Will a 180* stat hurt my fuel mileage?
 

I'm thinking getting one this summer, and wondering how much/ if at all it will hurt my MPG's

Thanks.

There's a big debate going on over on ClubGP on this right now. Some say it does, some say not. I have seen no compelling documentation one way or the other.

Although I have not done a perfect A / B comparison (that is, no other changes at all) between 180 / 195 in my 1998 LeSabre, I believe the 180 T-stat is dinging me for about 2 mpg in my mixed city/highway driving (i.e., daily commuting), while allowing me to advance timing (with tuner) a few degrees. I'm getting a consistent 17-18 mpg, where I think I should be getting 19-20. I believe this mpg loss (if I can confirm it) may be because the fuel is not atomizing as well when the engine is not heating up as much.

I don't believe the 180 T-stat is having any measureable impact on mpg's (or timing allowed) on long, cruising highway trips. There I get 32-35 mpg, depending on how packed the car is (far less of course when we have six people in the car, the car-topper, are towing the popup, and are heading to Big Bear / Tahoe, etc. )

I plan to go back to a 195 degree T-stat in the very near future, and see if my mpg's go up. If so, I'm sticking with 195 and getting a bigger aux trans cooler. Gas prices are such that a few degrees of timing advance isn't worth a maybe 10% loss in mpg on the driving I do >75% of the time :cry:

hmm, interesting, well, once i get paid ill probably try it and see how it does. the reason i want it is that my blazer runs terribly hot and it worries me, but who knows how accurate my temp gauge is :roll:

I have seen the difference between a 180 drilled and a stock 195 and mine drops about 2mpg. I tested drilled 180 to drilled 160 too, no change in mileage.
Testing was highway only, 120 miles between gas stations.

Golden you try it? Interested in the results you figued out.

the stock on is just fine. if a 180 or 160 would have been better it would have come from the factory with one.


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