[Katmandu]

Originally Posted by Formula413

As has already been said, a low restriction exhaust will really only provide benefit at high RPMs, which is basically irrelevant to FE. A simple explanation would be that under light loads the engine does not have to push very much exhaust gas out the exhaust, so whatever restriction exists in the exhaust is likely not hurting efficiency, while under heavy throttle at high RPMs there is much more exhaust gas being produced, and a low restriction exhaust means the engine will not have to work as hard to push all this exhaust gas out.

That is EXACTLY right on the money.