Emissions equipment, it keeps pollution down, but seems to keep MPG's down too, so, if you removed the regulations, and let motors run like they could, would they could get way better mileage? So why the tradeoff? If you just use less gas to go further, isn't that better than burning more of it slightly cleaner?

 

Modern day emissions do not hurt them that much. Its the airbags, TCS, extra bracing, a/c, sound deadening, etc... in other words, weight that is killing the mpg. How many cars on the road weight in under 2k pounds now?

 

The only emissions stuff hurting performance is the catalytic converters, and those only a little with a slight exhaust restriction. Everything before the exhaust pipe that makes the car run cleaner, also makes the car run better. The more efficiently gas burns, the less you need to burn to get the engine going. For sane people without lead shoes, that is.



Economy = cleaner emissions. Double win. Then you throw on 40lbs of converters.