With several threads on how bad mileage can be at high speeds I wanted to do a true test. Recently I felt my Prius could get 42-44mpg at 85-90mph. I filled up with 4 people and the trunk fully loaded and hit Alligator allley from Miami. I stayed at a steady 85-90mph as you can see my average speed was 83mph. I was doing this speed from 1 miles after the gas station. So fully loaded at 90mph was 35mpg. No air conditioner and no heat.
What did you expect? You should try this with a similar 1.6L midsized sedan like a Corolla and you would be still VERY happy that you have a Prius.
I'm not complaining. I realize this is great mileage all things considered. My other cars get 17mpg at those speeds.
