synthetic oil

My 86' carrera has 100plus miles and no oil leaks. Actually a little bit of sweating around cam lines. I'm thinking of going to a synthetic oil but I'm worried about leaks popping up. If they do will going back to conventional oil stop leaks.

Synthetics will not cause leaks !!!!!
I changed to synthetic oil in my 83SC when the car had 150,000 miles on it ! I have put nearly 40,000 miles on her since changing to Redline synthetic and she didn't leak when I bought her with Valvoline and she still has no leaks now with Redline synthetic.The car run cooler and better with synthetics.

Best advise I got when posting the same question on the Rennlist was:
"If the motor is oil-tight before using a synthetic, it will likely be so with a synthetic".
This has been true for my car, using Mobil 1.
Can't say for other brands of synthetic oil.

Also there is some evidence that early
synthetic formulas were based on chemicals that made older seals and gaskets too soft, and thus, leaky. This should no longer be a problem with the latest oils.



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Doug
'81 SC Coupe (aka: "Blue Bomber")
Canada West Region PCA
members.home.net/zielke/911SC.htm

I used Castrol 0W-30 and now use Mobil 1 0W-40 in my 142000 kms 3.2. I have not experienced any oil leaks.

Mikkel,
the weights avaiable in NA are different from thgose available in Europe. It is almost impossible to find Mobile 1. in 040 here, 0/30 and 5/30 are available but not recommended other than for use in the deepest part of the winter in northern areas.

I've been using Mobil 1 0w30 on my 86 Carrera and live in northern California where winters are mild and haven't had any problems.

Joe

The factory does not reccommend such light weight oil in that environment

Originally posted by Bill Verburg:
[B]The factory does not reccommend such light weight oil in that environment

I live in eastern Iowa, and my mechanic recommended 15w-50 all year; I use Mobil 1 15w-50, and during the winter I add a quart or two of 5w-30. I do not have Bentley with me, but I think it does not recommend 30 weight oil for ambient temperatures over 50F. A "zero" weight oil is only necessary if the temp goes well below 0F; I think a 5 weight is good for minus 10F.
I recall a posting on the 356 list a while ago that said to avoid 5w-50 because its lubricating properties are lower than a narrower range oil, though still better than standard (non-synthetic) oil.
The owners manual for my Audi A6 says (in big red letters) NOT to use 5w-30 when driving at high speeds and the ambient temp is over 80F.



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John C
1988 Carerra coupe
1957 Speedster replica
1997 A6 Avant

I've read that if you rebuild and engine and run Mobile 1 synthetic in it from the beginning, it will never break in. With that being the case, you shouldn't initially fill your car with Mobile 1 during the break in period.

Question: If the above is true, why does Porsche fill every car out of the factory with Mobile 1 synthetic? Is it the 15,000 miles oil change interval that makes up for the difference?