Basically I think what they will do is try to make the tests more like an everyday drive instead of putting a car in a warehouse and driving it on rollers till it runs out of gas to figure the MPG out. Most of the EPA tests right now don't use considerations such as drag with windows or a drag coefficient at all or the use of A/C doesn't effect the MPG in an EPA test. I haven't heard anything specifically but I'm assuming they will start putting these factors into effect when rating new vehicles. and Cryptic yes this means cars will be rated with less MPG but also we all know it's not the car it's how you drive it that determines MPG.