I spent a few weeks with my uncle every year. He lived on the mountain in TN just west of the Tennessee Valley and worked in the valley for the railroad.

Sometime around 4 AM during the winters he would take a shovel full of coals from the wood stove and set it right below the oil pan on his 53 Dodge pickup. The truck started fine without the warmth he just didn't think the oil did its job at those temperatures.