What really happens when you run the car for less than five minutes??

I�m that guy. I don�t like to turn the car on to move it out of the driveway unless I�m planning on running it to full temp. All I can think about is all that condensation just siting in there rotting my poor engine away from the inside. But what really is the effect of turning it on, moving it out of the driveway, and turning it off. I want to be free of the torment!

Okay, a lot depends on the environment, but I've owned my car for 18 years and a day in Florida and put 154K miles on it with mixed driving. Sometimes I need to pull the car out of the garage and sometimes I need to drive to a local store. I have never had condensation in my oil.

Echoing Marv�s observation�it depends. Do you have proper injector function, Nikkies, UAOS, change oil every 3,000 miles? Why not start it when you want? You�re much, much less concerned with cylinder wash down and fuel seepage into oil. Is it cold and high humidity? You might get some condensation effect. After I put in new injectors and UAOS a couple years ago, I finally shook off the fear. I drive it year round in all weather and track it now. I do try to avoid multiple short trips out of habit. But that habit also trained me to find a reason to drive long enough to use the full rpm range following a warm up.

On cold starts of a 996,,, a flat 6, the Fi needs to be in heavy enrichment to keep the engine running somewhat smooth,, less, but even in Florida., It takes a lot of fuel for the 966 to smooth out when cold, imo to much. So the recommendation is to not let engine idle in cold start enrichment. Best to start car and drive away almost immediately after oil pressure stabilizes. Drive easy till the temp is up and cold start enrichment is off. When in cold enrichment at idle excess fuel can puddle in cylinders and wash oil off cylinder walls promoting bore score/wear, so they say... So drive off quick after cold start and the engine can better burn all fuel instead of letting excess fuel pool up in bottom flat 6 cyl. So, if you want to take car out of garage, start it and pull right out and shut it down. Might be a little fuel puddle in there at shut down, but at least you're not idling thru it. And hopefully it will evaporate by the time you restart it. Just don't sit there at idle with a cold 996 engine to let it 'warm up' like on a old carb engine. Anyhow, thats how the story goes for our m96. Not sure if its all true, but makes sense, especially if you notice how rich most all m96 engines smell on cold starts. Hey, it couldn't hurt to not prolong idle on cold starts and just quickly drive away slow, at least till you get some heat in the engine. jmo

A lot depends on the health of your engine at the time.....ie blow-by... For every gallon of gas burned..a gallon of water is produced...Water is the by-product of the combustion process... So....most of this water that is created by the combustion process goes out the tail-pipe as water vapor( steam) ... but what gets by the rings ( blow-by) goes into the crankcase/oil and when the engine is cold it will condense back into liquid water...This water from the blow-by will remain liquid until the engine reaches operating temperature then will revert back to steam again and be drawn through the AOS system and is re-burned as you drive at operating temps and finally be blown out the tailpipe.. As mentioned the fuel is rich on cold starts and the rich mixture can wash oil off the cylinders.....and also get passed the rings and into the crankcase ( the amount depends on how much blow-by and how rich) ...The fuel in the oil/crankcase will also vaporize into fuel vapor after the engine/oil reaches operating temps and will be drawn into the AOS system just like the water vapor and re-burned while driving the engine at operating temps... So, warn engine operation is ideal, but cold engine operation is less than ideal.....so the less the engine runs cold the better ..and driving off under part load gets the engine warmed up faster.. PS : cranking the car and pulling it out of the garage once a month is nothing to worry about.....but driving to work 5 miles away every day 100 times is something to worry about...

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Watch this video. The title say "When E85 sucks", but talks a lot about the by-product of short drive intervals. You Tube

the car blows up

Quotes source post: 19790470

The worry is real!

I wouldn't loose any sleep over it. A quick startup and moving the car around the driveway isn't a big deal. Especially in S. Cal. Skip provided a great technical explanation on what happens. If I can escape bore scoring in Chicago anybody can. All you gotta do is run damn good oil, keep it fresh, keep your injectors fresh so they spray properly and take a couple of extra minutes when driving to work or the grocery store to get the engine hot to burn off the fuel and condensation. Problem is many folks thought they didn't have to change the oil for 15-20k miles per Porsche and Mobil 1 and the cars sat with all kinda crap in the oil which didnt do the cylinders and pistons any favors. When they did drive it, it was for short stints using the bad oil and never got it up to temp to burn off the crap. Not there fault, they just didn't know any better because Porsche and Mobil didn't provide guidance. The 996 needs lots of fresh high quality oil and to be driven like you mean it when its up to temp. It will thank you with longevity. If you want to splurge on oil, try DI40. My engine sounds great on cold days at startup here in Chicago and seems to really like DI40. Just sent in another oil test to verify.

I remember an episode of Car Talk like ten years ago maybe, and they answered a question about the person who does a quick drive around the block to "move the fluids" on a car that is rarely driven. And they said in reality they were doing far more damage in that 5 minute drive than if they had just left the car off for the entire month. Because of the condensation that occurs. That was a great show.... now I feel old.