Diesel has had a hard time catching on in the world. It’s not that it isn’t fantastically efficient, or doesn’t offer stellar performance potential. Ask Gale Banks or Wayne Gerdes (both world record holders in top speed and fuel economy) about diesel’s performance potential. But the simple fact is that frugal isn’t sexy, and sex sells cars. Cars sell on big, loud and stupid awesome as much as anything else — and BMW at least seems to be slowly adapting to that reality.