[gcb]

Previous diesels were awful because of the stuff we had in the diesel itself. The engines are still the same, mostly. any year car you get that still have good compression will give you a clean burn (if it's too lean, you get too much nitrogen oxide, to rich you get carbon and shoot).

if you want to go the extra mile you can either buy the hamburguer smelling vegetable conversion kits (too much hassle to refil imho) or you can spend extra and put a modern catalytic system in the old car and be done with it.

a 2000 VW, Audi, mbez will do wonders and cost from 6 to 12k.