The motive for this study is a question raised by Folksam on how well the criteria currently used, which have a focus on CO2 emissions, reflect the total environmental impact of exhaust emissions. One of the questions is whether diesel cars, being more fuel efficient, are preferable to gasoline cars given the differences in for example particle and NO2 emissions. Since the latter emissions are known to have health impacts, if they are to be accounted for there is also the question of how to compare these health impacts of the cars with their safety aspects.