Warming up the car before driving

[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.)

[Porschekid]

^That is true. I don't think I've read any car manual that recommends letting your car warm up first. It definately isn't harmful to your engine though, the slower your engine warms up the better. The danger isnt in having it operate at low temperatures but having the temperature rise at a high rate because all of your seals, etc. haven't had time to adjust.

[Adam]

^ I have to disagree with you PorscheKid. You want the engine to warm up as quickly as possible like john said. I think your logic is flawed no offense.

[aKiNa2]

when the car is started for the first time on a day it is good to let it idle for mebbe 5 minutes. In doing this it allows to heat up and lubricate the parts properly. Then drive off taking it easy until the temperature comes up. When driving straight form a cold engine, taking it easy will reduce damage but warming it up a little bit own't hurt. The most damage to an engine is during start up - and that is because the oil does not sufficiently lubricate right away. Hence the invention of oils such as Castrol Magnetic which claims to "stick" to parts to avoid this initial wear.