I was recently talking to a guy that really knows his stuff when it comes to mustangs. He was telling me a neat little trick to get some better fuel economy by running a colder thermostat like a 180 or a 175 or whatever. He said it would only be about a .5 mpg increase but that would still be worth it. Does this sound like it would work or has it been done?

 

.5? I wouldnt bother if youre just looking for mpg. I use a 180 but thats just more so to keep things cooler, not for mpg. I was always taught running a bit cooler would use more gas since you make more power that way, and to make more power you burn more gas, not less. So the more fuel burned, the lower your mpg. And that running a bit warmer helps with combustion, better use of gas as it burns more of it.

?

 

+1

 

In cases like this I'm always just assuming the factory picked the thermostat temp that's in my car for a reason lol

 

Its for emissions basically. A hotter thermo lets the engine get hotter so it burns the fuel more efficiently. It atomizes better.