Hey Everyone,
Bought my tC in Feb '05 and I was getting pretty good mileage (~26-29, 24 on bad weeks). That was when I was in OC (think california). Now I'm in SD and though I was getting relatively good mileage in the beginning (24-26), my last tank came in at ~18 miles per gallon. Can anyone think of why this would drop so much? I didn't drive any differently between my last tank, I checked all my tires (~33/30) and I didn't change my routes. I don't even use the AC... My last oil change was about ~3500 miles ago, and my car is at 18.5k... I even got gas at the same station as I always do. I'm going to try some fuel injector cleaner, but seriously, a 6 mpg drop? I'm thinking I should take it in to the dealer, but call me paranoid, ever since I brought my car into the SD dealer down here, I feel like my car has been performing a lot worse...

 

Sounds like you're running poor quality E10 (ethanol laden) gasoline.

 

I use ONLY Ethanol and get around 26.5 mpg.

 

It could be that the last time you filled up, the gas pump cut off early and you didn't really fill the tank. I wouldn't worry unless you're next tank (or 2) are off as well.

 

I'll check my mileage on this tank. One thing I forgot to mention is that the tank I filled up on prior to the 18 mpg one came in at ~21 ... it seems to have been steadily decreasing as of late. I used to get anywhere between 24 and 26. But i'll let everyone know when i get my next tank (which will probably be a bit skewed though as I put in fuel injector cleaner and will be driving long distances this weekend for Father's day).

 

i didnt know we can use ethanol in out cars.