Car bumper standards are not demanding enough to prevent expensive crash repair costs even in low-speed accidents, according to the Insurance Institute for Highway Safety. This "bumper mismatch" of size and position allows the bumper from a larger car, truck or SUV to ride over the bumper of a compact car and damage expensive car parts such as radiators and headlights.

The Insurance Institute of Highway Safety concludes that the lowering of the standard car bumper test speed from 5-mph to 2.5-mph by the NHTSA is causing car crash repair costs to exceed any economic benefit that lighter and cheaper bumpers would afford from their reduced cost and increased fuel savings. The NHTSA asserts that by reducing bumper size and weight, the cost of vehicles would be reduced without increasing the frequency of accidents, fatalities or injuries.

With the sizes of cars decreasing while their mechanical complexity increases, the IIHS feels that car bumper standards should be modified to reflect to accommodate for the cost of crash repairs. Accordingly, it is conducting its own car bumper tests at 3-mph and 6-mph which show the vulnerability in models such as the Toyota Prius and Infiniti G37. Models such as the Scion xB and Ford Focus survived the tests with less expensive repairs.