It is a pig in town, 17-19 mpg
Amazing in freeway, 26-28 mpg @ 60-60 mph, at which speed i go to/back from work.
It's OK on highway, 24-26 mpg, depend on speed (70-80 mph). If I drive more than 80 mph, it will get down to 23-24, which is not shaby.
I always inflate my tire to 90% of maximum (36 psi @ 40 psi maxium, and was 40 psi@44 psi max before when had Goodyear tires). I add regular gas (87), never used 89, or 93.