[rpcope1]

I disagree. The problem isn't so much that the cab isn't warm as it is that if the engine is way below the steady state running temperature (and thus the oil isn't yet lubricating real well), you're far more like to get boundary lubrication (among other wear and bad things) in the powertrain, especially if you load the engine up at all. It's worth it when it's cold out to let the engine idle for a couple of minutes just to save on wear.