I do warm my truck up! On the coast here, I often have a problem with my carb icing up if I don't, or if I don't plug the bus in.
Also, my bus sits outside in the carport, and I drive it every day, so, when its below about 8. I plug it in. I have a block heater (the cars and trucks came with them up here), and an oil pan heater.
After I start 'er up, I let it warm up till I'm off the choke, which is about 3 minutes or so. By this time, the Southwind heater has started to make nice heat (they advertised hot heat in 90 seconds-its true!!).
I also start out slow for the first mile, driving about 10 miles an hour.
When its below freezing here, I plug the truck in for a few hours.
