Thermostat stuck affecting gas mileage?

[cbehrenwald1988]

I just bought a 2004 Grand Prix and noticed I'm not getting very good gas mileage (18 mpg driving @ 65 mph). The check engine light came on a couple times briefly so I took it to autozone. The reading came up that my thermostat was stuck open and overcooling my engine. I was wondering if the engine being over cooled would affect my fuel economy due to the engine not getting up to temp to properly burn gas. Anybody else have a similar problem or input?

 

[Scottydoggs]

sure would, change the t stat, its 10 bucks. get a 195 deg one. it may come with a new o ring, if not buy one as well.

 

[dsmuts]

Yep run a 180* if you plan on modding a lot.

 

[SlowNA06]

Yep run a 180* if you plan on modding a lot.

Or don't. And honestly, for $10 and 10 minutes of your time, it's a bridge to be crossed when necessary.

 

[dsmuts]

I just like my engine to run cooler so I always run a 180* but it's more personal preference than anything.