With the Supreme Court due to hear arguments today on a landmark case covering the authority of the EPA to regulate greenhouse gas emissions as pollutants, the San Francisco Chronicle yesterday addressed the question of whether limits on tailpipe CO2 emissions would spell the end of large SUVs, at least in California. While I agree with their assessment that technology can deliver at least the 30% reduction in fuel consumption implied by the emissions limits, they omitted a crucial factor in this equation: consumer expectations. Instead of heralding the end of the SUV, CO2 limits on cars would probably spell the end of large SUVs capable of delivering the car-like performance that has been a key factor in their success.
The case in question hinges on legal interpretations of existing anti-pollution legislation, over whether CO2 and other greenhouse gases constitute pollution that the EPA should regulate, and on the standing of the states to bring suit in this matter. Court-watchers seem to think it will be a close call. If the court finds for the states, the consequences could be far-reaching. It would certainly affect the kind of cars we will drive in the future, and it could even expose the basic process of combustion to product-defect suits. (I can just picture the caveman from Geico's current ads in the docket, defending whether he knew, when he invented fire, that it could harm the planet.)
With regard to the implications for cars in general, and SUVs in particular, the low-cost efficiency technologies cited by the Chronicle have already been deployed, including better fuel injection, and more advanced engines and transmissions. Although all of these have scope for further development, most of the improvements in these areas so far have been employed in the service of better performance, delivering better 0-60 acceleration and passing power, rather than increased fuel economy. As a result, consumers have been able to purchase 6,000 lb. vehicles that drive more or less like sports sedans. That reflects an expensive and sometimes hazardous consumer expectation that moving up to much larger, heavier vehicles entails minimal trade-offs. It ought to be perfectly possible to produce attractive, practical SUVs that deliver substantial fuel savings at a modest increase in sticker price, without resorting to expensive hybridization. What must give, however, is either weight--and thus size--or acceleration.
If consumers were willing to accept 0-60 times over 10 seconds, there's no reason they couldn't buy Tahoes or Expeditions that conform to a future greenhouse gas emissions limit. They just wouldn't be as nimble or fun. That might even reduce the temptation to drive these vehicles beyond the typical driver's ability to react safely to an unexpected hazard or bend in the road, in the process easing the threat that SUVs pose to smaller cars. I'm sure Detroit's design departments will be watching the Supreme Court proceedings closely.