Ever lived in a cold environment? You idle to let your heating system get up to temp. I grew up in a cold area and no way was I going to jump in my car right away in -20 degree temps.
Yes. Almost the entirety of engine wear occurs when the oil temp is too cold. By turning on the vehicle and immediately driving (conservatively below 2k rpms) you greatly reduce the amount of time it takes to warm up your engine oil versus when left idling at 500rpms. I learned this from reading the manual to my BMW and Subaru.
In -20 degree weather you won't accomplish much idling and should purchase an engine block heater if concerned.
I don't doubt you, but I know for a fact that by turning on my car and waiting inside I could get in and the car was warm. No waiting. Did this for twenty years.
You two are talking about different things. Frye is talking about warming the engine compartment; Epic is talking about warming the passenger space. You can warm the engine compartment more efficiently without idling by driving at low RPMs for the first few minutes; however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.
>however, idling is as (or almost as) effective as low-speeding driving at warming the passenger area.
Again, twenty years of turning the car on, going inside for 15 mins, and coming out and sliding into a warm car.
I'm not anywhere near knowledgeable enough to explain the details. I am fairly certain however that I was not hallucinating this throughout my entire childhood and young adult years.
The other advantage of idling is that when the windscreen is misted up, it doesn't matter that you can't see through it!
You can wipe condensation off, but I've always found it has a tendency to reappear quickly. Perhaps I'm wiping wrongly, but the only solution I ever found to work reliably is to leave the aircon and windscreen heater running until the inside of the windscreen has warmed enough to prevent immediate reoccurrence.
That's meant idling the engine in every car I've owned. Cabin heating never seems to run at full blast unless the engine is powering it...
Terrible pro tip: get in the car, start it, immediately start driving, but floor the accelerator and use the brake to travel at the speed you want. You'll have a warm passenger compartment in 1-2 minutes.
It's absolute hell on the engine though. Don't do this with vehicles that you are responsible for. This is mostly only applicable for leased vehicles.
The difference is that the heat is going the moment I get in my car. Not as efficient (and, to be fair, my experience is a bit dated here [~15 years]), but I don't have to freeze my butt off for 10 mins waiting.
This is ridiculous, I have never had a car need ten minutes of driving to make heat, even in a Pittsburgh winter. I have had a driving license for 36 years.
I drove a Renault Zoe around Stockholm in the middle of winter. Great car, except for the heating... takes a long time for it's little heat pump to warm up.
Is that an all electric car? Petrol combustion gives off a lot of heat, but if the thermostat is stuck open this works against the goal - modern vehicles will set a fault in this case because slow warm up causes more fuel to be burned and emissions to be expelled.
The difference is that your pistons, rings, bearings, etc have not come up to operating temperature and have not expanded due to heat. It's not going to explode immediately but you are reducing the overall lifespan of the moving parts if you drive on a cold engine.
Most modern cars are a lot more tolerant thanks to advancements in oil technology. But it is to a greater or lesser extent better to warm your car up, even if it's not immediately / apparently necessary to you.
You're not supposed to floor it and giver 6.5 when she's cold. Driving with low loads and low RPMs will bring it quickly up to temperature and produce minimal wear; I've been told it actually produces less wear as the engine runs less time/revs cold.
It's a different story if you're pulling a heavy load and can't do anything about it. Then letting her warm up makes some sense. Most people don't do that.
Yeah thats right. I build race engines as a hobby (currently have a cp-carrillo mazda BP in the works) and (I like to think) I have an understanding of mechanical sympathy. Obviously performance engines have different tolerances to mass-produced consumer items, but I like to treat them the same.
The benefits to slow driving is that it also brings the drivetrain up to operating temps as well - it's no good if the engine's at a good oil temperature but the differential and gearbox is still icy. But even letting the car idle for 10-20 seconds so it can push oil around the block, fill the galleries and start filling the lifters/head will help extend the lifespan of an engine, and then combined with a slow initial drive to allow everything to come up to temperature you should be able to give the car a bit more life.
It's actually illegal in Germany to do this. And yeah they sometimes get extremely low temperatures. In modern cars you are supposed to drive immediately which will warm things up more quickly.
And most of the rest of Europe too, certainly in Norway. And anyway modern engines reach operating temperature so quickly that most people have abandoned the use of engine heaters that used to be popular here 30 years ago (a 230 V electric heater in the engine block).
In -20 degree weather you won't accomplish much idling and should purchase an engine block heater if concerned.
Interesting article confirming what I am saying:
https://www.washingtonpost.com/news/wonk/wp/2014/12/29/the-b...