Possible Problem?
 

When I got my car, it was used. 16k miles on it. It could hit 26mpg if I tried carefully to get that. And it was fast, but I was used to driving a comparatively slower car, the Cobalt SS. So I didn't know if the car was at its peak potential or not. Anyway, I was traveling from Houston to Dallas and back to Houston today, and the best mpg's I saw was 23mpg. And that was hard to achieve. Also, don't judge me, but me and a 2008 350Z did a small pull from like 10mph to 50mph and we were dead even.... That's when I knew something was wrong haha. Does anyone have any insight? I've heard people being able to achieve 30mpg on these forums and I have problems at 23-25mpg. Thank you.

While driving on the highway reset your mpg calculator. If you can't get at least 28 mpg then something may be wrong. Easy things to check are tire pressure, air filters, and proper tire wear.

Can't get 28. All of the above items are fine.

jay
 

every day driving I only average 20.5 mpg

I'd kill for that. I average 15. :(

Come to think of it, it MIGHT be a lifter/rocker arm problem... But I doubt it. In my Cobalt I managed to snap 2 rocker arms and was running on 3 1/2 cylinders for several months. I knew something was wrong and that car was ticking and would flash a CEL above 5000rpms. But below 5k rpms is was fine. I had a small loss in gas mileage as well. What I'm getting at is that my engine makes a small ticking noise and I can't tell whether its normal or not.

When my Cobalt had the ticking noise, car experts of 30+ years told me it was normal and I knew it wasn't. When I popped the valve cover off and saw metal pieces sitting there, I knew I was right.

Any other possible suggestions? I think I'm just going to get a good oil change but Seafoam it right before I do.