NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

HTUF 2009

Fleet Experience and 

Needs Session

Kevin Walkowicz

National Renewable Energy 

Laboratory

Advanced Vehicle Testing Activity

October 28, 2009

NREL/PR-540-46995

NREL & DOE Activities: Update
National Renewable Energy Laboratory Innovation for Our Energy Future

MD & HD Hybrid Fleet Testing at NREL 

• Funded Through DOE’s Vehicle Technology 

Program 

• Goals/Objectives:

• Real-world feedback: new technology vs conventional (under 

same conditions)

• 6-12 month, on-road evaluations 

• Obtain and analyze data: – Operating cost/mile – Fuel economy – Maintenance costs – Warranty issues – Reliability (miles between failure) – Implementation issues from a fleet’s perspective – Duty cycle analysis – Subsystem performance

• Provide data to help fleets, manufacturers and other R&D 

organizations who might be considering similar technology – Publish data – Acquire data for vehicle modeling activities – Identifies additional barriers to energy efficient 

vehicles
National Renewable Energy Laboratory Innovation for Our Energy Future

Recent Projects: Fed Ex (DOE, CALSTART, SCAQMD)

• Azure HEV Delivery Vehicles

• Status: Dyno testing and on-road evaluation -

April 2009 thru April 2010

• Technology: Azure Gen I gasoline HEV in 

Southern CA vs conventional diesels

• Data: Interim report in late 2009, Final report in mid 

2010; Include both on-road and chassis dyno data

• Results: 

Chassis Dyno Data:

• MPG: -2 to +20 % improvement in MPG (dge) 

(gasoline engine vs diesel)

• Emission Reductions:

• Much cleaner!

• NOx = 75-89%

• PM = 99.9%

Drive 

Cycle

gHEV FE

(mpg)

gHEV Diesel 

Equivalent FE

(mpg)

Diesel FE

(mpg)

Energy 

Content Adj

GHEV 

Advantage

HTUF4 10.45 11.36 11.66 -2.6%

OCTA Bus 8.61 9.36 9.52 -1.7%

NYCC 6.75 7.34 6.08 +20.7%
National Renewable Energy Laboratory Innovation for Our Energy Future

Recent Projects: UPS

• Eaton Hybrid Delivery Vehicles

• Status: Dyno testing and on-road 

evaluation began in 2008. Now 

complete.

• Technology: Gen I diesel HEV inuse in Phoenix, AZ vs conventional 

diesels

• Data: Final report in Nov 2009 will 

include on-road eval + chassis dyno

data

• Results:

• 29% on-road fuel economy 

improvement for hybrids

• 31-37% improvement in-lab 

(CILCC/CBD/WVU City)

• Diesel = $0.53 per mile operating 

costs

• Hybrid = $0.43 per mile operating 

costs

UPS Fuel Economy Comparison

Monthly Average and Cummulative

8

10

12

14

16

Jan

08

Feb

08

Mar

08

Apr

08

May

08

Jun

08

Jul 08 Aug

08

Sep

08

Oct

08

Nov

08

Dec

08

Miles per gallon

Diesel group Hybrid Group

Diesel Cummulative Hybrid Cumulative

13.1 mpg

10.2 mpg
National Renewable Energy Laboratory Innovation for Our Energy Future

Recent Projects: PHEV School Bus

• PHEV School Bus / Enova-IC Corp

• Status: Dyno testing and on-road 

evaluation completed for 4 sites (Austin, 

Napa, Wake County NC, Manatee FL)

• Technology: Diesel Plug-In HEV 

(Enova charge-depleting) school buses 

in-use in various locations 

• Data: Final report in Dec 2009

• Results: 

• 44-113% improvement in CD

• But...3-39 miles possible in CD

• Slight improvement in CS

• On-road MPG: 

• 6.5-7.1 mpg diesels

• 8.0-9.1 mpg hybrids

• Good reliability and low 

maintenance costs

8.8

7.3

9.8

6.1

5.1 4.8

5.8

5.0 4.6

6.1

4.7

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

11.0

12.0

UDDSHDV, hot RUCSBC, hot OCTA, hot

MPG

Cycle Tested

Laboratory Fuel Economy

PHEV Charge Depleting PHEV CS (Corrected)

Baseline Diesel "PHEV w/hybrid off"
National Renewable Energy Laboratory Innovation for Our Energy Future

FY10 Planned Projects: More Hybrids!

• Recently announced DOE funded grants (still under negotiation):

• Navistar: Expanded, next-gen PHEV school bus 

• SCAQMD: 378 trucks and shuttle buses with Eaton

• Navistar: 400 EV Delivery Trucks

• Smith Electric: ~100 Transit Connect EV and ‘Newton’ MD trucks

• FY10 Evaluations and Interests (being planned now thru DOE’s 

Vehicle Technologies Program):

• Class 7-8 HEV

• Day Cab HEV tractors

• Lithium battery buses - various locations, in-depth battery data

• Next generation, improved HEV systems for MD Package Delivery

• Plug In Hybrid Trucks

• Hydraulic Hybrids
National Renewable Energy Laboratory Innovation for Our Energy Future

Key Findings & Considerations

• Business Case and Payback?

• Duty Cycle drives fuel use and % 

improvement

• The ‘most urban’ route not always best 

place for HEV’s and other advanced 

technology vehicles

• Fuel Price Driven

• Green Initiatives?

• CO2 Credits / Cap & Trade

• Future of Hybrids – Market 

Penetration?

• Depends on Fuel Prices, hardware 

costs (battery costs), incentives

0 10 20 30 40 50 60

WVUINTER

CBDTRUCK

COMMUTER

WVUSUB

Transit Bus

Local

ARTERIAL

CILCC

CSHVR

WVUCITY

Drive Cycle

Percent Improvement in Fuel Economy by HEV
National Renewable Energy Laboratory Innovation for Our Energy Future

For More DOE / NREL MD&HD Hybrid Info

Lee Slezak

U.S. Dept of Energy

Vehicle Technology Analysis & Evaluation Program Manager 

Vehicle Technologies Program

Lee.slezak@ee.doe.gov

202-586-2335

Kevin Walkowicz

National Renewable Energy Laboratory

Advanced Vehicle Testing Activity Team Lead

kevin.walkowicz@nrel.gov

phone: 303.275.4492