Reving a cold engine



My husband and I have an ongoing discussion about what you do when you start a cold engine. Is it hard on the engine to rev or drive fast a very cold (weather 30 or below) engine? Or is their an argument for letting the engine warm up before driving?


Like many questions, the correct answer is in in the middle.

Sub 0? You want to start it and let it idle or give it a little pressure on the accelerator just enough to keep the engine running. Keep that up until it runs OK by itself without any pressure on the accelerator. I would let it idle while you clean off the windows adjust the seat etc. Just give it a minute or two until it will move the car OK.

If it is 30?F above then you will not likely need the above.

Next 30? above or after you have done the above you want to drive it without revving the engine very high for the first mile or two, until the engine is running normally and the cold engine light goes out.

Many people like to warm it up by idling it longer either because they want to get the cabin warm (I guess they are going back inside the house) or they believe it is better for the car. It is better for the car to actuarially drive the car at reduced speeds to warm not only the engine, but also the transmission, suspension, tyres etc.


Drive it kindly until it gets to operating temperature. But there’s no need to let it warm up beyond giving it 30 seconds or so for the fluids to get where they need to be.

Engine parts are designed to be at their optimum size and shape at full operating temperature. The dimensions change with temperature. Because of variations in materials, shapes and dimensions, they don’t all change exactly the same. While the differences are not enough to worry about if you don’t push the engine when cold, they certainly can reduce the life of the engine if you do.


Cold is 0F or lower. At 30F your oil still flows easily and the oil will circulate in the engine in about 15-20 seconds. As others recommned, drive off gently and let the load on the engine warm up the car much quicker.

One reason the government environmental guys say drive off right away, is because it causes the least overall air pollution at the expense of some extra engine wear; but you are interested in the lowest engine wear.

So, at 0 degrees F or lower, you need the engine to run smoothly and also be able to see out of your windows.


Start the car . . . count to 30 . . . put it in gear and drive away . . . drive carefully and gently for the first 5 minutes . . . let the whole car (suspension/transmission/brakes/engine) . . . all warm-up easy. Remember that stuff breaks easier when cold, the molecules being closer together and all that stuff. Works for me, good luck! Rocketman


Some parts of an engine get lubricated long before others. Reving a cold engine is NOT good policy…The piston skirts, rings, cam lobes are all still running dry…You can overcome some of this by using a 0W-30 synthetic oil, which will flow to these critical parts much quicker than mineral oil…Most engine wear occurs during cold start-ups. Why compound the problem by reving the engine??


Only a idiot would rev. a cold engine


I remember the car salesmen doing it all the time when I worked at the dealership. Rocketman


I’m not surprised.


Yes, it’s hard on the engine to rev it when it’s cold. Let it warm up for twenty seconds or so, then drive gently until the temperature gauge hits the normal position if possible.


Yeah . . . that’s my point, and it drove me crazy to see the salesmen do that. Wasn’t their car and they didn’t have to fix them, only sell them. I have an old Honda Accord, an '89, with 506,000 miles on it and I’ve used the procedure described above since brand new, no problems, still runs great. One of the old mechanics once told me to start it and drive it like it was made of glass until the whole car warmed-up and it will run forever. Maybe? My vote is to warm things up slowly and then just drive carefully. Rocketman


Wow, good job, rocketman!