Just looked under the hood today and noticed that my coolant is really low. There are 3 marking on tank thing. Full, Hot, and Add. Well my blazer is under add so i'm going to fill that up tomorrow. Could this be some answer to my prayers?

 

Low coolant like that, not likely. Mine was like that, but I took the opportunity to flush and fill mine (80k miles). I consistantly get 19's with a 60/40 highway/city split, if its an interstate trip on relatively flat terrain, I'm hitting 23+.

Make sure your tires are inflated to the specs on the doors. I run 32psi on the stock tires (before I checked, I was at 26 :O ) That should help a little. Your driving habits seem to be like mine (mild/moderate acceleration, speed limits, etc)

ninja-edit: I keep mine <2k rpm which is around 65mph for highway. Yeah, I might drive like an old-man, but the difference in 65-75 isnt worth it for time savings or fuel eco (IMHO). 2k rpm is my sweet-spot for 19-20 mixed mpg.

 

I guess im just going to have to wait till I go to college next year for automotive.. maybe one of my teachers will help me. oh yeah I did check my tire pressure before my last trip. they are fill 32 psi of nitrogen