After having a new exahust upgrade I noticed my estimated gas readings stay around 25.2, whereas the estimated tank average would vary. I also noticed estimated miles left for the tank go from 400 a tank to even worse. Anyone experience this problem? Did it have to do something with the O2 sensors?

Thought I'd finally ask after reading several postings that the estimated mpg readings are not a good way to determine actual gas tank averages but still....I had bald a tank left and it says I had 150 miles left...that seemed way off....especially when it says 25.3 avg mpg?

 

could it just be a case of your foot becoming heavier due to the louder music coming out the back?

What was your readings before? Now I'm no scientist, but if it was a simple bolt on, you should actually be seeing improved mileage since airflow is improved, no?

 

I installed my exhaust last week and I am wondering the same thing too...occasionally I slam on the gas but I'm stuck between 19.5-22.0, it was higher before.

 

Its probably your foot pushing down on the pedal more often lol. Ive had about 3-4 different exhaust setups and this has never happened to me.

 

My MPG stayed the same and I have F-Sport Exhaust. Only time it changed was when I pushed down on the pedal more.

 

My MPG went down too after an M2 install by about 2-3mpg. Definitely not driving any more aggressive either.

 

Not much of a difference for me. I was averaging 18.2 when I had my F-Sport Exhaust. I took it off and put the stock exhaust back and now I'm averaging 18.6