I have a 98 which runs real good. It was my father's since new and I bought it from him. I did most of the small fixes and maintenance on the truck, but he has had it at the shop a few times without me knowing what it was in for, and he does not remember much when I ask him questions now about fixes. Anyway, the truck does not get above 160 degrees on the temp gauge. I am betting this is effecting my gas mileage since this thing drinks like a pig. I have gone out and bought a new thermostat to replace the old one which I have not done yet. It also had a radiator leak in the past and has since been replaced, but in the meantime a few tubes of that powder stop leak stuff was dumped in.

So my question is, has anyone had any of the same symptoms or any ideas on why the low temp? My father does not remember if he ever had the thermostat replaced or not, but if so...I am guessing they went with something very low temp as a replacement?