There is a straight-4 cylinder Cummins B diesel engine that comes in 3.3L and 3.9L sizes.

http://en.wikipedia.org/wiki/Cummin...

Wikipedia says the B4.5 is used in agricultural vehicles, while the B6.7 is used in passenger engines. Anyone heard of the B4.5 used in passenger cars or trucks? Would it run on wvo? Is there a 4 cylinder Cummins that is already in passenger vehicles?

I know the Cummins B, especially, is one of the better diesel engines for wvo, but it would be cool if there were one that got really good mpg! Thanks for any links or comments!!