Originally Posted by
LongFellow
You're saturn explination works wonders when people are running stock tire sizes, but in most cases no one is. Going to a 4.36 can net you improved gas milage.
Comparing the amount of gas used between my car (4.08 & 255-0-17) and epsteins car (4.36 & 245-40-17) in july on our 2000+ mile deals gap trip we always put the same amount of gas in out cars. I checked how much gas all our cars where using at the time and we used up about the same amount every time.
This can't be a serious post.
The saturn explanation is independent of tire size. You're not understanding BSFC.
Comparing one car to another does not make sense. More than likely, the two cars do not have identical tuning/modifications/driving.