Do you run Synthetic oil or Mineral oil?

[Maxx1]

I know the advantages of synthetic but I'm not too keen on switching over... my 100K 87 911 started leaking like crazy (cold temps) when I switched over.

The other thing is, I only drive my 930 about 1,000 miles a year if even that.


What do you use and why?

[Tippy]

Valvoline VR1 but no catalytic converter.

[speed964]

I have an 87 930, after I purchased the car I had all fluids replaced and I opted for synthetic oil. Before switching to I had a very slight leak ... its was more like a dampness that i would notice in certain areas. after I switched the to synthetic oil ... it was a leak. So from my experience I would use went fossil oil.

ps I only drive my car about 2k per year

[gsxrken]

Synthetic.
Dino in the trans box, though.

[JFairman]

Valvoline VR1 20w50 synthetic.

It's supposed to good stuff and it should be since it cost twice as much as the non synthetic VR1.
I got a bunch when it was on sale 50% off a while back.

[timc]

AMSOIL for the last 100K miles. Engine never been apart.

[ficke]

I use Total 5W-50W synthetic oil.
On dry sump and large volume oil reservoir cars I would only use synthetic oil, it flows well even in cold weather. Warm up time for good oil flow is a lot less and since these cars hold a lot of oil it takes a long time to get oil up to temperature for flowing well. I will put up with any leak issue for the good cold weather oil flow of synthetic. There are other advantages of synthetic oil but not near as obvious.

[guru944]

maxx1;

Go for AMSOIL 100% Synthetic PAO 10w-40 AMOQT or 5w-40 European AFL QT
Follow these Basic Guidelines
-4 To 95 F......10W-40, 10W-50
-13 To 68 F......10W-30
-22 To 32 F......5W-30
Above 14 F......20W-50
Above 5 F......15W-40, 15W-50
Below 14 F......5W-20

timc, I'm there with you brother....

You can purchase this oil directly through my E-store site Blackbird Temp 1
PM me if you have more questions for me....
Go for it!

[twin plugged targa]

I thought the total oil capacity was not used until the engine got to operating temp and then a valve opened to use remaining oil and oil cooler?
Please correct me if wrong thanks - ps I use Dino oils as I do not run the car hard or track it.

[ficke]

Originally Posted by twin plugged targa

I thought the total oil capacity was not used until the engine got to operating temp and then a valve opened to use remaining oil and oil cooler?
Please correct me if wrong thanks - ps I use Dino oils as I do not run the car hard or track it.

On a conventional v-8 engine like Chevy, ford, etc. have made, oil is pumped to the top of the engine and takes a vertical path down to the sump where it is pumped back up, these engines only hold a relatively small amount of oil ,5 quarts, and it heats up quickly and flows well and since it takes a vertical path to the sump and these engine are not ran at high RPM's oil starvation is not likely. Same thing for the common in line 4 as used in so many imports.
You are some what correct with your statement. oil will not go through the coolers till at operating temperature. But..
All 911/930 are 'dry sump' engines what that means is oil is pumped out of the oil tank to pressurize the engine and lubricate and cool parts then has to flow on a horizontal path back to the engine sump where it is pumped back to the tank with another oil pump next to the first one that is used for this scavenger purpose. Since we 911/930 owners have at least 12 quarts of oil to heat up and with that horizontal path some of the oil has to flow, couple that with the fact our engines need some RPM's to make power and maybe a slightly impatient driver on a cold morning, can = oil starvation. Synthetic oil is a way to help over come this cold weather situation for 911/930's.

[cajun]

I still run fossils in my 930. Everyone I spoke with informed me the synthetic causes leaks...

I don't drive my car much since my kid came along...

[ficke]

Synthetic oil does not make leaks, it can make leaks more obvious. So it is harder to mask and hide a leaky engine with synthetic oil.
Just to use a little deductive logic, If synthetic oil caused leaks then all new Porsches would be leaking from the factor installed synthetic oil.

[Fast82930]

I've been running Brad-Penn 20/50 for several years now in my 930, also run it in my 944 racer.

[DohertyCM]

Synthetic doesn't cause leaks...

Synthetic oil is oil where all of the molecules of oil are the same size, unlike dino oil where there are multiple sizes... synthetic is small...dino is small medium and large.

The newer engines are built to a finer tolerance so the synthetic oil is used to get to all the small places. The oil leaks people experience are those fine molecules of oil finding the small areas that are not machined as well. SOME gaskets don't care for synthetic oil...I don't remember why to be honest...I would have to go read again...but the main thing is machining on the engine itself. There are other desirable things about synthetic, but I am only addressing the leaking thing.
Nothing wrong with dino oil, and there are some really good ones out there. AND THERE ARE MANY GOOD THREADS on this board that cover discussions on oil...so I don't want to rehash that.. including the additives you can use.. But if it leaks with synthetic, then just switch back to dino oil. When or if the engine is rebuilt, make sure they ensure all of the surfaces are clean and FLAT prior to putting it back together. And then try using synthetic again.

[guru944]

Tech info to share:

Di-Ester oils: Type 5 -Mix of alcohols and acid composition. Redline, Motul, Lucas etc. Used in Racing....Short term, high stress, Short storage and usage life, component seperation after initial use.

PAO Oils: Type 4 Poly-alpha-olifins 100% Laboratory formulation. Recommend AMSOIL Original stuff and more stable 2-3 yrs typical.

Hydrocracked Mineral "Dino" Oils & Parafins, Type 3, "Fully Synthetic" and Blended: Mobil-1, Castrol GTX, Kendall, "Fully synthetic" Greater than 20% Synthesized Polymer additives...

Choose your "Poison"
AMSOIL Saved 1 of my race Engines and my Turbo sports Car.
Proven and Industry Technology Leader....

Interested visit: AMSOIL Shop by Product

PM me for any Technical application questions.

Blessings..."Walk in the Light"

[JFairman]

I've always heard great things about Amsoil synthetic oil.

And fwiw from what I've seen and some other people have seen brad pen is the worst oil you can use in a turbo motor. I've never seen as much carbon film, sludge, and coke deposits in in a turbo motor from any oil as much as from using that stuff.
Maybe it's ok in a normally aspirated motor that does not have the intense heat of a turbocharger to deal with... as long as it's changed every 3000 miles.

[911nut]

Used to use Brad Penn until I saw all the coke in my engine. Now I use Mobil 1 V-Twin.

[timc]

Originally Posted by cajun

I still run fossils in my 930. Everyone I spoke with informed me the synthetic causes leaks...

I don't drive my car much since my kid came along...

130K miles, 100K using AMSOIL, NO LEAKS, well let's say nothing hits the floor. I am sure I have weeps in a few places, but my floor is bone dry under the car. I run 20/50 year round.

[930cabman]

Castrol, either 5w-20 or even 20w50 depending. I have never had an engine fail in 40+ years ......

Back in the '70s I tried the first Mobil 1 and was not convinced by the claims or the price.

I do run "Motorcraft" Synthetic blend in our 2012 F150 Ecoboost.

[j930]

valvloine vr1 racing oil for my 84 , with how often i change it I'm not sure of the benefit of synthetic and yes i have heard of leaks being a issue