Has anyone ever tried running a drilled 195 t-stat? I have a 180 in my car already and when the switch for the fan override performance seems to drop. When I let my car heat up 200 or a notch over it runs better than having the fans on :? . I personally wouldn't think that running a drill 195 would hurt in the winter time neither.

Thats.....odd, your car should perform better the cooler the engine is, to a point anyway.

Perhaps theres another issue?

I'm not trying to make this a maintenance post but yea I just found out the day before yesterday when I click it off. My gas mileage improved also.

Right, our engines were designed to run hotter and be more efficient at higher temps. Why drill? Put in a 185 or 195 and go with it.

What'* the advantage/purpose of drilling the t-stat anyway?

If I remember correctly, to keep the car cooler by letting a little coolant drip pass the thermostat. The 2 holes are suppose to be 5/16 until you get into heavy modding.

I had a drilled 195 when I had my bonneville.

My buick currently has a drilled 195.

I believe it not only helps the temps a bit but also makes bleeding/burping the engine of air easier.

My primary reason for recommending that thermostats be drilled (I drill my winter 195 and my summer 180) is to provide a pathway for air to bleed out of the engine. I set the drilled hole at the highest (12:00 O'Clock) position in the housing to facilitate the egress of air to the upper radiator hose. These engines trap a lot of air when filled in a "conventional manner." That'* why we documented this procedure for filling. http://www.bonnevilleclub.com/forum/...=article&k=100