Why not Idle to warm engine?

The manual states "Do not let engine idle to warm up." Here in the north just about everyone lets the motor idle to warm up, in fact a lot of people have remote start for just that reason. Does anyone know why Porsche does not want us to do that?

I don't know their reasoning for sure, but my guess would be a few reasons - 1) It's OK to drive the car while it's warming up as long as you don't rev the motor past about 4k rpm until the oil gets up to temp, and 2) it's a waste of resources to let the car sit there and warm up without driving it - your effective mpg goes way down, and 3) driving the car while it's warming up warms up the CATS better, making them more efficient - and there's less pollution as a result. On the other hand, quite often I let the car sit and warm up properly before running it in a track session or an autocross, and it doesn't hurt the car to do this. brad

No car manufacturer wants you to do that. Idling may warm the engine, but does little to bring the rest of the car's moving parts up to operating temps. E.g., warm engine + cold, sluggish transaxle = excessive wear.

Not only Porsche, any car need to warm up other components like transmission, not only engine, and the engine itself won't warm up correctly idling.

It takes 3 days for the engine/oil to get warm at idle.

and your cats aren't effective the whole time.

In this part of the north (west) everybody and his dog have the couch potato starters too. Heaven forbid putting some decent cloths on and getting some exercise. You'd swear to God that everybody was 95 years old. And idling does not get all the necessary parts up to operating temperature. In fact, in low enough temperatures the bottom of the motor can be at ambient and the top end is hot and nothing is circulating. Lovely conditions for a motor to work in.

Remote starters are less about heating up the engine & drivetrain. They're more about getting the car's heater working so the occupants can go from a warm house to a warm car. I doubt there's a moment of thought given to the car by 99% of the (non enthusiast) population. It's all about creature comfort.

I thought I read somewhere that some sort of (sulphuric?) acid is created during the initial startup/warmup period and that the sooner you can get the motor up to operating temperature the sooner the acid is evaporated and no longer wearing out parts..... so the long idle at low temperatures can result in more engine wear than a more rapid (under gentle/medium load) warm up. Nick

********* Why waste gas on warm up? I drive off as soon as the engine goes off high idle. Keep the revs below 4000 for the first few miles. I get get heat or A/C in the first 1/4 mile.

Thanks for all of your good thoughts on the subject.

This isn't saying to gt into your car and as soon as the key is turned put it into gear and drive off? Cos I idle till the rev's drop and then and only then drive away. It drives my wife mad sitting in a car for two minutes with me smiling at her but I do the same thing in her car(Subaru Legacy) and my commuter(Golf GTI) so I'm consistent. Its funny cos she's the one who says that she wants to drive her car into the ground and I tell her it'll be sooner than she thinks if she doesn't show a little mechanical sympathy. Please don't tell me I'm wrong or I'll never hear the end of it G.

Push in clutch put car in reverse insert key start car pop clutch buy new garage door!

Now you will hear the end of it gmorat, no more wife driven mad and your engine will have less wear at start up if you just drive straight off N

x2, except when it is super cold (10 or more degrees below zero) I'll let it run for 20-30 seconds before driving. Here's a good compromise for you. Buy your wife a block heater. Then you can just unplug, start the engine, and leave immediately with a clear conscience.

All of the above for just getting in and driving (gently) off. The combination of modern oils, catalytic converters and electronic engine management make this the preferred methodology. The supposed increased wear from driving off ASAP is mitigated by the fact that there is less unburned fuel from prolonged idiling contaminating the oil. The long warm up of days gone by was the result of the car being undriveable without it.

Balls. G.

We did this subject a couple of years ago but Club membership is much greater now so repetition ok. !) I don't believe warming of other drivetrain components is very important since their warmed operating temp is not very high,compared to engine, anyway. 2) Manufacturers are wise (required?) to tell us whatever will minimise emisions. 3) A major reason we should limit cold idling has to be piston ring/cylinder wall lubrication. Whether rings get lubrication only from oil thrown from rod bearings, from oil that reaches them via drilled connecting rods and the wrist pin, or even from oil jets, they won't get as much oil in a cold engine at idle as they will at some higher rpm. This is a critical area of metal-to-metal sliding, flame-bathed surfaces and the period of inadequate lubrication at start-up is best minimised.

i fire my up with my head turned toward the back of the car. as soon as i have ignition, i am backing out the garage. first 3 min, 4500 rpm as i haven't figure out how to keep it under 4500 and not stall the car ;-) by the time i get to bottom of hill (10min), WOT and off i go. i dont have that extra 5 min in my daily routine to warm a car up. i got too many things to do, surfing CC is top of my list.

Just drive gently at the start and everything will warm at about the same time including the great seat warmers. I live in So Cal most of the time and still love the seat warmers. When my back is bothering me I use the seat warmers and the air at the same time. It good to be decadent at times.

It has to do with oil circulation, when a car is idleing, the oil is not properly sent up(or in this case, across) the cylinders, and alot of ring wear is created. on alot of cars, the oil is barely distributed at all when at idle, though I don't know how a dry-sump affects that

My style is...start the car, wait for the automatic high idle to kick down, and drive off. If it's real cold, there seems to be two stages to the idle.

Here is an interesting read on the subject. Similar to what some of you said above. Warm up the car by idling - Great Moments in Science - The Lab

I guess you guys up north like global warming