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Automotive CO 2 Emissions Characterization by U.S. Light-Duty Vehicle Platform. John DeCicco, * Feng An, † Huiming Gong † Presentation at the TRB Annual Meeting Washington, DC – January 2005. * Environmental Defense † Energy and Transportation Technologies, LLC. Overview.
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Automotive CO2 Emissions Characterizationby U.S. Light-Duty Vehicle Platform John DeCicco,* Feng An,† Huiming Gong† Presentation at the TRB Annual Meeting Washington, DC – January 2005 *Environmental Defense †Energy and Transportation Technologies, LLC
Overview • Objectives (why look at platforms?) • What is a platform? • Methodology and data sources • Platforms in the U.S. auto market • CO2 Emissions Characterizations • Explore variability within and across platforms • Compare platform efficiency estimates • Conclusions
Objectives Why look at platforms? • Link CO2 emissions and related factors to the way production is organized. • Proliferation of nameplates and artificiality of the car-truck distinction makes traditional class-based analysis more difficult and less revealing. • Foundation for analyzing issues of part-scale production and staggered design change. • Provide a basis for assessing costs pertinent to production credits or similar incentives.
What is a Platform? • In general, a collection of manufacturing assets shared among different products. • Historically related to common chassis components and "hard points" for an assembly line. • Flexible manufacturing long since obviates need for fixed dimensions. • Platform ("architecture") now entails sharing of both "soft" and "hard" assets.
Platform Strategy as a Balancing Act Maximizing the market benefits of product differentiation Minimizing costs througheconomies of scale
Data and Methodology • EPA & NHTSA data for fuel economy, matched to trade (Ward's) platform data • Only up to 8,500 lb gvw, even though some platforms also include heavier models • Platforms are not always "well defined" • MY2002 sales, CY2002 platform production • early MY2003 models not counted in sales • Nominal, direct CO2 emissions based on 8.8 kg/gal, 15% fuel economy shortfall • Diesel and AFV use assumed negligible (diesel LDV share was only 0.1% in MY2002; estimated FFV credits were backed out)
Top Platforms Ranked by U.S. Sales Next 5: Ford Explorer, Honda Accord, Chevy Trailblazer, Chrysler Voyager, Chevy Malibu
Variability within a Platform • Factors: # of engines, # of body styles, weight • Examples • GMT800 (Silverado, etc.)7 models, 5 engines, 3 body stylesvariations: 33% in disp, 26% in wt, 23% in CO2 • Dodge Dakota/Durango2 models, 4 engine, 2 body stylesvariations: 75% in disp, 31% in wt, 45% in CO2 • Honda Odyssey / Acura MDX2 models, 1 engine, 1 body stylevariations: (0) in disp, 5% in wt, 6% in CO2 Variation ≡ (Max-Min)/Mean [sales-weighted]
Typical Variations within a Platform • Weight, in general, varies least: median 17% • Greatest variation (26%-35%) in pickup platforms, which include body-on-frame SUVs • Engine displacement median variation: 26% • Greatest for compact pickups, with I4 - V8 options • CO2 emissions rate median variation: 20% • Outlier is VW Jetta, with diesel: 67% variation • For others, compact pickups show 45% variation N.B. Drive type was not examined, but other analysis indicates typical 10%-15% CO2 impact for 4- vs. 2-WD.
Variability Across Platforms • Comparing platform averages (but remember the significant within-platform variability) • Examined: • Power, specific power (HP/L) • Ton-MPG • Reciprocal of mass-normalized fuel consumption • Isolates non-mass-related aspects of efficiency • A good (but not perfect) index of powertrain efficiency
Ton-MPG Indeces for Selected Platforms (identified here by representative models)
Ton-MPG vs. average platform weight No correlation to weight (r = -0.04) Ton-MPGfor trucks only 5% lower than cars on average Some, but not all, large variations reflect platform age ("dated"-ness)
Conclusions • Platform-level data enable analysis linked to how the industry manages production • Highest volume platforms contribute, by a modest margin, disproportionately to CO2 • Top 30 ⇛ 69% of sales, 72% of CO2 (MY2002) • Variability within and across platforms can reflect some opportunities for CO2 reduction • Newer platforms generally more "efficient" • Provides a baseline and foundation for several types of future analyses