Is it just me or is this whole 160 thermostat stuff wrong? I have the 160 and put in a 180 for the winter, car ran a lot better when fully warmed up. I have a feeling the car wasn't getting in closed loop which is definentally not good for performance. The way i figure is that you want the coldest air because it is most dense, but don't you want the engine warmer because it combusts the fuel /air mixture better thus allowing for more horsepower? I just dont feel that the 160 stat is a good idea for that and 2nd it probably doesnt let the engine get hot enough to boil water out of the the oil and certain other things.

Are the fans powerful enough to drop the temperatures significantly? Because if so, wouldnt it just be wiser to keep the stock tstat and just use the fans to lower it if you want. Thus getting the best of both worlds if thats what you want.

 

I would run the 180 in Michigan for winter, too. I do it even in Arkansas. There is virtually no chance it is not going into closed loop, though (unless you drive very short distances). ~140 is the temp it goes into closed loop.
If you don't want to use the 160, then don't.