3.4 mpg on a EVO 8 FQ400?

[Cplus]

yes maybe but for the most part all major other things being equal they would be. IE assume same fuel, A/F ratio, etc.

true.

But I would very much doubt a healthy high compression V8 (for example, I know the GT40 is not) would run the same AF as a low compression 4 cylinder lag monster at full noise.

[The Pupat]

Yeah, you've also got a whole heap of other bits and piece like the VE caused by a low compression and probaly using the fuel to cool the motor.