How's that 3- treating you Coors, I know I had a ton of fun 3-, just wait till you get full fueling and really unleash the K04's.

 

Ok, well it seems like my turbos are operating in the correct range for being bone stock. Thats a good start, now my question is, "Why is my mpg so terrible?"

I bought the car 2 months ago and started updating the services. I have changed the DVs, Air Filter, Fuel Filter, changed synthetic oil (0w-30) and pressure tested the intake system. I started out getting about 15 mpg on the first couple tanks then after changing the fuel filter it jumped up to 21 mpg. (Here is a list of mpg for the last 5 tanks 14.8__18.1__19.6__21.1__15.2) Now with nothing changed on the vehicle, it has dropped back down to around 15. I am getting no error codes and havent really noticed a loss in power.

Any suggestions to what the cause for loss of fuel mileage might be? The only thing left to check or change is the spark plugs. Could bad plugs still give me good performance with bad mileage?