What do you base that on?
"A National Research Council report found that the standards implemented in the 1970s and 1980s resulted in an additional 1,300 to 2,600 traffic fatalities in 1993. A Harvard Center for Risk Analysis study found that CAFE standards led to 2,200 to 3,900 additional fatalities to motorists per year. The Insurance Institute for Highway Safety's 2007 data show a correlation of about 250-500 fatalities per year per MPG."
Cars being made safer by better engineering does not excuse the reasoning behind CAFE standards. There is no need for CAFE standards and there are clearly measurable costs in human life.