[Lippyp]

You need to get an Isuzu 2.8 turbo diesel as found in UK MK1 Troopers and Vauxhall Fronteras (the frontera one is slightly more powerful with bigger injectors and an intercooler). I had an old Trooper and the engines are great, well capable of 300K miles if given regular oilchanges, they're no slouch either especially in intercooled form. They'd certainly be able of hauling an s10 around in a sprightly fashion and I was getting around 30mpg from mine. The later 3.1's went from direct injection to indirect and are quieter and more powerful but suck more diesel, both can be run on bio diesel or even a mix of diesel and straight waste veg oil.

This is the shape I mean (my old trooper working for its living)



The 3.1's were found in the later shape ones like my second one.