According to researchers, proposed U.S. fuel economy standards are motivating automakers to build bigger vehicles that are allowed to meet lower targets.
The University of Michigan study discovered that the CAFE formula for setting mile-per-gallon targets, which are averages for all of a manufacturer’s vehicle models, is a loophole which gives incentives to automakers to build larger vehicles.
“This study illustrates that there may be a substantial financial incentive to produce larger vehicles, and that it can undermine the goals of the policy,” Kate Whitefoot, who conducted the study said in a University of Michigan release Thursday.
Each automaker must meet a standard each year determined by the literal footprints of the vehicles it makes, determined by track width times wheelbase. This regulation allows automakers to lower their average fuel economy targets.
The footprint-based formula, created in 2006, was meant to prevent an influx of smaller vehicles, as critics worried the previous one-size-fits-all standard unfairly rewarded production of smaller, lighter vehicles that could put the U.S. industry at a disadvantage and drivers at greater risk.
The study revealed that a sales-weighted average vehicle size in 2014 could increase by 1 to 16 square feet, undermining CAFE fuel economy improvements between 1 and 4 mpg.