IIRC Bob uses one. Don't know why he hasn't chimed in, but I could be wrong.

Cold starts can kill an engine over time. It takes a bit for the oil to get all the way through the engine even at warm temps. So I would say that if living up north then an engine warmer would be a good idea...so the engine internals don't go without proper luberication longer than they do upon warmer weather startups. Just my 2ó

Gun it and run it!
1981 CJ5,258,T-176,D300,AMC 20,Dana 30,Trxus M/T 31x10.50, Rancho 5000's, GroundPounderFab front bumper, polyethylene gas tank, aluminum dash, AutoMeter gauges

What this country needs is unemployed politicians.