So I recently had a radiaiot in my 89 toyota pickup blow. I fixed it and put in a new thermostat. Before I could go into the mountains and bomb around and still not loose a 1/4 of a tank. Now I drove on the highway did a quick around a farmers road to check out the terrain for snow and came back and went from a 1/2 a tank to a 1/4 of a tank without even going 10 miles. I know my TPS is going out and I need a new one and I just put 31's on my truck but that shouldn't be causing this much of an issues. It's a 22-RE 4 speed auto, ran a computer chck and only came up with the TPS but it shouldn't have droped my gas mileage that bad. I didn't have my truck in 2nd or 1st or 4wd either today.