During the summer the engine temp was always around 175. As the temps got colder, it seems that the engine never heats up. After driving for about 2 hours in 40f, the engine temp gauge hardly moved. I'm not sure if the gauge is at fault, if these temps are normal for winter, or perhaps the thermostat needs to be replaced. Since most people don't drive their spiders in the winter, its been hard to find information on this. The heater usually starts to work after about 5-10 minutes of driving. Any thoughts would be appreciated.