Nic Lutsey

El Monte, California

May 18th, 2010

Survey of vehicle mass-reduction 

technology trends and prospects 
Outline

• Introduction: CO2reduction technologies

• Vehicle mass-reduction technology

– Mass-reduction techniques

• Background, advanced materials, components, designs

– Potential for future designs

• Prototypes, concepts

• Objective

– Highlight emerging mass-reduction technology trends

– Examine the technology potential for the 2025 timeframe

This a presentation based on the following report:

Lutsey, N., 2010. Review of technical literature and trends related to automobile mass-reduction 

technology. Institute of Transportation Studies, University of California, Davis, UCD-ITS-RR-10-10. 

http://pubs.its.ucdavis.edu/publication_detail.php?id=1390
CO2

− equivalent

emissions

(g/ mi)

 

 

 

  

 

 

 

  

= CO2+ N2O+ CH4− MACallowance

Vehicle GHG emissions

Carbon dioxide 

(CO2)

CO2

HFC

A/C compressor

Engine

Transmission

Nitrous Oxide

Black carbon

Methane
* Many technologies can be combined, but percents are not strictly additive; 

Estimations are based on primarily on US EPA/NHTSA, 2010; # From US EPA, 2009 

“Trends”report

GHG-Reduction Technologies

Area Technology or mechanism for CO2 reduction Potential CO2

reduction *

U.S. adoption in 

2008 fleet #

Variable valve timing or lift 2-8% 53%

Cylinder deactivation 3-6% 6%

Turbocharging 2-5% 2%

Engine Gasoline direct injection 8-15% 4%

Compression ignition diesel 15-40% 0.1%

Powertrain Digital valve actuation 5-10% 0%

Homogeneous charge compress. ignition 15-20% 0%

6+ speed 3-5% 21%

Transmission Continuously variable 4-6% 8%

Dual-clutch, automated manual 4-8% 1%

Aerodynamics 5-8% -

Tire rolling resistance 2-8% -

More efficient auxiliaries (steering, air conditioning) 2-10% -

Vehicle Mass-reduction Advanced material component 5-10% -

Integrated vehicle design 10-20% -

Hybrid systems Stop-start mild hybrid 5-10% <1%

Full hybrid electric system 20-50% 2%

Electric-drive Plug-in capable electric vehicles 30-75% 0%

Fuel cell vehicles 30-75% 0%

Critical nearer te

CO2reduction 

technologies

Critical medi

and long-te

CO2reducti

technologie

• There are many promising CO2-reduction technologies for vehicles

• Vehicle design and electric-drive technologies could be increasingly critical
Approximately based on U.S. city and highway drive cycles (Kromer and Heywood, 2008); in addition to inertial 

mass and rolling resistance hill-climbing is also directly linked to vehicle mass, percent vehicle energy use and 

loss vary greatly according to vehicle technology and drive cycle. 

Background: Mass and CO2 emissions

• Vehicle mass is fundamental part of vehicle CO2 emissions

– Efficiency is the ability of a powertrain to convert energy into vehicle propulsion

– The ultimate vehicle “road load”is tied directly to the vehicle mass

– Reduction in mass ‡ reduction in required energy ‡ reduction in CO2 emissions

CO2
Sources: Casadei and Broda, 2008; Bandivadekar et al, 2008; FKA, 2007; Pagerit, et al, 2006. Effects 

differ by drive cycle (greater effect in city/urban, lesser effect in highway conditions)

Background: Mass and CO2 emissions

• Mass has a large effect on vehicle CO2 emissions

– With vehicle mass-reduction technology, CO2 emissions are decreased due to 

reduced vehicle road loads (i.e., inertial acceleration, rolling resistance, grade)

– For constant performance, 20% mass-reduction ‡ ~12-16% CO2/mi decrease
Among the distinguishing underlying factors on relative vehicle weight are the use of advanced 

materials (e.g., high-strength steels, aluminum) and mass-optimized designs 

Use of Mass-Reduction Technology

• Today’s vehicles use different amounts of mass-reduction technology

– For a given size and functionality, some models are heavy (by over 40%)

– Models with more mass-reduction technology can by 20-25% lighter (for a given size)

– Some automakers use far more mass-reduction technology across all their models
Mass-Reduction: Automaker Plans

• Major efforts to reduce vehicle mass are underway

Company Quote, statement, or commitment

Ford

• From 2011 to 2020: “Full implementation of known technology... weight reduction of 250-750 lbs”

• “The use of advanced materials such as magnesium, aluminum and ultra high-strength boron stee

offers automakers structural strength at a reduced weight to help improve fuel economy and meet 

safety and durability requirements 

Toyota • 10-30% weight reduction for small to mid-size vehicles

Volkswagen • “Automotive light weight solutions are necessary more than ever to reduce CO2 emissions ”

• “Multi-Material Concepts promise cost effective light weight solutions ”

GM

• “We... are likely to use more lightweight materials in the future”

• “One trend is clear - vehicles will consist of a more balanced use of many materials in the future, 

incorporating more lightweight materials such as nanocomposites and aluminum and magnesium

Mazda • Reduce each model by 220 lb by 2015; another 220 lb by 2020

Nissan

• Average 15% weight reduction by 2015

• “We are... expanding the use of aluminum and other lightweight materials, and reducing vehicle 

weight by rationalizing vehicle body structure

BMW • “Lightweight construction is a core aspect for sustainable mobility improving both fuel consumpt

and CO2 emissions”

Renault • “To meet commitments on CO2 emission levels, it is important that we stabilize vehicle weight as 

from now, and then start bringing it down.”
Stahl, A., 2010. “2011 Porsche Cayenne breaks cover in Germany.”

http://www.insideline.com/porsche/cayenne/2011/2011-porsche-cayenne-breaks-cover-ingermany.html. January 8. Accessed April 7. 

Use of Mass-Reduction Technology

• One example: the 2011 Porsche Cayenne

– The model year 2011 offers a 10% weight reduction from mass-reduction technology

– 550-lb reduction (with 154 lb of added amenities) ‡ 396 lb net reduction

– And actually slightly larger size than 2010; also Porsche’s first hybrid offering

Aluminum hood

Aluminum chassis 

components

New door 

production process

Aluminum doors

High-strength steel 

throughout body

Aluminum tailgate

High-strength steel 

chassis components

Aluminum fenders

Lighter all-wheel-drive 

system design

Source:
Vehicle Mass and Body Mass 

• The vehicle body or “body-in-white”

– Core structure and frame of the vehicle; roughly one-quarter of vehicle mass

– Fundamental to the core structure and integrity of the vehicle

– Often the critical part of the vehicle that is designed in mass-reduction concepts

System Major components in system

Body-in-white

Passenger compartment frame, cross and side beams, roof 

structure, front-end structure, underbody floor structure, 

panels

Powertrain Engine, transmission, exhaust system, fuel tank

Chassis Chassis, suspension, tires, wheels, steering, brakes

Interior Seats, instrument panel, insulation, trim, airbags

Closures Front and rear doors, hood, lift gate

Miscellaneous Electrical, lighting, thermal, windows, glazing
Vehicle Body Mass Reduction

• Major reductions from production vehicles, prototypes, design concepts

– Many designs with 20%, 30%, 40%+ reduction of vehicle body mass
Vehicle Mass Reduction: Strategies

– Steel-intensive design

– 15-40% reduction

– Many OEMs, ThyssenKrupp, Porsche, 

Auto/Steel, EDAG, Ford, Lotus, VW

– Aluminum-intensive design

– 30-45% reduction

– Audi, GM, Honda, Jaguar, Ford

– Multi-material design

– 30-50% reduction

– VW/Superlight car, Lotus, DCX

– Carbon-intensive design

– 40-60% reduction

– Dodge, RMI

• Major reductions from different approaches
Vehicle Mass Reduction: Materials

– From 1995 to 2007

– Magnesium: +100%

– Aluminum: +22%

– Plastics/composites: +25%

– High-strength steels: +45%

– Lotus baseline to Low Development

– Magnesium: 3x 

– High-strength steels: 1.6x

– Lotus baseline to High Development

– Magnesium: 26x

– Aluminum: 2x

– Plastics/composites: +20%

• Material composition: a continuation of past trends
Overall Vehicle Mass Reduction

– Lotus (2010) designs use some similar techniques, materials of the PNGV (~2000) models

– Both show range of approaches with 20-33%+ vehicle mass reduction

– But now many new low-cost techniques are proven in existing vehicles

• Materials and designs can offer promising vehicle mass reduction

Lotus, 2010. An Assessment of Mass Reduction Opportunities for a 2017-2020 Model Year Vehicle Program. March.

Schexnaydor et al, 2001. Environmental Evaluation of New Generation Vehicles and Vehicle Components.

Sources

:

Lotus Engineering (2010) mass-reduction study Partnership for a New Generation Vehicles (PNGV) program 
Mass-Reduction: Costs

• Some of the mass-reduction projects also estimate costs

Automaker Findings related to vehicle costs of mass-reduction technology

Ford F150 “IMPACT”

•19% mass reduction at zero net cost

•25% mass reduction at $500 increase in variable vehicle cost

ThyssenKrupp 

“New Steel Body”

•24% body mass reduction at 2% manufacturing cost increase

IBIS aluminum •40%+ body mass reduction for $500-600 cost increase (aluminum body)

•17% vehicle mass reduction for $100-200 vehicle cost increase 

Volkswagen-led 

“Super Light Car”

•22% body mass reduction “multi-material, economic”at <5 €/kg 

•39% body mass reduction “multi-material, advanced”at <10 €/kg

Lotus

“Low Development”

•20% vehicle mass decrease causes 2% decrease in cost (~$300/vehicle)

Lotus

“High Development”

•33% vehicle mass decrease causes 3% increase in cost (~$500/vehicle)

– Near-term incremental approaches - up to 20% - have minimal costs

– More advanced technologies (~30% mass reduction) could have more

substantial vehicle manufacturing cost increases.
Mass-Reduction: Upstream CO2

• Some materials have larger upstream energy and CO2impacts

– The vast majority of vehicle’s CO2 emissions are 

due their use of energy during driving

– But manufacturing, end-of-life stages differ by material

– And more efficient vehicles put increased proportion 

of energy/CO2impacts upstream

– Materials, like aluminum and magnesium, are used 

on many mass-reduction designs and warrant 

further consideration of upstream impacts 

WorldAutoSteel, 2007. http://www.worldautosteel.org/Environment/Life-Cycle-Assessment/Automotive-Material.as

Source:
Mass-Reduction: Safety

• Issues of safety is commonly raised with mass-reduction

– From U.S. EPA and NHTSA:

“... the likely deleterious safety effects of the MYs 2012-2016 

standards may be much lower than originally estimated. They may 

be close to zero, or possibly beneficial if mass reduction is 

carefully undertaken in the future ”

– No known impacts from mass-reduced components 

(aluminum engine, carbon fiber roof, aluminum doors)

– Many of the above projects found no compromises.

– The recent studies (Lotus, Super Light Car, Future Steel 

Vehicle) continue to investigate structure, crashworthiness

– Many Five-Star safety rated vehicles are no heavier for a 

given size than others

– Half of them have lower mass than industry average

U.S. EPA and NHTSA. Final rule for MY2012-2016 CO2 and fuel economy standards.

NHTSA 5-star safety ratings (frontal, side driver, side rear), model year 2008 (www.safercar.gov)

Sources

:
Conclusions

– Mass-reduction technology is a core efficiency technology

– It has been, is being, and will continue to be deployed by automakers

– There is a variety of known approaches for mass-reduction

– High-strength steel, aluminum, multi-material designs will all be prominent

– Many off-the-shelf options for use of advanced materials, components

– Deploying best-in-class options for components throughout the vehicle

– Up to 20% mass reduction, minimal costs, near-term ~2015 availability

– Many emerging concepts are available

– New manufacturing techniques, greater use of advanced designs

– Up to ~30-35% mass reduction, additional costs, mid-term ~2020 availability

– Areas for further study

– Full manufacturer costs, crashworthiness, upstream CO2impacts, 

manufacturing phase-in, inclusion with electric-drive technologies. 
Vehicle Mass Reduction: Conclusions

– Lutsey, N., 2010. Review of technical literature and trends related to 

automobile mass-reduction technology. Institute of Transportation 

Studies, University of California, Davis. UCD-ITS-RR-10-10. 

http://pubs.its.ucdavis.edu/publication_detail.php?id=1390

• Acknowledgement

– Study done under contract for California Air Resources Board

• See publication for documentation
Mass-Reduction Technology 

(and what it is not)

• Vehicle mass-reduction technology is not “downsizing”

+ Mass-reduction technology: the redesign 

of vehicle models with advanced materials 

and designs for reduced mass (without 

compromise in vehicle space, utility)

– Downsizing: referred to generally 

as a shifts in the fleet toward 

smaller vehicles
Hybrid Technology: GHG Reduction

• Hybrid vehicle models commercialized in U.S.

– Span vehicles: compacts, sedans, crossovers, large SUVs, pickups

– Average 33% CO2/mi reduction, 50% mpg increase vs. similar non-hybrids

– Hybrids also put an upward pressures on vehicle mass (~9%)

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