350 mile trip.. and I got 28 mpg averaging 90mph.if it won't kill you, drive the speed limit. I'm one of those drivers that goes 5 over all the time, but just for fun i compared fuel mileage. at 70, i got 28 mpg, at 65, I got 32.
just stick it in the tube near the TB.... dont bother extending the wire. Its easier.