iclick

I've read many articles on this subject over the years and the consensus among engineers and other writers is as you've described here. It also coincides with every owners manual I've ever had. In the 2015 manual read item 3 on page 9-22 (To Start the Vehicle). It's best to warm the engine in normal operation, taking it easy until operating temperatures are up to spec.

In the old days with carburetors and mechanical chokes cold idling prolonged the warmup process and would force a rich mixture longer than necessary. Doing that could dilute the oil with gas and cause raw gas to wash the cylinder walls of oil, neither of which is a good thing. The service manual of my C2 warned about that, which they called "crankcase dilution." That's not as much of a factor nowadays as today's EFI systems usually normalize the mixture quickly, so prolonged cold idle wouldn't pose the potential problems now as it might have in the past.

Foosh

There is no benefit in doing this. If anything, you're doing more harm than good.

Keep a battery maintainer on it, and leave it be until you intend to drive it again.

Zappa

tolerance. The space between the babbitt and the crank for instance, when metal is cold it's one size.....when warm it expands...since different metal contract and expand at different rates......you end up with more and less space between journals.....on the crank specifically now...when you put unnecessary forces by driving her, your taking advantage of the space between Journals....actually creating impact when the cylinder hits....when the engine is idling, the advance isent being used....therefore where the cylinder hits on cold metal it's not in the same spot on the crank that when the advanced spot hits under acceleration ......you don't want to put unnecessary wear in this advanced area before she's warmed up to the tolerance spects it's designed to run at.....
One last thing.....since we're talking about temps....everyone lives in varying climates....the Length of warm up time will very...here in Northern California my average time is between 5 and 10 minutes ........there are so many makes and models, all with different tolerances, like some of these overseas models.....there is no set standard.....I've got 5 to ten minutes to wait....I want mine to last.....I know.....I know in today's world everybody can't wait.....it's now...now...now.....so there's going to be those who will come up with reasons to NOT WAIT.....thanks for reading....Zappa

OnPoint

Just take it easy with the throttle and rpm until you get some oil temp (140-ish) before you start hammering on it.

If you want to toast a set of valve springs, spin a cold engine to high rpm habitually.

dbaker

Here's a perspective from Amsoil.

I think the key word is....'Excessive".

\db2

LimeRay

I give it about ten seconds after start up to let the oil circulate and then off we go. Keep the revs down until the yellow tach ring disappears.

2vetteEd

Actually, your are totally correct!

CCRed

There must be something wrong with mine.... When I start it cold and let it idle the temp climbs to 190. THEN it can go up to 225 and kick the fans on. Bad temp sender?

Zappa

4 min and I'm at 140....I'll bet you don't put your finger on your exhaust in two min....or...you live at the north pole...Zappa

Mrc100

I tend to keep at least one of my daily drivers for years and put some decent miles on them. My last SUV was a 2000 Durango and I got rid of it in 2014 with 300,000 miles one it. It ran great but I didn't want to replace the cadilitic converter so I sold it(it got damaged during an off road crash). I have another daily driver, 2007 Jeep Commander with 201,000 miles on it and it also runs great and I plan to keep it for 25 more years. Lol. Anyway, I idle the **** out of all of my cars. So I conclude based on my experience that ideling a car to warm the motor probably doesn't cause much harm. On the other hand driving away slowly provided the outside temp is not extremely cold probably doesn't cause engine damage either.

I'm convinced that there are studies and articles to suggest idling is harmful that are driven mostly from our environmental activist friends.

To me it doesn't pass the BS test and I don't know of any manufacture warranty denials based on excessive idling. We live in a time of fake news people.

Just for fun I'm idling all four of my cars right now.

Midnight08

Interesting topic. I think it's misguided to attempt to make this a one size fits all situations kind of topic since there are several variables that do influence the overall impact. For example, after several weeks of snow and no driving, the oil can be near freezing in temps. If I start it up, and get going right away, only driving three miles, in real low temps, then park the car for two or three hours, then drive it back home, the oil may never get to 100. Several days of that seems not too smart. For those reasons, I tend to warm up the car a bit (I like my oil temp to be around 60 before I get going, and then I still drive it easy. Ultimately, if roads are drivable, then I aim for at least one longer trip amidst the short trips, so I can legitimately get it going, as I'm not a fan of idling a car to warm it up. In general, I don't do it, with DD, nor truck, especially if driving enough to allow it to warm on it's own.

The other side of this is battery life. I'm used to driving my truck much of a day, then parking it outside of hotel, with over night temps around -20. No tender, no oil warmer, etc. and no problem starting up in the morning. Key point, though, is that this is in the context of the truck being driven allot during the day, so the whole truck is thoroughly warmed up, which means even with the cold temps, it's not like a vehicle that has sat several days in those cold temps.

How much a car gets driven is a practical variable in this discussion, as is how long the car has been sitting, IMHO.

Zappa

Too good......I have a1999 f 350 supper duty...437,000....just between you me and our Father....she's just starting to use oil....ok...I own a 1998 peterbuilt....I've only met one Diesel owner that dident warm them up....but.....there 18 to 22,000 to rebuild....I've got over a million on her.....I'll stick with warming them up..it's been fun chatting it up with ya....Zappa

Bill Dearborn

Oil leaves a lubricating film on the critical parts and the engine can safely be run at moderate power levels until it warms up. Even if what you said is assumed to be true it would still be better to drive the vehicle Vs letting it sit and idle for warm up as the dry spots could cause just as much damage during idle and there would be a greater chance of them occurring.

The only way to warm the engine quickly is to produce some power output from the engine. Idling only takes a couple of HP to keep the engine rotating and a couple more to power the electrical system. Driving at moderate speeds for the first few miles requires 25 to 30 HP which generates far more heat and greatly hastens warm up.

Bill

Zappa

Hahahahah...Dry spots....HaHAHAh...where do people learn these things.....once the pours are saturated actually impregnated with oil...there's NO dry spots......hahahahaha

Foosh

Pores, hahahaha . . .

Zappa

Visible at 30 power....grab a microscope you will see ALL metal has pours ...as the engine warms the metal expands....I hope you know that much.....this causes even more lubricant available

Foosh

I know, but you said "pours" and you meant "pores." However, molten metal does pour.

Zappa

Darn it...darn it....darn it......I keep forgetting I'm human....OH I know...at 150X "power"...you can see the oil pouring out of the pores....
My girlfriend gets dry spots.....my Vette....she's well lubricated ....

Mrc100

Why does the Corvette tachometer have a yellow and red indicator that is displayed when the engine is cold warning the operator of the dangers of turning higher Rpms on a cold engine? Why would they go to the trouble of adding this warning indicator yet did NOT provide any in car warning for excessive idling of a cold engine? Jeopardy music is now playing. Additionally, manufactures install remote start all the time knowing full well that this feature will result in cold engine idling. The answer. They are not concerned about it causing issues. If idling a cold engine was a concern remote start would not be a factory feature. Environmental activists and left wing media have worked hard to twist information to further their agenda and this is why we even discuss this ridiculous misconception. Can anyone point to any actual warranty claim associated with excessive cold engine idling? On the other hand I know many people that have high mileage trouble free cars that have been warmed up prior to driving since new.

DGXR

I have been driving away *gently* with cold engines for decades, with all of my cars (yes even those with carburetors), and never once had any issues. I wait until it's nearly full temp before hammering on it. This is a no-brainer. For anyone who's been paying attention at all, I can't believe this is still a topic of conversation.

With race cars or other special applications, there may be good reason to idle up to temp before actually using the motor power. Or, for those who insist on using full power as soon as they get in the car, then yes you should warm it up. Otherwise there is no real benefit.