The best mpg I have got is 34. This was because I was trying hard to get the best mpg the car can give. To get this kind of mileage, I had to drive very conservatively. Mainly driving with minimum acceleration and braking. If any acceleration reuqired, accerating very slowly. Also, I let go off the gas whenever I could and tried to maintain a constant speed. The fastest I went during this experiment was 60 mph.
Under normal driving condition I get an average of about 26-27 mpg.