SUV. DH and I both drive Chevy Blazers.
We both got some kind of valve thing replaced - inline fuel valve? Does that sound right? Anyway, we're now getting about 24-25mpg on the highway, which is 3-4mpg more than before. I nearly passed out when I made my first trip to work after getting that thing replaced. I looked at the fuel meter and did a little happy dance. Sooooo worth it. I think it was about $50. or something - really reasonable.