Originally Posted by Nic
Sorry guys, but you're wrong. Speed is a product of gearing and engine rpm. No matter what other factors are involved, the vehicle cannot go different speeds at the same rpm in the same gear. That would require the vehicle to somehow miraculously defy the laws of physics, which, to the best of my knowledge, cannot be done. Whether a car is capable of achieving said speed on the street vs. on the dyno is a different debate, which we'll save for when the time is right.
All this is true...unless we move from manual transmissions to automatic transmissions. When doing this one would also have to take into account any converter slippage that may occur under a load which could cause rpm and mph to be off when comparing street and dynojet numbers.