Fuel Economy Policy Could Bring More Supersized Pickups

The notion of making vehicles that are not so large, or not so powerful, as a legitimate approach to reducing fuel consumption is unpopular these days. Near-unanimity on this point led to the shift to ‘attribute-based’ CAFE standards mandated by the Energy Independence and Security Act of 2007. And in fact that shift does seem to have helped to push fuel economy increases over the top legislatively, setting the stage for two impressive back-to-back rounds of standards (or proposed standards) that together are projected to double light-duty vehicles’ fuel economy by 2025, relative to 2005 levels.

So let’s grant for the sake of argument that a viable policy approach to promoting fuel economy gains in the U.S. today can’t promote smaller vehicles. More precisely, the slope of the curve plotting fuel economy targets against vehicle footprint must be steep enough so as not to drive manufacturers to meet their targets by reducing vehicle size.

Unfortunately, auto companies drove that idea hard enough to bring about standards that push vehicles in the other direction. Recent University of Michigan research applied a manufacturer competition model to determine the influence of size-based standards on product decisions and found that the standards put in place for model years 2012 to 2016 would likely increase vehicle size, diminishing the fuel savings of the rule by 5 to 15 percent.

The fuel economy standards proposed for model years 2017 to 2025, while quite strong on the whole, would aggravate this problem by setting an unaccountably steep light truck curve. That means the effort to avoid standards that promote the downsizing of vehicles could instead end in substantial upsizing of trucks, with the added fuel consumption and traffic safety erosion that would likely accompany such a trend. That weakness in the proposed rule should be remedied, either directly or by setting a minimum oil savings requirement for the program.

Therese Langer is Transportation Program Director of the American Council for an Energy-Efficient Economy, www.ACEEE.org