Well I have a 89 dodge colt. I Usually get 39-43 mpg on the highway. But this last week i got a tune up and I also replaced my thermostat and my timing belt. But all of a sudden my car is having a hard time getting anything above 28-30 mpg on highway. I haven't noticed any significant change in city driving. Wold anyone kow why this is????????

It's possible that the timing is a bit retarded. Have you noticed a decrease in performance? Were the correct plugs used? These cars seem to run best with Denso or NGK.

Well I fiest for the tuneup done. And then it was fine. I decided since I was going on a trip to change the timing belt. Because the guy who sold it to me told me that all these things were done when i baught the car. So to be safe i change dthe belt and it was a good idea. It was the original belt and it had 117,000 miles on it.

At first there was a loos of power. The the mechanic fied that. He said the timing was a bit off. And evething was fine. During me trip my car wouldne heat up. I figured that why i was getting bad gas milage. But after I changed the thermostat it was still the same.

I donno if i'm going paranoid here. But i started noticing yesterday and today that, when the sun is up and its worm its doing good on gas. But when it gets cold outside and gets cold then its doing bad on gas.

If this is true why can it be. Or may be i'm just over concerned... but the fact is still that it does bad on gas after me tuneup.

What temperature thermostat did you install?

195 degrees, car heats up really fast. Its great.

If the car is performing as it should and, noting that the correct stat has been installed and the timing has been verified, keep a record of the mileage over the next month and see the situation somehow is an anomaly and ameliorates itself.