For years I've been averaging 23-25 mpg around town. After reading all the posts about going with a cooler thermostat, I replaced my trusty old 195 degree with a 180. Car runs about the same, but my mileage has dropped off about 3 mpg. The same thing happened to my '95 vette when I went to a colder thermostat on that thing too.

I kinda figured there would be a trade-off on something. Now I know. Anyone else experience this? I know, I know, guys who want more power and put there foot in it anyway probably are not the least bit interested in mpg; like...who cares? Right?

Ted

I didn't notice any difference in city or highway mileage after changing to 180. I normally only get 20 in town though.

try switching it back, the general concensus here is that the 180 shouldnt do that. Are your O2 and other sensors good?

No difference here, from 195 to 180 to drilled 180. I'm still getting nearly 30 on the highway.

My mileage decreased when I installed the 180. I was getting 18mpg in town...now I'm getting 14.5mpg. Not good. I recently had new wires, plugs and fuel filter installed. Thinking I should change the 02 sensor. If mileage does not improve after that I may go back to a 195.

Would we see any difference in mileage with a drilled t stat as compared to a non drilled?

I would suspect the O2 as well. You should be getting better than 18 mpg with either Tstat.

If I could drive without mashing the gas pedal so often I'd tell you what I've noticed.

I installed a 180 thermostat and I have my fans running 24/7 and the only time my gas mileage sucked is when I somehow unplugged my air temp sensor in my airbox and didn't know it. Other than that I am getting 18 to 19 MPG city

first of paul very ncie car....second...will how you get that much highway...i only get like 225 a tank thats like 13MPG