i was averaging ~23mpg. i purchased the ultra-gauge and 2 of my gauges are instant mpg and avg mpg. if anybody has this you know what i mean - you really do change your driving habits. red lights, trips to the atm, etc. all effect you avg mpg. i sit at a stop and watch the avg mpg click down - seemingly very quickly. i'm a little lighter on the foot now and i've gotting my avg up to 25 but the car is too fun to be light all the time. stepping on it from a stop and you get ~3mpg on the instant gauge. i have calibrated my ultra-gauge for distance and fuel as per the instructions and my trip odo, mpg, and fuel level is dead on.