What shape is your timing belt in?
Did you change the fuel filter?
Did you change the air filter?
Are you running the air conditioner?
Are you driving harder?
Do the tires have proper air pressure?

 

The fuel filter can not be changed it is built into the fuel pump. Air filter is good recently changed. Always run the AC and fuel mileage did not suffer but .5-1.0 MPG, not driving any harder, tires inflated properly.

I commute about 70 miles one way highway each day, my average MPG was around 28 now its around 24-25. When I used to do 55 MPH, I could get 36 MPG now I can only get 31 MPG doing the same thing.My average is down 3-5 MPG. Since I've gotten the car I've talked to other owners and they say they have gotten better fuel mileage then me running around town and doing highway, driving at 70-75, just like me. I know 02 sensors will trip a code, but I'm wondering if maybe they are bad but not bad enough to set a code off?

My next step was to check the PCV valve, the operators manual has nothing in there in regards to the PCV valve. I also use Mobil 1 5W20 and change the oil filter every 7,500 miles, change the oil every 14-15k miles. Even BEFORE I Switched and was using the dealer oil/filter the fuel mileage was starting to drop. It's baffling. No extra weight in the car either. I've had the car 1.5 years now. I'm spending $65.00 extra in fuel due to the drop.

Can you advise on the PCV valve location? I searched archives I know I read somewhere and the post mentioned the dealer could not find a PCV valve.-Byron

 

 

The PCV valve location is behind the throttle body. Remove throttle body to access the valve. The valve screws into the engine block on one side of the valve and connected to a hose on the other. Remove the valve, shake the valve, if you hear a noise then it's good. You can always clean the valve with carb cleaner if it needs cleaning.