Warm the engine driving or in the driveway?

[Mark_T]

Yet Porsche, in the owner's manual, specifically states that you should not let the car sit and idle when you start it and that you should immediately drive off. There must be some reason for them to make a point of saying that.

[shadrach74]

Is there any scientific basis for the 2500rpm number that has been posted a number of times? Just to be clear we are running modern engines, with modern synthetic oils (hopefully)... I can see no logical or scientific reason to stay under 2500 RPM. If the system has oil pressure, then there should be no metal to metal contact. Certainly full throttle or Red line ops are a no-no until the fluids are warm, because that may generate oil pressures that are higher than factory parameters. Also, in extreme temps, dissimilar metals contract and expand at different rates. Metal to Metal interference form this phenomenon is highly unlikely, but is still something that we should keep in mind.

2500, 3000, Idle...whatever. The factory says 4K is the limit cold and there is likely some scientific reason for that...other than someone on an internet forum said it once and 25 people repeated it.

[tonycarreon]

Originally Posted by shadrach74

...

hah! you mean everything on the internet isn't true?

my procedure:
1. open garage door
2. insert key and turn to on, until oil check is done (or chime stops, whichever occurs first)
3. start engine
4. pull out of garage
5. drive away hoping the garage door closed
6. drive to the highway onramp, 1.2 miles from the house
7. resist the urge to have fun for another 4 or 5 miles
8. usually fail

[tony_fury]

Originally Posted by tonycarreon

hah! you mean everything on the internet isn't true?

my procedure:
1. open garage door
2. insert key and turn to on, until oil check is done (or chime stops, whichever occurs first)
3. start engine
4. pull out of garage
5. drive away hoping the garage door closed
6. drive to the highway onramp, 1.2 miles from the house
7. resist the urge to have fun for another 4 or 5 miles
8. usually fail

I think item #6 is the problem causing item #8 to fail..
You need to move, you live too close to the on ramp...lol

[stephen wilson]

#5 is funny! I would change that one. Once or twice I hit the remote twice, leaving the garage open all day, facing the street, inviting anyone to rob me. Now I wait until it's fully closed before pulling away. So I guess I do Idle for 1 Minute or so.

[BYprodriver]

Originally Posted by Mark_T

Yet Porsche, in the owner's manual, specifically states that you should not let the car sit and idle when you start it and that you should immediately drive off. There must be some reason for them to make a point of saying that.

I agree. The reason they say that is to minimize emissions by warming the catalytic converters as fast as possible, after all Porsche has to warranty emissions parts for 8 years. Also vehicles get very low MPG while motionless.

[Topless]

Originally Posted by BYprodriver

I agree. The reason they say that is to minimize emissions by warming the catalytic converters as fast as possible, after all Porsche has to warranty emissions parts for 8 years. Also vehicles get very low MPG while motionless.

Yep, also idling the car while stone cold tends to load up the cats with rich mixture carbon. Then the car runs lousy and the cats fail prematurely. Just get in and drive.

[BYprodriver]

Originally Posted by Topless

Yep, also idling the car while stone cold tends to load up the cats with rich mixture carbon. Then the car runs lousy and the cats fail prematurely. Just get in and drive.

Aced my smog test yesterday, 102,000 miles on my original cats.
I prefer replacing cats over engines.

[Topless]

Originally Posted by BYprodriver

Aced my smog test yesterday, 102,000 miles on my original cats.
I prefer replacing cats over engines.

I guess we have both seen good success using different warmup techniques (102K on original motor and cats) so it really doesn't matter much, at least in SoCal. Ultimately it is your car and your $$ so do what you feel is best.

[BYprodriver]

Originally Posted by Topless

I guess we have both seen good success using different warmup techniques (102K on original motor and cats) so it really doesn't matter much, at least in SoCal. Ultimately it is your car and your $$ so do what you feel is best.

My warmup procedure varies depending on several variables, but when I rebuilt my engine, during the breakin period it idled a long time before it moved.

[jaykay]

From cold, I try a time my move off until after thewhine form the secondary air pump (I think) dies and seeing the temp needle move off...a little...this maybe a minute or so

My rationale is more gradual even warming of the aluminum heads. We all have heard of the cracking issue yes?

[tranceatlantic]

here's my 2 cents:

Idling may be less stressful for the engine but will require more time to to reach normal running temp. Driving is harsher but the engine will warm up faster. I would suggest driving gently until the engine has warmed up.

[san rensho]

Originally Posted by BYprodriver

I agree. The reason they say that is to minimize emissions by warming the catalytic converters as fast as possible, after all Porsche has to warranty emissions parts for 8 years. Also vehicles get very low MPG while motionless.

Yep, the Porsche recommendation to drive immediately is based on emmision and MPG concerns, it has nothing to do with engine longevity.

Its indisputable that there is exponentially more wear on an engine at cold temperatures, and the more load you add at cold temperatures, the more wear.

See HOTRODSRJ’s COOLING TIPS Operating temperature vs power and longevity!

Now I don't recommend idling the car until it reaches operating temperature, although that would minimize engine wear, but idling the car for a minute or 2 or 3 is much better for the car than turning the key and driving off.