Body Roll

http://www.roadandtrack.com/article....rticle_id=3737

Please help me understand what is meant by
" and establish different standards for different types of cars." ?
Does it mean that low displacement cars will be forced to achive 30 mpg
average
while Ferrari trucksters could get away with 14?
Or does it mean that 27.6 mpg would have to be achieved by the
trucksters vs. current 21?

Not an abstract question considering an already shitty gear ratios and
throttle response on my 2005 Impreza. (Thank you Subaru, thank you very
much).