My mpg hasn't been what i thought it would be. I've made the same 215 mile trip a few times. Each time I get 33-35 mpg. Is there a reason y i can't get up to 37 mpg or more. I drive at about 72 to 80 mph. Most of the time i have more than one person in the car but the last time it was just me and I got a little under 35 mpg.