^^ thats a huge variance. i used to get 300 easily to a full tank on my 06.

 

I've had 2 my06s the first one would consistently get around 300 mi/tank
The new one (lower mileage) gets around 220-250... I am running a test pipe on the new car, and an 02 sensor that came (slightly used) from the previous owner of the test pipe. I may swap em with my old 02 sensor and try to see if that solves my issue, thanks for the tip!

 

Most of my driving is city so my variance is even larger. I'll get 18-19 in the city and have made it to 33 on road trips.

 

well in the end aslong as that mileage quantifies smiles im all for it.

 

I don't see how the rear o2 could affect MPG since all it does is to monitor the cat...