Warming up a cold engine

[Herb2]

I see that many posters believe that warming up a cold engine is pointless. I respectfully, disagree. One poster said, “idling an engine before you move is pointless.”

Cold starts are known to be the cause of 90% of engine wear. Idling causes next to no engine wear. Any time a cold engine is revved above idle, there is engine wear taking place, no matter how thin or synthetic your engine oil is. Therefore, warming your engine slightly before moving it and avoiding engine revving until the engine is at operating temperature, increases the life of your engine.

This being said, a cold engine will send only cold air to the cabin. Also, leaving your temperature setting on will use a little power and fuel. Therefore, I do advocate shutting off the temp control until the engine is warmed up.

Herb2

[trollbait]

"...warming your engine slightly..."

The majority do this, but they don't view it as warming up the engine. That phrase has been used more for warming beyond slightly.

The industry once thought that people were literally driving off the instant after the engine caught on. This lead to warnings about cold starts and letting the engine warm up. Then regular drivers were actually surveyed, and it turns out they weren't behaving like the industry thought. They were letting engines run for a moment or so that let oil get pumped everywhere and start warming up before putting the car in gear.

PS: With an efficient diesel, you'll be waiting some time for idling to get enough heat to the HVAC system.

[LDB]

I don't start and dash. I let my engine run and warm up while I place and secure my seatbelt and adjust the radio if needed. At least a good 2 to maybe 4 seconds. I'm sure oil has circulated across all lubricated surfaces by then.

I very VERY rarely exceed 2200-2300 rpm or wherever the shift points are and pointedly never within the first mile or two.

I also agree "warming up" doesn't likely mean the same thing now that it did 50 and more years ago. Then probably a very good and important idea. Now probably far less so.

[JockoT]

Cold starts cause engine wear but once the engine starts the high wear period is over. As soon as any condensed fuel is burnt off and the engine circulating oil. Sitting for five minutes with the engine ticking over just wastes fuel. I start my engine and within a few seconds I drive off. I keep the heater control set to cold until the engine reaches operating temperature then turn on the cabin heating. I understand why in Canada you may be willing to sacrifice fuel to get some cabin heat before moving off but it doesn't reduce wear on a modern engine.