180 degree thermostat in a 89 chevy truck 350 tbi motor. i have heard that is bad. i heard i would get worse gas mileage and worse performance.. is that true?? stock thermostat is 195...btw the truck is stored in the winter..never driven in winter

 

if the thermostat needs replacing then go for it...

 

No you will actually get better performance and your gas mileage difference is too infinitesimal to matter. with 160 degree stat you would have to worry but not for 180. I put a 180 in mine and didn't notice any difference. I figured that with an engine that old it probably doesn't need to run as hot as it did when new.

 

Stock is a 195 correct? If you run a 180 it could hurt your mileage a little, but not enough to matter. Now a 160 will cause the truck to stay in the warm up cycle causing it to run rich I beleive which will cause bad gas mileage. However if you runa chip that needs a 160 like i Did when I had my 90 model 5.7 with the Hypertech Thermomaster. It did not hurt my mielage... if anything it seemed to increase it.