content: Know this - if they "fix" your VW because of this issue, you will lose power and efficiency.  If I were the owner of a VW diesel I would be very torn about this issue, because I would be reluctant to increase my fuel mileage and decrease the power of my car.  Diesels that meet the emissions requirements do not run dirtier, but the VW is 40x dirtier because of the "cheat." The same emission limits apply to all vehicles regardless of the fuel they use. That is, vehicles fueled by gasoline, diesel, or alternative fuels all must meet the same standards. Since light-duty emission standards are expressed in grams of pollutants per mile, vehicles with large engines (such light trucks or SUVs) have to use more advanced emission control technologies than vehicles with smaller engines in order to meet the standards.