Well, it seems each FD is different, but I've noticed no change in mileage since changing to the Pettit ECU.

 

not sure what I was getting with the stock ECU since I switched it out 2 months after I got my 7. W/ the M2 I got an average of 23-24 mpg when I drove from FL to WI. City mileage seems to be a little lower my guess is because of the changed fuel maps.

 

Power FC uses the fuel pretty efficiently I think that would be a wise choice... I didn't really notice too much difference.

 

It depends on the car, as each stock ECU has the same map, and works better on some engines than others due to small differences in construction. As a result, sometimes you'll get higher, sometimes lower sometimes the same mileage out your car.

The stock ECU as I understand it overfuels to keep it on the safer/reliable side, so by using a programmable ECU you can better tuned it for your individual motor, and get the best possbile MPG.

 

i get 12-14 mpg in town and 20-22 on the highway.

 

zooq, is that on the standard ECU? oh, and is you foot made of lead

 

With not much highway driving, I average around 13-14mpg no matter how hard or soft I drive the car.

If I add in more highway miles, then the average goes up, but normal city driving is aroun 13mpg no matter how I treat the car.

 

I get better mileage with my PFC then I did with my M2. The M2 was just programed to run rich.

 

During cruising all the aftermarket "chipped" ECUs should be the same. They only start adding fuel in closed loop mode, so at 0psi/3k rpms. Then, things go quickly downhill . Programmable ECUs can be tuned to get even better mileage than stock, which is pretty cool. Lots of people have reported 1-2mpg better with PFC base maps, not a surprise since even the stock ECU is tuned richer than need be.