kinetic intensity

18

- Month Fuel Eco nomy Because the original route assignments were so different as to necessitate a route switch to fairly compare the fuel economy performance of the groups

, the overall average fuel economy of the groups over the total 18 month s is of little analytical value

. However, those statistics are included here for completeness even though no conclusions of relative performance can be drawn

. Table 6 shows the fuel consumption and economy data for each van in each study group. The hybrid vans consumed 14,615 gallons of fuel over 145,568 miles for the 18

- month period, resulting in an average fuel economy for the hybrid vans of 10.0 mpg

. T he conventiona l van group consumed 24,673 gallons of fuel over 218,225 miles for an average of 8.8 mpg.

Table 6 . Hybrid and Conventional Van Fuel Use and Economy

Hybrid Vehicles

Van Fuel Economy

Miles Fuel Economy
Gallons Miles per
Gallon

144561 14,119 1,557 9.1

144564 17,067 1,570 10.9

144590 21,816 1,996 10.9

144594 5524 547 10.1

144595 11,986 1,166 10.3

144596 13,028 1,367 9.5

144597 11,193 1,292 8.7

144598 12,383 1,271 9.7

144712 14,843 1,547 9.6

144719 18,313 1,923 9.515 Hybrid Vehicles

Van Fuel Economy

Miles Fuel Economy

Gallons Miles per

Gallon

144736 10,820 926 11.7

Hybrid Total 145,568 14,615 10.0

Conventional Vehicles

Van Fuel Economy

Miles Fuel Economy

Gallons Miles per

Gallon

149765 19,684 2,235 8.8

149772 16,685 1,983 8.4

149777 16,994 2,167 7.8

149779 20,154 2,180 9.2

149780 17,159 1,843 9.3

149783 13,025 1,511 8.6

149784 12,580 1,461 8.6

149831 21,452 2,514 8.5

149832 22,811 2,536 9.0

149833 36,216 3,855 9.4

149871 21,465 2,388 9.0

Conventional

Total 218,225 24,673 8.8

Maintenance Cost Analysis This evaluation focuses on van operations spanning 18 of the first 21 months of operation for the hybrid and conventional vans . This snapshot does not yield enough operating cost data to provide a complete understanding of the full life

- cycle cost of the hybrid vans. Understanding costs requires an examinatio n of the purchase cost of the vans plus warranty and operation costs

as well as longer

- term maintenance activities

, such as engine rebuilds or replacements and battery replacements

, which also must be considered. Finally, it is critical that areas in which cost savings can be achieved (e.g., in brake repair) be examined. The intent of this evaluation, however, is to capture accurate

, known operations costs associated with the hybrid and

conventional vehicles for the selected period. This analysis is not pre dictive of maintenance costs assumed by UPS beyond the warranty period. The exact components and warranty periods

— as negotiated by UPS, Eaton

, and Freightliner

— are contractual and confidential

.

The hybrid and conventional vans all are still new enough that much of the maintenance is completed under warranty. All maintenance for the Eaton hybrid drive was done by Eaton

mechanics. These maintenance costs are not included in the maintenance

- cost analysis in this

section. Not accounting for warranty repairs in the evaluation of total maintenance cost does offer an incomplete picture of total maintenance cost. Even with out warranty costs, however, this analysis reflects the actual cost to UPS during the period selected.

M aintenance costs were collected in the sam e manner for each study group. All work orders and parts information available were collected for the study vans

. M aintenance practices are the same

for both the conventional and hybrid study groups. The maintenance analysis discussions include only the ma intenance data that were gathered during the evaluation period on the study group

vans

.16 Maintenance Costs This cost category includes the costs for parts and for labor at $50 per hour; it does not include

warranty costs. All costs related to an accident on a hybrid vehicle have been removed from this section as they do not represent the vehicle and powertrain comparison of interest

. Cost per mile

is calculated as follows :

Cost per mile = ((labor hours * 50) + parts cost)/m ileage

.

The labor rate has been set artificially at a constant rate of $50 per hour ; however, other analysts can change this rate to one more similar to their own situation . This rate does not directly reflect UPS’s current hourly mechanic rate.

Table 7 sh ows total and propulsion

- related maintenance costs for the two study groups. The propulsion

- related vehicle systems include the engine; transmission; electric propulsion; exhaust; fuel; and nonlighting electrical, which includes general electrical, chargin g, cranking, and ignition. The total maintenance cost per mile of $0.219 for the hybrid vans was 30% more than
the $0.168 for the conventional vans but was not statistically significant (P value = 0. 1128 ); total maintenance costs directly were only 6% grea ter. The propulsion

- related maintenance cost per

mile of $0. 074 for the hybrid vans was 77 % more than the $0. 042 for the conventional vans (P

value = 0.0 278 ) ; propulsion

- related costs directly were only 45 % greater

. However, because the

groups were running very different routes for most of the study with the hybrids accumulating far fewer miles per day

, maintenance costs are also considered on a cost

- per

- delivery

- day basis

. The total maintenance cost per day of $10.90 for the hybrid vans was 11% mor e than the $9.80

for the conventional vans. The propulsion

- related maintenance cost per day of $ 3.68 for the hybrid vans was 52 % more than the $2.4 3 for the conventional vans. The higher hybrid

maintenance cost s are drive n by more labor hours in most categ ories with transmission

- r elated hours being seven times higher than on the diesel vans. T he significantly fewer miles driven by the hybrids increases the cost per mile metric dramatically

. There was no statistically significant difference in group total ma intenance costs per month considered directly (P value = 0. 7334 ).

Table 7. Hybrid and Conventional Group Total and Propulsion Maintenance Costs

Study Group Miles Parts Cost Labor

Hours Maintenance

Cost Cost per

Mile ($/mile) Cost per Day ($/day)
Hybrid total 198,220 $12,703 613 $43,367 $0.219 $10.90
Hybrid propulsion

related 198,220 $2,779 237 $14,651 $0.074 $3.68

Conventional total 242,957 $17,934 458 $40,835 $0.168 $9.80

Conventional propulsion

- related 242,957 $2,336 156 $10,124 $0.042 $2.43

Included in the propulsion

- related maintenance cost data are exhaust diesel particulate filter ( DPF ) manual regenerations

, which are a large part of the propulsion maintenance costs for each

group

. In previous studies

, exhaust system

- related costs were neg ligible, but with these 2007

- certified engines the exhaust maintenance is a significant cost driven primarily by the new DPF

units and the need to manually regenerate them

.

Table 8 shows a breakdown by individual van of the total maintenance cost per mile

.17 Table 8. Hybrid and Conventional Van Total Cost per Mile

Total Maintenance Cost Comparison

Car Powertrain Mileage

Total Labor

Hours Parts Cost Cost ($/mile)

149765 Conventional 20,448 29 $878 $0.115

149772 Conventional 18,648 66 $1,426 $0.255

149777 Conventional 17,566 53 $1,097 $0.213

149779 Conventional 21,370 24 $2,363 $0.167

149780 Conventional 17,159 56 $1,954 $0.277

149783 Conventional 18,814 31 $363 $0.103

149784 Conventional 17,811 38 $1,590 $0.195

149831 Conventional 22,922 25 $1,552 $0.123

149832 Conventional 29,805 52 $2,813 $0.182

149833 Conventional 36,216 41 $2,628 $0.129

149871 Conventional 22,198 42 $1,270 $0.152

Total Conventional 242,957 458 $17,934 $0.168

144561 Hybrid 14,940 51 $373 $0.197

144564 Hybrid 17,067 42 $759 $0.169

144590 Hybrid 23,988 61 $1,843 $0.204

144594 Hybrid 17,663 35 $145 $0.106

144595 Hybrid 18,554 100 $1,419 $0.346

144596 Hybrid 14,757 41 $475 $0.170

144597 Hybrid 14,704 56 $1,425 $0.286

144598 Hybrid 16,024 62 $1,793 $0.305

144712 Hybrid 20,247 27 $1,128 $0.123

144719 Hybrid 19,456 80 $1,302 $0.274

144736 Hybrid 20,820 58 $2,041 $0.237

Total Hybrid 198,220 613 $12,703 $0.219

Table 9 shows a breakdown by individual van of the propulsion

- related maintenance cost per
mile.

Table 9

. Hybrid and Conventional Van Propulsion Cost per Mile

Propulsion Maintenance Cost Comparison

Car Powertrain Mileage

Total Labor

Hours Parts Cost Cost ($/mile)

149765 Conventional 20,448 11 $307 $0.042

149772 Conventional 18,648 25 $212 $0.078

149777 Conventional 17,566 22 $61 $0.066

149779 Conventional 21,370 7 $61 $0.018

149780 Conventional 17,159 29 $243 $0.098

149783 Conventional 18,814 6 $209 $0.027

149784 Conventional 17,811 12 $243 $0.048

149831 Conventional 22,922 8 $236 $0.027

149832 Conventional 29,805 12 $371 $0.032

149833 Conventional 36,216 8 $197 $0.017

149871 Conventional 22,198 17 $194 $0.047

Total Conventional 242,957 156 $2,336 $0.042

144561 Hybrid 14,940 21 $154 $0.082

144564 Hybrid 17,067 20 $253 $0.074

144590 Hybrid 23,988 36 $447 $0.094

144594 Hybrid 17,663 10 $124 $0.03418 Propulsion Maintenance Cost Comparison

Car Powertrain Mileage

Total Labor

Hours Parts Cost Cost ($/mile)

144595 Hybrid 18,554 19 $339 $0.070

144596 Hybrid 14,757 8 $136 $0.036

144597 Hybrid 14,704 23 $55 $0.083

144598 Hybrid 16,024 23 $187 $0.084

144712 Hybrid 20,247 8 $157 $0.027

144719 Hybrid 19,456 40 $234 $0.116

144736 Hybrid 20,820 29 $694 $0.103

Total Hybrid 198,220 237 $2,779 $0.074

Figure 11 shows monthly and cumulative total maintenance costs for the two study groups. The hybrid group started off costing more than the conventional group, but stayed level while the conventional group’s cost started lower and began to rise after 8 months of study.

Figure 11

. Total maintenance cost per mile19 Figure 1 2 shows monthly and cumulative propulsion

- related maintenance costs for the two st udy

groups

.

Figure 1 2

. Propulsion maintenance cost per mile20 Figures 1 3 and 1 4 show a breakdown of total and propulsion

- related maintenance costs per mile

for the conventional and hybrid study groups

, respectively

. For both groups note the high percentage of costs related to the exhaust system

, which is primarily related to manual regeneration of the DPF

.

Figure 1 3 . Propulsion maintenance cost per mile ( conventional vans )

Figure 1 4 . Propulsion maintenance cost per mile (hybrids)21 Total Cost per Mile

Table 10 shows a breakdown by individual van of the total cost per mile of operation . Fuel cost per mile dominated the total cost per mile for both groups, and the fuel cost per mile was a statistically significant 11 % less for the hybrid group (P value = 0. 0034 ). However, the greater hybrid maintenance cost s balanced out the fuel cost savings

. As such, total cost per mile was found not to be statistically significant (P value = 0. 9677 ). The average price for diesel was $3.58/gallon during this study period, and this figure was used to calculate fuel cost per mile.

Table 10 . Hybrid and Conventional Van Total Cost per Mile

Total Operating Cost Comparison

Car Powertrain Mileage

Total Non

- Prop

Maint ($/mile) Prop Maint ($/mile) Fuel Cost ($/mile) Total Cost ($/mile)

149765 Conventional 20,448 $0.073 $0.042 $0.406 $0.521

149772 Conventional 18,648 $0.177 $0.078 $0.425 $0.680

149777 Conventional 17,566 $0.147 $0.066 $0.457 $0.670

149779 Conventional 21,370 $0.148 $0.018 $0.387 $0.554

149780 Conventional 17,159 $0.178 $0.098 $0.385 $0.661

149783 Conventional 18,814 $0.076 $0.027 $0.415 $0.518

149784 Conventional 17,811 $0.147 $0.048 $0.416 $0.611

149831 Conventional 22,922 $0.096 $0.027 $0.420 $0.542

149832 Conventional 29,805 $0.149 $0.032 $0.398 $0.580

149833 Conventional 36,216 $0.112 $0.017 $0.381 $0.510

149871 Conventional 22,198 $0.105 $0.047 $0.398 $0.550

Total Conventional 242,957 $0.126 $0.042 $0.405 $0.573 *

144561 Hybrid 14,940 $0.115 $0.082 $0.395 $0.592

144564 Hybrid 17,067 $0.095 $0.074 $0.329 $0.498

144590 Hybrid 23,988 $0.110 $0.094 $0.328 $0.532

144594 Hybrid 17,663 $0.072 $0.034 $0.355 $0.461

144595 Hybrid 18,554 $0.277 $0.070 $0.348 $0.694

144596 Hybrid 14,757 $0.134 $0.036 $0.376 $0.545

144597 Hybrid 14,704 $0.203 $0.083 $0.413 $0.699

144598 Hybrid 16,024 $0.221 $0.084 $0.367 $0.672

144712 Hybrid 20,247 $0.096 $0.027 $0.373 $0.497

144719 Hybrid 19,456 $0.158 $0.116 $0.376 $0.649

144736 Hybrid 20,820 $0.134 $0.103 $0.306 $0.543

Total Hybrid 198,220 $0.152 $0.078 $0.359 $0.589 *

*not a statistically significant comparison at the 95% confidence level

Reliability As previously stated, some of the costs incurred by the vehicles were covered by in

- warranty repairs and possibly were not reported as part of this report

. Another measure of system reliability is the up

- time or availability of the vehicles

. UPS records in stances in which a vehicle

is not available to load in the morning as scheduled

. Scheduled maintenance events of any kind do not get re cord ed in this way , so only unscheduled maintenance is included

. During this 1 8

- month evaluation

, there were 380 operatio nal days available for deliveries for a total of 4

, 180 days for each study group of eleven vans

. The hybrid group missed substantially more days of operation than the conventional group (200 days vs. 13 days ) , especially during the first 3 months of the study

. Figure 15 shows the monthly and cumulative uptime for each group as a percentage of the total available delivery days

.22 Figure 15 . Cumulative u ptime

Batteries The Eaton system uses lithium ion batteries supplied by Hitachi for energy storage. The batteries have a capacity of 1.8 kWh and operate at a nominal voltage of 340 VDC

. These batteries and associated reliability data were not available to NREL during the evaluation period for detailed

evaluation

. The batteries are inc luded in the power electronics carrier shown in Figure s 3 and 4

. The s ervice l ife of the battery is estimated by Eaton a t more than 7 years

. 

### Laboratory Fuel Economy and Emissions Testing

T wo UPS delivery vehicles were tested on the chassis dynamometer at NREL's Renewable Fuels and Lubricants ( ReFUEL ) Research Laboratory . The remainder of this document includes the test plan and results from the v ehicle testing performed . The ReFUEL laboratory description, experimental setup, and test procedures are give n in the appendix.

Test Cycle Selection Figures 1 6 and 1 7 illustrate how the HHDDT, Hybrid Truck Utility Forum Class 4 ( HTUF4 ) and New York City Composite ( NYC Comp ) cycles compare to the observed daily in

- use fleet data. The selected cycles bracket the range of observed field data well on these and other metrics and

bracket the in

- field data on both the X and Y ax e s. Although the curve s created by these three cycles do not perfectly match the field data, they are the best fit available using standard duty cycles and considering all of the prioritized metrics, only some of which are shown here. The NYC Comp cycle is a bit more aggressive than most of the observed field data points from Minneapolis in regard to low average speed, high stops per mile, and high kinetic intensity ( KI )

,23 but this cycle represents a better hybrid scenario that may be available in other UPS fleet

locations

. Most of the observed field data point s fall around the HTUF4 cycle or between it and

the NYC Comp cycle

. The HHDDT cycle brackets the observed data on the more “ highway speed ”

- dominant end of the UP S in

- use data

.

Also, it is important to note the spread of hybrid and conventional vehicle data in the cloud of

observed f ield data. Half of the conventional vehicle data is clearly more highway oriented and less intense than the hybrid data

. The remainder of the conventional data is included with the hybrid data , again reinforcing the need for the route switch in the field analysis.

Figure 16 . Average driving speed and KI comparison24 Figure 17 . Stops per mile and KI comparison

**Selected Duty Cycle Description**

The NYC Comp duty cycle (Figure 18 ) represents “city” or urban driving commonly performed by medium

- and heavy

- duty commercial vehicles. The NYC Comp cycle is 1,030 seconds with an average driving speed of approximately 1 3 .1 mph and travels a distance of 2.5 miles with a KI

of 4.3 . This cycl e was determined to represent the most “urban” route observed during the drive cycle assessment of the UPS fleet and may be representative of typical routes in other cities . T he most “urban” driving of the field data collected shows most of the data below a KI of 3 and above 15 mph average speed

, so this cycle brackets the urban end of the spectrum.

Figure 18 . NYC Comp trace25 The HTUF4 duty cycle ( Figure 19 ) is a duty cycle lasting approximately 3,336 seconds with an average driving speed of approximately 22.5 mph and travels a distance of 11.2 miles with a KI of 1.51. This cycle was selected to represent the middle range of observed UPS operation in Minneapolis ; much of the field data collected is between 15 and 25 mph average speed with a KI

of 1 to 3

.

Figure 19 . HTUF Class 4 trace

The California Air Resources Board (CARB) HHDDT duty cycle (Figure 2 0 ) is a composite duty cycle developed to represent medium

- and heavy

- duty commercial vehicles. It consists of four segments: an initial idle segment (600 sec, average driving speed 0 mph), a creep segment (250 sec, average driving speed approximately 3 mph), a transient segment (650 sec, average driving speed approximately 18 mph), and finally, a highway segment (2,100 sec, average driving speed approximat ely 43 mph). The total cycle, which lasts 3,600 seconds, reaches a top speed of 59.3 mph and travels a distance of 26 miles with an average speed of 35.6 mph and a KI of 0.17. This cycle was selected to bracket the most “rural” or “highway” type operation

observed in the UPS Minneapolis fleet . T he most rural type of driving of the field data collected

shows most of the data are above a KI of 0 .7 and below 27 mph average speed.

Figure 2 0 . CARB HHDDT trace26 The test cycle statistics are shown in Table 11

. These test cycles bracket the in

- use GPS data discussed earlier with the NYC Comp cycle having slower speeds, more stops per mile

, and highest KI while the HHDDT cycle is more highway oriented with higher speeds and low stops per mile and KI

. HTUF 4 more closely matches the mid range of the GPS data.

Table 11

. Test Cycle Statistics and In

- F ield Average Comparison

Cycle Statistics Distance

Traveled

(miles) Average Speed o ver Cycle (mph) Average Driving Speed (mph) Maximum Speed (mph) Number of

S tops per

M ile Kinetic Intensity

(1/mi)

NYC Comp 2.5 8.8 13.1 36 8.0 4.30

HTUF4 11.2 12.1 22.5 56.5 2.5 1.51

CARB HHDDT 26.0 26.0 35.6 59.3 0.5 0.17

Hybrid Van

in

- field Data Range 16

– 86 3.3

– 13.2 11.4

– 2 7

. 1 38

– 79 2.2

– 9.1 0. 7

– 4.3

Conventional Van

in

- field Data Range 22

– 133 3.3

– 19.3 11.3

– 28.4 53

– 74 1.6

– 10 0. 6

– 4.4

Test Plan Tests were performed on one 2010 hybrid electric Workhorse P100 H delivery van and one

conventional 200 9 Workhorse P100 D delivery van during May and June 20 11 to determine emissions and fuel economy benefits of the hybrid electric powertrain being evaluated at UPS.

The 2009 conventional van is identical in specification to the 2010 conventional van s studied in Minneapolis, but was available closer to the labora tory test location

. The hybrid test vehicle was transported from the study group in Minneapolis for the laboratory testing. The tests were

conducted over the NYC Comp cycle

, the HTUF Class 4 cycle , and the CARB HHDDT cycle.

Vehicle exhaust emissions and fu el consumption were measured for repeated test conditions. All dynamometer sensors and instruments were monitored and recorded continuously by the ReFUEL data acquisition system throughout each test cycle run, unless otherwise noted.

Vehicle Specifications

Table 1 2 shows the test vehicle information. Vehicle test weights are different because the hyb r id system adds to the curb weight . E ach vehicle was loaded with the same amount of cargo weight (4

, 000 lbs)

.

Table 1 2 . Test Vehicle Information

Conventional P100D Hybrid P100H

Engine Cummins

ISB 07 (CM2150) Cummins

ISB 07 (CM2150)

Transmission Allison Auto HS 2200 Series Eaton Automated Manual

Gross Vehicle Weight Rating 23,000 lbs 23,000 lbs

Curb Weight 11,020 lbs 12,260 lbs

Test Weight 15,020 lbs 16, 26 0 lbs27 Conventional P100D Hybrid P100H

After Treatment DPF DPF

Fuel Diesel Diesel

Chassis Morgan Olson/Freightliner

P100D Utilimaster P100H

Laboratory Test Results All fuel economy and emissions results are averaged over four test runs of each cycle. Fuel economy results for the vans are shown in Table 1 3 and in Figure 2 1 with ± 95% confidence

interval error bars . The hybrid vans showed a 13 %

– 3 6 % improvement in fuel economy over the conventional vans on the tested duty cycles.

Table 1 3 . Fuel Economy of Hybrid and Conventiona l Van on Various Cycles on Chassis Dynamometer

Fuel Economy NYC Comp HTUF4 HHDDT

Conventional P100D (mpg) 6.8 7.5 9.6

Hybrid P100H (mpg) 8.8 10.1 10.8

Hybrid Advantage (%) 29% 36% 13%

t

- test P Value 0.0001 0.0000 0.0002

Figure 2 1 . Laboratory fuel economy28 Ton

- mi./gal fuel economy results for the vans are shown in Table 1 4 and in Figure 2 2 with ± 95%

confidence interval error bars . The hybrid vans showed a 21 %

– 45% improvement in fuel

economy over the conventional vans on the tested duty cycles.

Table 1 4 . Ton Fuel Economy of Hybrid and Conventiona l Van on Various Cycles on Chassis Dynamo m eter

Ton Fuel Economy NYC Comp HTUF4 HHDDT

Conventional P100D (ton

- mi./gal) 51.1 56.2 72.0

Hybrid P100H (ton

- mi./gal) 70.9 81.6 87.2

Hybrid Advantage (%) 39% 45% 21%

t

- test P Value 0.0000 0.0000 0.0001

Figure 22 . Laboratory ton

- mi./gallon fuel economy

Emissions results for oxides of nitrogen (NO

x ) are shown in Table 1 5 and in Figure 23 with

± 95% confidence interval error bars

. NO

x emissions increased on the hybrid on all cycles

, and the results were statistically significant

. The engines from both the hybrid and conventional vehicles were of the same engine family, model , model year

, U.S. Environmental Protection Agency ( EPA ) NO

x certification level

, and horsepower rating

. Heavy

- duty engines are certified

with the EPA engine certification test

, but are not certified with the completed hybrid configuration

. E ngine operation during a chassis dynamometer test is different than during the EPA engine certification test.

Table 1 5 . Average NO

x Emission Results of Hybrid and Conventional Vans on Specified Cycles

NOx Emissions NYC Comp HTUF4 HHDDT

Conventional P100D (g/mile) 6.8 5.2 3.2

Hybrid P100H (g/mile) 8.2 6.6 4.8

Hybrid Increase (%) 21% 28% 49%

t

- test P Value 0.0001 0.0001 0.000029 Figure 23 . Laboratory NO

x em issions

Emissions results for carbon dioxide (CO 2 ), total hydrocarbons (THC), carbon monoxide (CO), and particulate matter (PM) are shown in Table 1 6 and in Figures 24

– 27 with ± 95% confidence

interval error bars . Results that are not statistically significant at the 95% confidence level are in the gray areas. CO 2 emissions were consistently reduced on the hybrid as this is a measure of fuel consumption. Emissions of THC, CO

, and PM were all extremely low for both vehicles on all cycles

, and most differences were not statistically significant

.

Table 1 6 . Average Values for Emission Results of Hybrid and Conventional Vans on Specified Cycles

Comparison of Laboratory R esults to In

- Use Results The J1939 data logging devices used during the duty cycle stud y were also used during the dynamometer testing to assess the accuracy of their fuel economy measurement when used in the

field. Data logger

- derived fuel economy was consistently 6% higher on the conventional van and

11% higher on the hybrid van as compared to the in

- laboratory gravimetric measurements (as

described in the a ppendix) of those test runs ; therefore , these offsets were used to correct the

field data in the analysis below

. Also, zero

- speed fuel usage has been removed to eliminate the effect of high idle times observed in the field ( 30

- 55 % of the time for the conventional and Diesel Hybrid Hybrid

% diff P

Value Diesel Hybrid Hybrid

% diff P

Value Diesel Hybrid Hybrid

% diff P

Value

CO2

(g/mile) 1466 1143 -22% 0.000 1357 1008 -26% 0.000 1049 965 -8% 0.006

THC

(g/mile) 0.06 0.10 73% 0.027 0.00 -0.01 259% 0.58 0.00 0.02 942% 0.21

CO

(g/mile) 1.58 1.05 -33% 0.09 0.17 0.90 423% 0.000 0.20 0.14 -32% 0.38

PM

(g/mile) 0.0011 0.0009 -15% 0.82 0.0001 0.0003 272% 0.14 0.0003 0.0011 325% 0.26 NYC Comp HTUF 4 HHDDT30 hybrid van s) as compared to the relatively low idle times that are part of the three standard industry test cycles

.

Figure 24 shows a comparison of laboratory results to the corrected in

- use vehicle days and vehicle averages. The vehicle days show the wide daily variation in fuel economy while the vehicle averages generally fall in line with the laboratory tes ting results

— higher

- KI drive cycles result in lower fuel economy

. It is also clear that the hybrid group averages are more kinetically intense while half of the conventional group has lower KI averages than all the hybrids. Conventional van averages ranged from 4.9 to 9.1 mpg

, while hybrid van averages ranged from 8.2 to 10.4 mpg. In total

, 338 days of hybrid van operation and 252 days of conventional van operation on eight vans from each group were doc umented and are displayed in this figure.

Figure 24 . Laboratory and in

- use f uel economy results

Status of UPS Hybrid Fleet

UPS was satisfied with the performance of the original 50 (prototype) hybrid electric vans over the first year of service

, which is documented in 12

- and 36

- month NREL technical reports

. 3

UPS ordered and has taken delivery of an additional 200 second

- generation hybrids with

additional features

, including “ engine off at idle ” ; this report documents those updates

.

3 http://www.nrel.gov/vehiclesandfuels/fleettest/research_hybrid_ups.html31 

### Conclusions

• C umulative miles per van for the hybrids were 33% less than the conventional group during the complete 18

- month study. The hybrid group accumulated miles at a slower rate than the conventional group during the 13 months of the original route assignments,

bu t at a faster rate than the conventional group for the 5 months after the route switch.

• The study groups were on significantly different duty cycles

, necessitating a route switch between the groups to more accurately compare fuel economy and maintenance co sts.

• Fuel economy before and after the route switch during equal 5

- month periods from different years on a route assignment was considered.

o “Conventional

, ” lower

- KI route analysis: Fuel economy of the hybrid group on the original c onventional route assignments over 5 months was 10.4 mpg , or 13% greater than the 9.2 mpg of the conventional group on those routes a year earlier

.

o “Hybrid

, ” higher

- KI route analysis: Fuel economy of the hybrid group on the original hybrid route assignment s over 5 months was 9.4 mpg , or 20% greater than the 7.9 mpg of the conventional group on those routes a year later

.

o The difference in hybrid advantage in fuel economy is as expected

. The hybrids demonstrated a greater advantage on more urban, low speed, high stops

- per

- m ile route assignments and lower advantage on route assignments with a longer highway leg and less dense delivery zones.

• T otal maintenance cost per mile was 30 % higher for the hybrids

, but was not statistically significant ( P value = 0. 1128 )

. However, this was only 1 1 % more when considered on a

cost

- per

- delivery

- day basis.

• Propulsion

- related maintenance cost per mile was 77 % higher for the hybrids ( P value =

0.0 278 ). However, this was only 52 % more when considered on a cost

- per

- delivery

- day

basis.

• Fuel costs per mile (assuming $3.58/gal) for the hybrids were 11% less than those for the

conventional vans (P value = 0.0034).

• Total operating costs per mile (assuming $3. 58 /gal) for the hybrids were not found to be statistically significant (P value = 0. 9677 ).

• The hybrid group had a cumulative uptime of 92.5% compared to the conventional group uptime of 99.7%.

• Laboratory testing demonstrated 13% to 36% increase in fuel economy for the hybrid.

• Laboratory testing demonstrated 21% to 45% increase in ton

- mi/ gal for the hybrid.

• Laboratory testing demonstrated an increase in NO

x emissions of 21% to 49% for the hybrid.32 

### Contacts

U.S. Department of Energy Energy Efficiency and Renewable Energy Vehicle Technologies Program

Lee Slezak Manager, Advanced Vehicle Testing Activity

Phone: 202

- 586

- 2335

E

- mail: lee.slezak@ee.doe.gov

National Renewable Energy Laboratory

Mike Lammert Project Engineer

Phone: 303

- 275

- 4067

E

- mail: michael.lammert@nrel.gov

Kevin Walkowicz Advanced Vehicle Testing Activity Lead

Phone: 303

- 275

- 4 492

E

- mail: kevin.walkowicz @nrel.gov

United Parcel Service

Mike Britt

Director of Maintenance & Engineering, Ground Fleet

Phone: 404

- 828

- 4661

E

- mail: mbritt@ups.com

James C. Francis UPS Engineering

- Area Automotive Manager, Northern Plains District

Phone: 612

- 379

- 6610

E

- mail: jcfrancis@ups.com

Eaton Corporation Alex Stuckey Special Projects Engineering

Phone: 269

- 342

- 3105

E

- mail: AlexBStucky@Eaton.com33 

### Appendix: Laboratory Description and Test Methods

General Lab Description

The vehicles were tested at the Renewable Fuels and Lubricants ( ReFUEL ) L aboratory, which is operated by the National Renewable Energy Laboratory ( NRE L ) and located in Denver,

Colorado

. The lab includes a heavy

- duty vehicle (chassis) test cell and an engine dynamometer test cell with emissions measurement capability

. Regulated emissions measurements are performed using procedures consistent with SAE J2711

. Instrumentation and sensors at the laboratory are maintained with Nat ional Institute of Standards and Technology (NIST)

- traceable calibration. Test procedures, calibrations, and measurement accuracies are maintained to meet

the requirements outlined in the current Code of Federal Regulations ( CFR ) T itle 40, S ection 86,

S ubpart N . D ata acquisition and combustion analysis equipment are used to measure vehicle performance and emissions

. Other capabilities of the laboratory include systems for sampling and analyzing unregulated emissions, on

- site fuel storage and fuel blendin g equipment, high

speed data acquisition hardware and software to support in

- cylinder measurements, and fuel ignition quality testing

. Instrumentation and sensors at the laboratory are maintained with NIST

traceable calibration.

Chassis Dynamometer

The ReF UEL laboratory’s chassis dynamometer is installed in the main high

- bay area of the laboratory. The roll

- up door to the high bay is 14 ft x 14 ft , high enough to accept all highway

ready vehicles without modification

. The dynamometer is installed in a pit b elow the ground level, such that the only exposed part of the dynamometer is the top of the 40

- in.

- diameter rolls. Two sets of rolls are installed, so that twin

- axle tractors can be tested. The distance between the

rolls can be varied between 42 in. and 56 in. The dynamometer will accommodate vehicles with

a wheelbase between 89 in. and 293 in. The dynamometer can simulate up to 80,000

- lb vehicles at speeds up to 60 mph.

The chassis dynamometer, illustrated in Figure A

- 1 is composed of three major componen ts: the

rolls

, which are in direct contact with the vehicle tires during testing ; the direct current electric motor (380 hp absorbing/360 hp motoring) dynamometer ; and the flywheels

.

The rolls are the means by which power is absorbed from the vehicle

. The rolls are attached to gearboxes that increase the speed of the central shaft by a factor of 5. The flywheels, mounted on the back of the dynamometer, provide a mechanical simulation of the vehicle inertia.

The electric motor is mounted on trunnion bearin gs and is used to measure the shaft torque from the rolls. The energy absorption capability of the dynamometer is used to apply the “ road load ,” which is a summation of the aerodynamic drag and friction losses that the vehicle experiences in use, as a function of speed. The road load may be determined experimentally if data are available or estimated from standard equations

. The electric dynamomet er is also used to adjust the simulated inertia, either higher or lower than the 31,000

- lb base dynamometer inertia, as the test plan requires. The inertia simulation range of the chassis dynamometer is 8,000

– 80,000 lb. The electric motor may also be used to simulate grades and provide braking assist during

decelerations.

The test vehicle is secured with the drive axles over the rolls

. A driver’s aid monitor in the cab is used to guide the vehicle operator in driving the test trace

. A large fan may be used to cool the34 vehicle radiator during testing. The chassis dynamometer is supported by 72 channels of data acquisition in addition to the emissions measurement, fuel metering, and combustion analysis subsystems

.

The dynamometer is capable of simulating veh icle inertia and road load during drive cycle testing . When the vehicle is jacked up off the rolls, an automated dynamometer warm

- up procedure is performed daily, prior to testing, to ensure that parasitic losses in the dynamometer and gearboxes have stabi lized at the appropriate level to provide repeatable loading

. An unloaded

coast

- down procedure is also conducted to confirm that inertia and road load are being simulated by the dynamometer control system accurately

. Between test runs

, a loaded coast

- down procedure is performed to further ensure the stability of vehicle and dynamometer parasitic losses and accurate road load simulation during testing.

Figure A

- 1

. Chassis d ynamometer s chematic

Fuel Storage and Blending There are buildings designed specif ically for safely storing and handling fuels at the ReFUEL facility. The fuel storage shed is 8 ft x 26 ft and holds up to 48 drums (55 gal. each). Features include heating/cooling, secondary containment to 25% of capacity, continuous ventilation, explosio n

- proof wiring/lighting, and a dry chemical fire suppression system.

The fuel blending shed is 8 ft x 14 ft and has a nominal storage capacity of 24 drums. It has all of the features of the storage shed plus explosion

- proof electrical outlets for powering accessories. The fuel blending can be performed on a gravimetric or volumetric basis, with capability for both large

- (L/kg) and small

- scale (cc/g) measurements.

A fuel line inside a sealed conduit delivers the fuel from the supply drum to the fuel

meter ing/conditioning system inside the ReFUEL laboratory, eliminating the need for bulk fuel storage inside the laboratory. Another fuel line in the same conduit delivers waste fuel back to the fuel blending shed for storage (waste fuel is generated only when a fuel changeover requires a flush of the system).35 Fuel Metering and Conditioning The fuel metering and conditioning system (Figure

A

- 2 ) supports test work for both the engine and the chassis dynamometers. The meter measures

volumetric flow to an accura cy of ±0.5% of the reading, with a manufacturer’s stated reproducibility

of 0.2%. An in

- line sensor measures the density with an accuracy of ±0.001 g/cc, allowing an accurate mass measurement over the test cycle even if the density of

the fuel blend is not known prior to testing.

Air Handling and Conditioning Dilution air and the air supplied to the test engine or vehicle for combustion are derived from a common source, a roof

- mounted system that conditions the temperature of the air and humidifies as needed to meet desired specifications . The system can also pressurize the incoming air to simulate sea level combustion. This gives the lab the ability to simulate any altitude between sea

level and 5

, 280 feet. This air is passed through a HEPA filter, in accordance with 2007 CFR specifications, to eliminate background particulate matter as a source of uncertainty in particulate

measurements

. The average inlet air temperature to the vehicle is maintained within a window of

75 ° F ± 4 ° F f or all test runs

, and average humidity is controlled to 75 grains/lb (absolute) ± 4 grains/lb.

Emissions Measurement The ReFUEL Laboratory’s emissions measurement system supports both the engine and chassis dynamometers. It is based on the full

- scale exhaust dilution tunnel method with a constant volume sampling system for mass flow measurement. The system is designed to comply with the requirements of the 2007 version of 40 CFR 86 S ubpart N. Exhaust from the engine or vehicle

flows through insulated piping to the full

- scale 18

- in. diameter stainless steel dilution tunnel. A static mixer ensures thorough mixing of exhaust with conditioned, filtered, dilution air prior to sampling of the dilute exhaust stream to measure gaseous and par ticulate emissions.

A system with three venturi nozzles (Figure A

- 3 ) is employed to maximize the flexibility of the emissions measurement system. Featuring 500

- cubic foot per minute (cfm), 1

, 000

- cfm, and 1

, 500

- cfm venturi nozzles and gas

tight valves, the system flow can be varied from 500 cfm to

3

, 000 cfm flow rates in 500

- cfm increments

.

This allows the dilution level to be tailored to the engine size being tested (whether on the engine stand or in a vehicle), maximizing the accuracy of the emissions measurement equipment.

The gaseous emissions bench is a Pierburg model AMA

- 2000 (Figure A

- 4

, center). It features continuous analyzers for THC, NO

x , CO, CO 2 , and oxygen . The system also features auto

ranging, automated calibration, zero check, and span check features as well as integrating functions for calculating cycle emissions. It communic ates with the ReFUEL data acquisition systems through a serial interface. Figure A

- 2 . Pierburg fuel metering system

Figure A

- 3 . Venturi nozzles36 There are two heated sample trains for gaseous

emissions measurement: one for HC and another for the other gaseous emissions. NO

x and HC measurements are performed on a wet basis, while CO, CO 2 and oxygen are measured on a dry basis. Sample probes are located in the same plane in the

dilution tunnel

.

The particulate matter sample control bench, shown in Figure A

- 4 , is managed by the ReFUEL data acquisition system through a serial connection. It maintains a desired sample flow rate through the particulate matter (PM) filters in proportion to the

overall constant volume sampling flow, in accordance

with the CFR

. Stainless steel filter holders , designed to the 2007 CFR requirements (Figure A

- 5

, center),

house 47

- mm

- diameter Teflon membrane filters through which the dilute exhaust sample flows

. The PM sampling system is capable of drawing a sample directly from the large full

- scale dilution tunnel or utilizing secondary dilution to achieve the desired temperature, flow, and concentration

characteristics

. A cyclone separator, as described in the CFR requirements, is employed to mitigate tunnel PM artifacts.

A dedicat ed clean room/environmental chamber (Figure A

- 5 , left) is inside the ReFUEL facility. It is a Class 1000 clean room with precise control over the temperature and humidity (±1°C for temperature and dew point). This room is used for all filter handling, cond itioning, and weighing.

The microbalance (Figure A

- 5 , right) for weighing PM filters has a readability of 0.1 μg (a CFR requirement) and features a barcode reader for filter identification and tracking and a computer interface for data acquisition. The microbalance is installed on a specially designed table to

eliminate variation in the measurement due to vibration. The microbalance manufacturer (Sartorius) was consulte d on the design of the clean room, to ensure that the room air flow would be compatible with the microbalance. Figure A

- 5. Class 1000 clean room, filter housing

, and microbalance Figure A

- 4 . Emissions bench