The tire pressure was 2 psi off from recommended, and I have an automatic transmission. My friend drives very similar roads, and has the same transmission. These roads are on flat agricultural areas with occasional small hills. All two lane highway. Traffic isn't too heavy, and there are a couple of small towns we have to slow down in without a stop light. I would assume that my scenario is one of the best mpg situations out there. My old 94 escort manual would get 41 in those conditions