No, not biodiesel. My brother has a '91 diesel golf that he is selling. I was thinking of buying it, but I much prefer the jetta that I have, except that it's a gasser. Would it be more expensive to sell my car and buy a diesel, or is it possible to remove the gas motor and install a diesel? Seeing as how the older VWs are all made like lego in that you can take out parts and put in new ones without more than thinking about it. Other than the motor and fuse box, what else is there to consider?