10W60 in Aircooled Porsches

[WP0ZZZ]

Today, Porsche released a video starring 5 great aircooled cars from the Porsche museum. When showing the 908/03 Spyder, I noticed that it had a label on the oil tank cap that said 10W60. Incidentally, this is the oil viscosity that Porsche currently recommends for the late aircooled road cars. Any thoughts on this?




The video (minute 4:51):
https://www.youtube.com/watch?v=0UHUKh_oOWI

[MARISOL78sc]

Same oil I use in my e46 M3, Castrol....not sure of the Porsche application-always 20-50 Brad Penn in the SC different animal the 908

[Canada Kev]

I don't imagine they used 10w60 back in the day. I doubt multi-viscosity oils of that large of range were even invented at that time.

[WP0ZZZ]

Originally Posted by Canada Kev

I don't imagine they used 10w60 back in the day. I doubt multi-viscosity oils of that large of range were even invented at that time.

I agree, but this is a 908 that is currently run by the Porsche Museum and I found it interesting that they use the same oil viscosity as Porsche currently recommends for the latest roadgoing aircooled 911s (78-98).

I believe that not many people uses 10W60 on aircooleds and that's why I wanted to know your opinions.

[GeorgeK]

I have used Castrol 10W60 in my 964 from 210K Kms to 265 K Kms, time of a top end rebuild.
No discernable wear on the camshafts, rockers, pistons or cylinders.

[Sunroof]

I have been using Valvoline 20W-50W VR oil for decades in my 944, 911's (1973.5T, 1974 - 911 and 1979 911SC). I have had no issues with this oil over the past 30 years.

[Autoban]

Where do you even find 20W50 these days? I can't find it at our local Auto parts stores. The best I could find is Mobile 1 0W40.

Juergen

[Raceboy]

Oil choice for precious 911 engine that needs high ZDDP and very good oil since it solely relies on oil? Motul 300V 20W-60 Le Mans obviously.

[Tippy]

Originally Posted by Raceboy

Oil choice for precious 911 engine that needs high ZDDP and very good oil since it solely relies on oil? Motul 300V 20W-60 Le Mans obviously.

I'm not using any oil that they can't spell '24 hours of Le Mans' right!

Just kidding, Googling now. Like to try it.

[Bill Verburg]

Originally Posted by Autoban

Where do you even find 20W50 these days? I can't find it at our local Auto parts stores. The best I could find is Mobile 1 0W40.

Juergen

M1 0w40 comes in several formulations
Here are the latest 2018
M1 FS 0w-40 is at the very lower limit of ZDDP needed in the older air cooled cars, this is the latest formulation of the oil Porsche has been recommending for the last 10 yrs or so for air cooled cars.

M1 ESP 0w-40 is a little bit below the lower limit of ZDDP needed in the older air cooled cars,

M1 15w-50 has the correct amount, I buy it at Walmarts in 5 gallon jugs, It's funny that of the 2 closest stores one carries it and the other doesnt'

M1 20w-50 v twin has more ZDP than is necessary, its formulated for applications where a wet clutch is used.

from the Brookstone assays of Porsche 10w/60 that I've seen P is a tad low and Zn is at the lower limit

VR1 from Brookstone asays is low in P( but that's ok as it's not the active ingredient) and has good Zn, the Zn is important as it is the active ingredient.

There are several other good oils that aren't generally available locally , for these you'd have to do mail order
Gibbs
Brad Penn
Penngrade

[1979-930]

Motorcycle shops carry the heavier weight and wide spread multi weight oils.
We have a Cycle Gear near me and the cashiers always have a comment when I buy there entire stock of Motul 10/50 once a year.
I don't think I have seen the 10/60 in stock.

[Jeff NJ]

Bill, regarding the 20w-50 v twin oil, is more zddp than necessary a bad thing, or do you mean that once over a certain level, it doesn't help any more?

[Bill Verburg]

Originally Posted by Jeff NJ

Bill, regarding the 20w-50 v twin oil, is more zddp than necessary a bad thing, or do you mean that once over a certain level, it doesn't help any more?

yes, more is bad at some point, according to industry testing levels of Zn above 1400ppm increase wear.

Typically break in is where you want increased wear to occur, break in oils want > 1400, they are usually in the 1600 to 2000 range. These are used for a very short time and then replaced by oil designed for longer term use.

Zn is the active ingredient, it's anti-wear properties are activated by heat and pressure and the Zn is lost to atmosphere in the process, ZDDP is a molecule which contains Zn and P, High P levels are what over time poison catalytic converters. Modern Starburst oils have all have greatly reduced ZDDP to keep P out of the exhaust. Non Starburst oils like racing oils and severe duty oil such as M1 15w-50, Joe Gibbs, Brad Penn, Penngrade et al have 1100 -1300ppi ZDDP. Which is what you want.