I just replaced the thermostat on my 95 F150 and now it is getting around 17 mpg. Before it consistently got 15 mpg. I also had a 180 instead of the 195. Now I have the 195. It also seems to run better. It is a Duralast from Autozone. Is this a decent thermostat or should I go get a Stant? Also, should it really affect fuel mileage that much?

 

the correct op temp of the engine is 195, so you are on the mark now, hence the mpg increase

 

the computer likes that temp. anything lower and it will richen the fuel mixture causing pour mileage.

 

That's what I was thinking, so I guess that explains that then.

 

I noticed the same thing with the jump from a 180 to a 195. I just wish I had done it sooner.