Yes, you can operate w/out a thermostat. But is doing so the best thing for the engine? Essentially, you're pulling more heat away from the engine than the coolant system is designed to do. The engine is running cooler. But is this a good thing? No. We've had some discussion on this board about this issue. The thermostat maintains the engine effluent water about 195 degrees F; supposedly, at about this temperature you engine will run more efficiently, improve gas milage, and with less wear. I'm sure some of the mechanics will eventually address your comments with better detailed information. Good post, and an important question. <img src="/forums/images/graemlins/kewl.gif" alt="" />