I've been wondering for the past few days, is there anyone that knows of a company that makes an MPG gauge. I've seen older cars have it, old 88' caddys, new 09' fits, and everything in between. but those are all built in from factory, and I've been wondering if they make after market ones. so if anyone knows of something like this for pretty cheap (under $100) and that works with obd0 would be great! thanks!