I have a 93 extended cab 4x4 with a 22re. I have never gotten good gas milage compared to other trucks like mine, but it seems to be getting worse and worse. I have stock rims, tires, gears, suspension, cam, everything really and I have been getting about 19mpg doing mostly highway driving at 65mph. Could my timing be far enough off to do that to me, and it still run smooth, and have decent power? I just put in new denso plugs, new wires cap and rotor less than a year ago, adjusted the valves about a year ago. I have been driving my truck like an old lady since I got it because my truck is my baby and if I want to go fast I have a crappy ass trans am for that. But now my truck is catching up to the trans am in fuel consumption. I have been doing a lot of head scratching lately because I just cant figure out what it's deal is. Any suggestions?

did you replace the air filter?

maybe time to replace the oxygen sensor too... been alot of info on O2 sensors here lately... if you look at the list of posts you'll see .. folks are suggesting that the best is a Denso or NGK like the originals for OEM fit and function and recommend going here for purchase
http://www.sparkplugs.com/

Yeah I replaced the air filter about five thousand miles ago and it is still clean. The only thing I have not gotten is an o2 sensor, I guess that will be next, thanks for the link.

You might also want to check your EGR. I have heard that as they start to get clogged, you get crappy gas mileage. On LCEngineering they sell a block off kit so you can take that off. I think I have the same problem with my truck.