Daimler Trucks and Buses 1 

Super Truck Program: Vehicle Project Review

Recovery Act –Class 8 Truck Freight Efficiency 

Improvement Project

Project ID: ARRAVT080

This presentation does not contain any proprietary, confidential, or otherwise restricted information

Derek Rotz (PI & Presenter)

Dr. Maik Ziegler

Daimler Truck North America LLC

June 19th

, 2014
Daimler Trucks and Buses 2 

Overview

• Project start: April 2010

• Project end: March 2015

• Percent complete: 80% 

• Resolve thermal & fluid dynamics tradeoffs between aero 

& cooling

• Rejecting more heat in a smaller, aerodynamic hood & 

engine compartment

• Development of safe and efficient high voltage power 

distribution, integrating multiple HV energy sources

• Making tradeoffs between efficiency, cost and weight

• Vehicle controls integration (aux, hybrid, powertrain, 

waste heat, predictive) 

Timeline

Budget

Barriers

Partners

• Total project $79,119,736

• Vehicle budget $47,486,735

– DOE share(*) $15,526,639

– DTNA share (*) $ 15,526,639

(*) through Feb, 2014 for vehicle R&D expenses only, engine R&D expenses 

reported separately

• Detroit Diesel

• Schneider National, Walmart

• National Renewable Energy Lab

• Oregon State University

• Strick Trailer

• Michelin

• ... 
Daimler Trucks and Buses

Objectives and Milestones

Timeline Phase Description Milestones 

4/10–3/11 Analysis:

(1) Technology Modeling/Analysis and Initial 

Component Development and Demonstration

Develop analytical roadmap:

• 50% vehicle freight efficiency improvement

• 50% engine brake thermal efficiency 

4/11–3/12 Specification:

(2) Experimental Demonstration of Technology

Building Blocks for Intermediate Goals

Experimentally demonstrate technology building blocks:

• 25% vehicle freight efficiency improvement (system level test)

• 46% engine brake thermal efficiency

4/12–5/13 Design:

(3) Technology Identifications and Final 

Component Development and Demonstration

Identify and initially develop technology building blocks:

• 50% vehicle freight efficiency improvement (system level test & analysis)

• 50% engine brake thermal efficiency 

6/13–6/14 Build: 

(4) Experimental Demonstration of Technology 

Building Blocks for 50% Engine Thermal 

Efficiency and 50% Vehicle Efficiency

Experimentally demonstrate technology building blocks:

• 50% vehicle freight efficiency improvement (system level test)

• 50% engine brake thermal efficiency 

7/14–3/15 Test:

(5) Final System Integration and Demonstration

Experimental demonstration:

• 50% vehicle freight efficiency improvement (entire vehicle test)

• 50% engine brake thermal efficiency (engine test)

• 55% engine brake thermal efficiency (engine analysis)

3 

Develop and demonstrate a 50% total increase in vehicle freight efficiency: • At least 20% improvement through a heavy-duty diesel engine capable of achieving a 50% brake-thermal efficiency

• Identify key pathways towards achieving 55% through modeling and analysis

Objectives/Relevance
Daimler Trucks and Buses

Phase I Milestone Completed 

Analytical roadmap development to 50% vehicle FEI & 50% engine BTE

4 

Baseline Tractor

•2009 Cascadia 125”BBC, 72”RR

•DD15 Engine 455hp/1550 lb-ft

Vehicle Test

•Baseline Peformance Measurements

•Highway Cycle (55 &65 mph)

•Idle Cycle (summer, winter)

•City Cycle

SuperTruck

Modeling & Analysis

•Establish System Level Technical Targets

 Roadmap: Vehicle Roadmap: Engine

Approach

(Engine topics covered in separate session)
Daimler Trucks and Buses

0.0

5.0

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

55.0

5 

(to 48.1% BTE)

(incl. idle reduction)

(Scale WT)

Phase 2 & 3 Milestone Status 

Experimental testing to 25% & 50% vehicle freight efficiency*

Freight Efficiency Improvement % - (system level measurements)

50.0

Engine

14.5%

Parasitic

Losses

1.0%

Energy

Management

3.5%

Lightweight

5.0%

Powertrain

Drivetrain

Aerodynamics

16.0%

Tractor

Trailer

16.5%

2.4%

(incl. hybrid)

Approach

* Technical Accomplishments covered in the 2012-2013 Annual Merit Reviews
Daimler Trucks and Buses

Phase 4: Road to 50% 

2009 Baseline Cascadia 6 

Approach

A-Sample

A-Sample

• Aero hood, bumper, grille

• Downsized Engine, Automated Manual Trans. + eCoast

• Waste Heat Recovery (electrical expander & vehicle cooling)

• 6x2 Axle Tall RAR + oil management

• Hybrid Electric Powertrain (120kw eMotor, 360v, 2.4 kw-hr usable Li-Ion Bat)

• eHVAC (HV compressor, remote condensor, electrical fan)

• eMotor engine start

• Cab insulation package

• Clutched air compressor 

• Electronic air control

• AccuSteer 

• Low RR wide based single tires

• Thermal management

• Trailer aero., lightweighting and solar

2009 Baseline Cascadia

Final Demonstrator
Daimler Trucks and Buses

A-sample SuperTruck Build

Testing completed to date:

 Full Scale Wind Tunnel (underhood airflow)

 eMotor cold start

 Thermal tunnel test

 eHVAC test & calibration

 Vehicle Performance Testing

Purpose: to prototype a functional chassis to integrate 

vehicle systems: 

  Downsized Engine, Waste Heat, Hybrid, Cooling

  High Voltage Power Distribution

  Powertrain/Drivetrain Integration

  Software integration e.g. Shift optimization

  Packaging, Routing & Plumbing etc.

7 

Technical Accomplishments A-Sample Truck
Daimler Trucks and Buses

Waste Heat Recovery Status

Accomplishments

• Successful Key-on workshop in November including HV 

electrical components

• 6kw peak exhaust energy recovered under high load, 

steady state conditions

Current Tasks

• Develop de-aeration strategy 

• Improve control stability during transient operation

8 

Technical Accomplishments A-Sample Truck
Daimler Trucks and Buses

A-Sample Thermal Tunnel Testing

Vehicle Measurements

Ambient Capability Engine + Waste Heat

• 113°F (45°C) reached

Engine Air Intake

• Stayed below temperature rise limits

• Pressure measurements noisy

Fan Speed Characterization

• Swept temperatures (25-40°C)

• Swept wind speeds (20-40mph) 

• Grille open & closed positions

• Fan speed remained below 1000 RPM

9 

Technical Accomplishments A-Sample Truck
Daimler Trucks and Buses

A-Sample Air Flow Study in Wind Tunnel

Vehicle Measurements

Cruise Speed (58mph) Air Flow (kg/ s) Drag

A-sample configuration Eng, WHR, CAC ΔCd (0° Yaw)

 Nominal baseline baseline

 Cooling optimized grille +3% 0%

 Aero optimized grille -57% -6%

SuperTruck Program 10

Technical Accomplishments A-Sample Truck
Daimler Trucks and Buses

eMotor Cold Start Test

Vehicle Measurements

Test Procedure

• 24 hour cold soak

• 0 to -15°C by 5° incr.

Observations

• No eMotor torque increase at lower temps.

• Peak Li-ion battery current at 112A

Conclusions

• Temperatures of -15°C easily achievable

• Data indicate -20 to -25°C starting possible

• >1% Freight Efficiency gained

• Omit starter and Pb-Acid starting batteries

11

Technical Accomplishments A-Sample Truck
Daimler Trucks and Buses

Vehicle Level Performance Test 

March-April, 2014: On Highway Fuel Economy Test

12

Technical Accomplishments A-Sample Truck

 Gross Vehicle 

Weight (lb) 

Total 65,000 

Tare 34,000

Payload 31,000 

Gross Vehicle 

Weight (lb) 

Total 65,000 

Tare 32,450

Payload 32,550 

0

4

8

12

3/26 3/27 3/31 4/1 4/8 4/9 4/10

Fuel Economy (mpg) 

 PCP SDS

Daily Fuel Economy

A-Sample Baseline

1550 lbs. additional freight on A-Sample  5% Freight Efficiency Improvement 

52.0%

61.6% 5.0%

5.0%

PCP SDS

A-Sample % improvement 

(ton-mpg)

Freight Efficiency Improvement 

(measured)

Fuel Weight

57% 66% 

Grade Profile

San Antonio Dallas (SDS)

65 mph

Portland Canyonville (PCP)

Grade Profile

55 mph
Daimler Trucks and Buses

2009 Baseline Cascadia

Final Demonstrator

Final Demonstrator

A-Sample Technologies, plus...

• Full Tractor Aero 

• 50% BTE Engine + WHR

• Predictive hybrid & engine controllers

• Axle - Active oil management with FE gear oil

• Lightweight Aluminum Frame and cross members

• Ultra Lightweight Air Suspension

• Smart 6x2

• Solar reflective paint

• Enhanced Trailer aerodynamics

Phase 4: Road to 50% 

 13

Approach

2009 Baseline Cascadia

A-Sample
Daimler Trucks and Buses

Aerodynamics Validation in Scale Model Wind Tunnel

SuperTruck vs. Baseline

14

Tractor

67% 

Trailer 

33%

Percentage of 

Test Runs

Tractor

ΔCd 

-15% 

Trailer

ΔCd -

39% 

Drag Reduction 

Contribution

Technical Accomplishments Final Demonstrator
Daimler Trucks and Buses

Final Demonstrator Build

Cab Interior

• Sleeper design complete

• Components & assy. ongoing

• Ship to Portland in June

Cab Exterior

• Design release complete incl. A&B 

side parts

• Molds & exterior parts 80% complete

• Pre-fit completed by June

Chassis

• Frame, Suspension, Axles complete

• Powertrain & cooling Installed

• Wiring & plumbing on-going

Build progressing for Sept 1st FE test start

15

Technical Accomplishments Final Demonstrator
Daimler Trucks and Buses

SuperTruck Partnerships and Collaborations

16

Collaborations/Partnerships

Energy Management

Lightweighting

Aero/Cooling

Fleet

Hybrid

Powertrain/Parasitics

Engine

Transmission

Trailer

Department of Energy:  Roland Gravel  Ken Howden

 Gurpreet Singh  Carl Maronde
Daimler Trucks and Buses

Summary and Future Work

Successful completion of phases 1-3; Phase 4 targets met

50% Vehicle Freight Efficiency target exceeded on A-Sample vehicle through testing 

on Portland-Canyonville and San Antonio-Dallas routes

50% Engine Brake Thermal Efficiency target exceeded in engine test cell

Next Steps

• Complete buildup of 2 final 

 demonstrator vehicles

• Conduct fuel economy testing

17

Summary/Future Work
Department 

Backup

18
19 Daimler Trucks and Buses

Project Year 4 (PY4) Engine BTE Improvement  2.1% 

points

 PY4 Enablers

 Further increase in compression 

ratio (CR), piston bowl and matching 

injector profile optimization.

 3rd Iteration of turbo-charger.

 Optimized liner cooling.

 EGR waste heat recovery.

 WHR component and calibration 

optimization. 46.8%

47.9%

1.3%

2.3%

PY3 PY4

Brake Thermal Efficiency 

Engine WHR

48.1%

50.2%

Backup