Easy and in two words: Dimensional stability. Alloy engine cases move around quite a bit while warming up. It is not at all unusual for an M96 to have its cylinder bore dimensions move more than a couple of thousandths from stone cold to fully warm. Other parts of the cases move even further. And if the engine is "loaded" (read moving the car) during this period, you are subjecting it to unnecessary wear due to the alloy shifting. So you can protect the environment, or your engine; choice is yours............

http://tapatalk.imageshack.com/v2/14...f0b54a2dde.jpg

Why don't you get one these you hippie ;)

Joking aside to my knowledge porsche is a fairly enviro friendly company even back with the 9X6 cars.

This discussion reminds me of another principle I have been told about engines, though probably more important with turbochargers: Always allow your engine to cool down at lower load/rpms before shutting it down. A hot engine being shut down immediately without a good cool down is probably more thermal stress than a cold start and traps oil where it may break down more or coke. (I am more familiar with aircraft though)

JFP.

Great response.

But the evidence based on immediate max power and racing revs is somewhat different than the 3500 RPM limit until 12 miles and warm I was describing in an every day car. Or is it? How much is enough? In racing every HP counts. But do I care if I lose 2 or 3. I'll still make it to the grocery store.

Is there any system in our cars that pumps/sprays the oil and delays the start for a few seconds to get the oil flowing? You would think there should be given what you describe.

The thermostat limits the water cooling until warm. The oil/water exchange helps warm the oil. The side air exchange fan doesn't come on till the engine compartment is hot. All show Porsche thinks quick orderly warmups are important. Is there any other system?

Sisu. Agreed. I'm just trying to establish the degree.

I used a rev limit until warm and even then I didn't hammer it. Is that enough or do we need heated garages and to what temp? Block heaters? Fluid heaters?

(Lets limit the discussion to moderate (28f to 100f) temperature climates with 0w-40 oils. Alaska is just different.)

Mike - I think you are correct, but there are too many variables to be able to draw positive conclusions regarding what we need. Even measurable differences such as oil & coolant temperatures @ startup, individual bore ovality, engine bearing and piston ring wear and oil quality as well as engine revs at low temps all come into play here.
High engine speeds with a closed loop (rich) fuel mixture is detrimental to longevity, but I would have thought that high load and low revs on a cold engine would be just as detrimental if not worse...

Having owned several Alfa Romeo cars where warmup was general practice, I still tend to warm my cars for a couple of minutes and then keep revs below 3,000rpm and (importantly) engine loads low for the first 5 miles or so....

Sorry guys....but a simple google search reveals FAR MORE pundits backing the 30 seconds and you are good to go theory. Yes, many touch on the different metals and such that comprise an engine, but as long as you aren't putting your foot down, you will warm the car much faster driving it and therefore, bring the entire engine to temp faster. Just be cautious with your gas pedal. I'll keep motoring along like this (as I have for the past 20 years). YMMV of course.

https://ca.autos.yahoo.com/blogs/green/8-facts-myths-warming-car-winter-201000465.html

Hey, I'll be a hippie any day if I get to drive this beauty!!

Gee, it seems that this discussion is turning back to the "I read it on the Internet so it must be true" rather than listening to the people who actually have seen the hardware!

Engine designers try purposefully to raise the engine temperature AND oil temperature as fast as possible to try and bring everything to equilibrium. All to reduce wear and friction.

If we want to bring the environment into it, with a closed loop control system like most modern cars have the A/F ratio is controlled very tightly. If you were to calculate the total emissions you would find them lower at idle and low speed due to the much reduced air flow through the engine!

So.....warm it up and take it easy by whatever method suits you. It will only help, not hurt. IMHO

Mine is Tip so I give it a bit more time. Seconds not minutes.

Mike, the entire point is about component wear due to dimensional shifts as the engine heats up. All alloy engines move around quite a bit as they warm up, enough that astute machine shops actually do their work on the major engine components only when they are at normal operating temperatures, which is where they spend most of their lives. And the dimensional differences between running temp and normal room temp are considerable, enough that engines prepped this way actually make more power because everything is where it is supposed to be at temp. Add in the high thrust angle inherent in the flat six design, plus the poor film strengths inherent in 0W oils, and you get excessive piston and cylinder wear (scuffing), which becomes even worse on DFI versions.

Coolant heaters, which are often used on race engines, greatly reduce the wear caused by dimensional stress induced wear that cold starts result in. Heated storage is always a plus for any vehicle, even for components outside the engines or drivelines, but normal storage temps (55-60F in our storage facility) is not warm enough to dramatically alter the engine warm up wear patterns. The coolant needs to be 150-170F to make a real difference.

Because of the differences in wear patterns we have seen, if a customer asks our recommendation, I would tell them to let the car sit and warm up at least until the heater starts to blow warm before moving the car, and then take it easy until the car is up to temp.

You can follow what ever "pundits" you please; in the end it is your car and your money. Based upon years of real world example's of what these engines do, we will continue to tell our customers to warm them up before driving them.

As always, you are terrifying me, and my Boxster lol

I'd like think that the design team in that Stuttgart's studio have gauged the correct low & high expansion characteristics when it came to selecting the flat6's materials. Wear is beautiful, shinny and even, when engineered correctly.

As long as you don't quenched the hot engine in cold water, it should be designed to scuff to Porsche's tolerance/acceptance. Cold or hot - stop terrifying me, and others maybe lol

We get full AL/TI engines warmed up to 95degree (203F) before revving them (superbikes, manual thermostat!). What do you tell your customers is the acceptable go-temp range for the stock flat6, or your custom built?

All predominantly alloy water cooled engines suffer from these dimensional shifting issues, so your Porsche is not alone in this area.

For a factory engine in a street car, minimum is to warm the engine until the heater starts throwing heat before driving. For a performance rebuilt engine, again on the street, warm it to at least 150F (assuming aftermarket gauges). Race engine should be 160-175F.

thanks

Dunno about you but seconds feels like minutes when warming up my little Porsche car here lol

Won't lie I've often turned the key, put on the seatbelt and GO. Just can't wait.....

kids huh

After reading this thread, I'll leave a couple minutes early in winter and let it warm up.

I slowly back out of the garage and wait for the door to close. That's enough. Then I keep it under 3000 rpm until the temp gauge moves a bit. I also do that with any car including my H6 Outback!

People either forget, or are not old enough to remember the US automakers first alloy engine cars; Vegas that never needed an oil change because they burned it too quickly, late 1980's GM V8's that consumed coolant by the gallons if you didn't add a bunch of cinnamon based tablets (yes, you read that correctly) to seal up the head gaskets where they leaked because of dimensional shifting when the car was warming up, Mopars with more coolant in the oil sump than oil, etc.

None of this is anything new.

I always wait for temp to get up to 180 before driving off.

I remember a similar tread when I first got my box a couple years back. I was letting it warm up until the temp needle began to start rising. There was, in that discussion, the fear that that kind of idle time allowed more moisture and gas into the oil and that was certainly not a good thing. Now of course if you drive 30+ mins at temp those extra ingredients should burn off.

Next time I start i'll time how long it takes for warm air to start blowing
All JFP's explanations about mechanical readiness is what initially prompted me warm up longer.
Might be coming full circle on this subject
Time to break out the Bell bottom pants

Why you hate the Earth, bro??