A colder thermostat is an inexpensive way to lower engine temperatures. Cooler engine temps reduce KR and promote cooler intake air temps. Our thermostats feature openings 20% larger than stock for increased flow.

We also offer modified thermostats for increased performance.

Drilled thermostats- The car will still get up to the temp that the thermostat is but it will take longer.  The gain in it taking longer is when your car is sitting(not running) it is cooling down.  When you restart the car to race it

A 180 is the coldest stat is recommended for the N/A 3800. Using a 160, the PCM commands too rich of a fuel mixture.

A non-drilled 180 stat is recommended for the 2004+ GPs, 2000+ Bonnevilles and Regals or an engine code can be set.

If you want to run a colder stat on a newer vehicle you may need to run our Estat.