Re: Average Gas Mileage
My roadster window sticker says 17/25. I drive it rather lightly, in that I generally shift around 2500-3000. I rarely do all city driving and my mixed is in the low 20s. I calculate (manually) 27-29 mpg on the highway at 70-80, and that has been consistent since I bought the car. 200 miles per tank is terrible and something is wrong -- I see close to 400 on the highway. Certainly check tires, then pull codes, check air filter. You did not mention mileage but it's possible 12 new plugs will help. Make sure you're running 0W-40 full syn and not 10W-30, although that should not make that large a difference.