actually it does....... but i am not one to explain it, might ask onepoint8 or cincy

i think it has to do with how the tunning changes your map settings.... blah i dunno

 

I'm guessing that the stock fuel map is slightly rich to keep the engine safe and as reliable as possible. When you get it chipped, it leans it out slightly when you're out of boost, so if you stay out of boost you use less gas.

When you're in boost you'll use much more though.


Right? maybe? no?


edit-
Threadstarter... Just go see if you can hit 135mph, stock our cars are limited to 127 or 130, so if you can get over than then you're chipped

 

When making more power it takes less time to get up to speed and then you let off the throttle and hold that speed, so you are not boosting and using very little fuel. Also chips tend to run slightly leaner at part throttle and out of boost, while Audi sends them out running slightly on the richer side to play it safe.