I have the tranny cooler and live in southwest Michigan (the snow belt). Winter temps between 30 and -5 F, no problems with shifting. I do have the stock 195 F thermostat, however.

Hmmm. Got me thinkin actually... This will be my first winter with the 180 degree thermo and the tranny cooler. I've had the tranny cooler installed since I bought the car, but always like 95SESC mentioned with stock 195 thermo, and had no problems. This will be my first winter with the 180 all together. I guess if I cant get any heat, or I notice the tranny shifting hard I'll have to either cover the cooler(*), or maybe switch back to a 195 for the winter.

Anyone ever ran a good tranny cooler and a 180 in the winter where you get snow and 10-20 degree temps + lower ??

i dont know if its just my lack of car knowlege or what, but can someone tell me why having a 180 degree is sooo much better...

i asked my mechanic how muc hit would cost and he said "why the hell would u want one of them, your acr is fuel injected" he went on to showing me the difference between fuel injected and carourator engines and said ours would work best at 195.

...i dont know who to believe *puts shotgun to mouth*

Ok, thousands of GP owners and hundreds of Bonneville owners can't be wrong. Hypnos, change the thermostat, and if you're not satisfied, I'll personally write you a check for a new seal, stat, and gasket. Yes, I'm that sure. I'm willing to bet your mech doesn't drive a 3.8l. If your SC, it'* even MORE important. I got talked into it here on the forum, and I'm eternally grateful.

The 195 degree thermostat is mainly for emissions. A hotter running engine burns more cleanly then a cooler running engine but the cooler running engine will make more power due to the denser fuel/air charge.

Most cars that are running a lower temp thermostat are also using a modified chip to get the most out of the change in the fuel curve that the lower temp thermostat causes.

All cars from 92 and up do that automatically.

I live up in Canada and we have winter here 8 out of 12 months.. ha ha ha.. anyways.. my 2 cents is get the 180 T-stat.. and the thermostat gasket housing from your dealership parts store, and change it... the number one killer of most parts and the engine is heat.. so it'* a little safer in my opinion and protects those head gasket from getting messed up. You won't have to worry about taking longer for the engine to warm up since the thermostat wouldn't open until it reaches at least 180... by that time.. your engine would be pretty warm, and warm up time takes the same.