with my 2600 pound E30 318 with TMS chip i get 25-MPG dricing freeway and moutain roads. Highway i get 40mpg around 80mph.
also the M42/44(4 cylinder) is an inline 4. V4 would be a street bike.
4.5 sounds good.
as for the mileage...its not that bad. My car has 140k and it can still reliably do 1000mile trips no problem.
We all get the urge...Saturday early morning...nothing to do till noon...
The aural sensations of 1st gear WOT
**CGM **(Certified Garage Mechanic)