Gas mileage

[reattaone]

I always got 17.5 to 18.5 miles per gallon. For the last few tank fulls I am only getting 13.5 to 14. What should I be checking????

[Guest Reatta1]

First thing I'd do is replace the O2 sensor.

[padgett]

Temperature gauge. If never gets over 146F. it never goes into closed loop. (Always check the easy stuff first)

[Guest joereatta]

It has been cold in Pennsy. Do you do a warmup in the am with a lot of idling? Regardless, I think Padgett nailed it with the longer time spent in the gas enrichened cycle.

[Guest imported_barra]

Have you checked your tire pressure? It has been cold and lower pressure is a by product. Also, have you been filling up at the same gas station? It could be the type of fill-up you're getting. At what point do you stop filling the tank? I could coax another gallon into the tank after a second automatic shutoff. The computer read out would show a higher miles per gallon than the actual amount I put in my tank. Just a thought.

[manikmekanik]

Check the "leadfoot" , and traffic time. In winter everything takes longer - warmup, signals, snow, etc.

We generally get 24+ MPG from our Reatta, Regal, and Riviera, all with same drivetrains, and 28-33 MPG on long hyway trips. Last trip for Black Beauty wasthe jaunt to Rochester, MN for the BCA Nats, AVG 91MPH @28 MPG, 4 hour trip, mid-summer temps of 100+

Look thru diagnostics, you may need a MAP, or TPS.