"Benefits" of Colder Thermostats
 

The Feb. 2010 issue of Road & Track magazine had a good discussion of the "benefits" of installing a lower thermostat. I thought that their comments were interesting since they support those of the SRT engineers in various Chat Sessions. Specifically, R & T was addressing a reader who wanted to install a 170 degree thermostat in his 2006 Corvette to improve performance. Here is their answer:

"Our thought is that someone is happy to sell thermostats, especially given all the talk about engines running better if they are cooler. If that were the case, then Chevrolet would have selected a cooler engine operating temperature. But they didn't and that's because everything from oil viscosity, combustion chamber temperatures, air/fuel ratio, heater and defroster efficiency, etc., is designed to run in the 190 to 200 degree range (often 193).

Of course, everything is a compromise and enthusiasts are quick to point to cooler intake charge air as making more power. True, but cooling the entire engine below its designated running temperature to eek down the charge temperature exacts a mileage, emissions, and longevity price for marginal power gains.

Colder thermostats have a place in hot rodding when significant power increases, most often from adding a supercharger, require greater reserves for momentary overheating. But in a stock or near-stock engine, the design operating temperature yields the best fuel economy, emissions compliance, and engine life."

I had hear that for normal road cars that it was kind of a myth and a waste of money. Better spark plugs would be a better choice like E3 if you want more power gains even if it is small.

I think this is the key part of the equation. If you have made radical changes to the operating environment under the hood, you may need the extra cooling. If the car is near stock, it will probably be most efficient at or near the intended operating temperature.

Very timely as I just purchased a "Mopar" 180 degree thermostat that was made for the SRT8 Challenger. My concern was its installation would trip an emissions check light. I asked several of the "go to" performance tech's at my selling dealership and they said it shouldn't be a problem going to 180. However, going down to say 160 or lower could/would trip an emissions light. I honestly don't see the harm going to 180 thermostat will do. Knowing all this, should I still install the 180 degree thermostat on my SRT8?

I guess it is good for the vehicles so it will not get heat.

Todays cars run hotter for Emissions reasons - theoretically burning cleaner at a higher temperature. The downside is the engine will heat-soak much quicker, your intake will be warmer, and fuel tends to detonate easier at higher temperatures.

as on i have i share on my observation ;)

It's work very well as a heat constant. i'm got benefit after use this one. it's save for the user epically for long run.

recommended to all to keep your vehicles and yourself in a safe zone.