A colder thermostat allows it to open at lower engine temperatures, keeping the engine cooler and thus reducing horsepower-robbing KR (knock retard). We suggest 180 degree thermostats for mild/modded/performance applications, and 160 degree for straight race/high performance applications.
Posted by Victor C on 6th Oct 2015
I recently purchased this 180 degree thermostat for my 03 alero with the 3.4l la1 and wasn't disappointed. Some what of a easy install but worth it in the end. The stock 195 degree thermostat is just too hot for even slightly modified engines and hurts HP in the long run, would strongly recommend this part for your build!