Something I have noticed after I changed out the water pump and radiator, my fuel mileage has dropped a good amount and the engine also runs cooler now. My MPG's are down from 17-18 to 12-10. The temp gauge used to atleast hit the N in normal. Now the needle doesn't get near that spot.
I thought after a oil change and new fuel filter my fuel mileage might pick up a tick or so or stay the same. Not drop. I keep the truck under 2000 rpms and hardly ever go above 60 mph.
I am wondering if I have the wrong thermostat and its causing the engine to run cooler, resulting in less efficient combustion?
New T-sat was put in when I replaced the water pump. The link is to the T-stat I purchased.
Murray Caps & Stats 4269 - Standard Thermostat 1997 Ford F-250 | O'Reilly Auto Parts