this is thing I'm thinking about for few years. why standard passenger car diesel engines are so limited in engine capacities range? if we take petrol engines, there are anything from 1.0 liter to 3.0l Inline 4 cylinders, 2.0-4.0l 6 cylinders (or even bigger in USA), 4-7l V8 etc. but take diesels. I4 are only 1.4l-2.5l, 6 cylinders? 2.7l-3.0 liter. V8 3.6-4.2 ? most diesel engines have cylinders 0.5 liter big, or somewhere really close to that. there are few bigger engines in offroaders (up to 3.2l 4cylinder for mitsubishi, and I think 4.2 6cylinder for old toyota off road) but that are truck engines why is that? why is easier for BMW to have 2 or 3 turbochargers on 3.0 I6, than producing 3.5 or 4.0l I6 ? only thing I can think off is bad NVH for bigger diesels. but can that be? big cylinders should have lesser thermal losses and better efficiency. and that is really important nowdays. any ideas?