[Dan Evans]

It's not that it loses power when it's cold. If you idle a cold diesel engine you varnish the cylinder walls.

Yeah, so I wonder why I often see diesel vehicles sitting around idling. Is there some kind of rumor going around among diesel owners that that's the thing to do?

[Fred Hayek]

In some really cold places (North Slope, Fort MacMurray, etc.) it's more to keep the engine oil fluid. I don't know if these locations have since switched to electric block heaters. With current diesels, it only makes sense in arctic conditions.

"If you don't think hell freezes over, you haven't been to Prudhoe bay!"