Warming up the car before driving

[Porschekid]

I try to give it atleast 5 mins or so to warm up in my driveway if it's the first time being driven all day. I can't see it causing any harm. Alot of car people do this... especially in colder weather.

[Adam]

I really think the most important thing concerning warming up is to be very gentle on the engine until it is fully warmed up. You will extend the life of the engine by following this rule. The oil cannot sufficiently protect the engine until it is warm and dispersed evenly on all the moving parts. I learned this the hard way when I hot-rodded my old 528i when it was cold. Broken lifters aren't fun. My dad's M5 has nifty little lights on the tach that gradually disappear to let you know the safest maximim engine speed as it is warming up.

[Brucelee]

Adam is so right. In addition, in those Northeast Winters, you might try using Mobil 1 0-30MPH. Should help you get a bit of extra MPG also.

[Perfectlap]

why doesn't Porsche just say "let warm up for a few minutes in extreme cold"?
Instead they say drive the car right away, no exceptions mentioned.
I'm thinking there must be some rationale for this.
Perhaps Porsche believes that an engine sitting at idle is worse than cold moving parts.

[Adam]

I'd say your fine either way..just use your best judgement.

[Ronzi]

Not that I know anything about thermodynamics, but I suspect the Porsche recommendations (and they are not alone in these recommendations) have to do with the aluminum alloy block and heads, the viscosity of synthetic oils at low temperature, and maybe even the way the fuel mixture is maintained by the ECU.

Since aluminum transfers heat much better than a great lump of cast iron, I suspect the engine block and heads come up to operating temperature very quickly. Modern synthetic oils also maintain their pourability a very low temperatures, so there is less need to actually heat the oil a whole lot before putting the engine under load.

Computer controlled fuel mixtures and ignition settings also reduce the old problems of excessively rich or lean mixtures dependant on temperature, so engines just run better when cold than they used to.

[Perfectlap]

I agree with that fully, new engine materials and design changes conventional wisdom.
Now what's to be said about Porsche warning against an engine sitting at idle for a few mintues?
Is there some danger that this practice done on a daily basis could lead to problems down the line?
I'm going to check with my service manager and see if he's heard anything on this topic.

[John Y]

Originally Posted by Perfectlap

I agree with that fully, new engine materials and design changes conventional wisdom.
Now what's to be said about Porsche warning against an engine sitting at idle for a few mintues?
Is there some danger that this practice done on a daily basis could lead to problems down the line?
I'm going to check with my service manager and see if he's heard anything on this topic.

Yes, because as I said, by letting it sit for a few minutes, you are prolonging the period in which your Porsche engine operates BELOW it's normal operating temperature. Starting it up, quickly followed by gentle driving is the quickest way to get your motor safely, up to operating temps, which is what you're aiming for.

Every owner's manual I've ever had previously - (all were VWs and Audis), have recommended this method, for fuel economy as well as engine longevity. Had nothing to do with materials either, they were all iron-block motors and ran on mineral oil from the factory.

[RandallNeighbour]

Perfectlap, do not forget you are reading a manual written by a large company in Germany who is working very hard to be politically correct and ecologically sensitive.

Germans are sticklers on clean air nowadays (didn't use to be like this, but the damage caused to the black forest by automobile fumes changed everything) and I would not be surprised they put this in the manual just to cut down on the amount of exhaust fumes in the air.

Read any greenie's list of things to do to save our planet and you'll see right up on the top of the list:

"Do not warm your car before driving it. This causes unneeded pollution."

That's my read on this... we could toss around mechanical and performance and long wear comments all day long, but in my opinion, it's all about keeping the conservationists happy.

(Note: Conserving natural resources and protecting our environment is important to me! I'm just stating why I think that line is in the manual.)