There aren't any recent diesel-specific threads, and I've got diesels on my brain right now. What I don't want in here, is "diesels are a stupid idea". If you think that's the case, please just move along. What I would like to discuss is: Available diesels in N.A. (or mail order from china) that might prove suitable in a homebuilt aircraft. Say from 50 to 200HP range. Mazda has a recent one - the "skyactiv-d" that is all aluminum, extremely light weight (can't find numbers though) and should be available in junkyards cheaply within the next few years. Reliability is still an unknown, and so is figuring out how to make the computer work outside of a car, or using an aftermarket computer on it at all. The Chevrolet cobalt also came with an all aluminum diesel recently - though I can't find much about it. I've looked into the recent chrysler/mercedes V6 diesels and think they're too heavy to bother with, it really looks like straight-4's are the only automotive option with any sort of reasonable weight. Anyone know of any air cooled options? Or other motors, please link to them/discuss their merits and potential issues in here.