I own a 2005 Chevy Cobalt and I've had it since it was brand new. It has the 2.2 liter engine and about 23,000 miles on it. I have been noticing that my fuel economy has beengradually going down in the past few months. According to the digital fuel economy gauge it's gone from over 29 mpg to a little over 25 mpg and it is still going down. Are these gauges accurate? I try to keep my tires at the proper air pressure, change my oil every 3k, do all my maintenance,etc. I noticed it started going down after I had some work done to it(bad wheel bearing and brake pulsation). With the low mileage on it I doubt it needs a tune up. I was wondering ifa clogged air filter or fuel filter may be causing this problem although I checked my air filter and it looks fine. Any input on this problem?

 

With 23,000 miles on it, a tune up couldn't hurt. When was the last time you had an oil change?

 

What the "gauge" shows is the average fuel economy. The more you drive it (especially city driving) the more it will go down.

To get a better idea of the mileage you're getting at any one particular time, just re-set the gauge. To do this press and hold the reset button while the gauge is showing.

Hope this helps!