Which Oil to Use

[Ken Mikos]

First oil change on my new 1985 3.2 with a Cat Bypass. Thinking about using 20-50Wt Brad Penn. Any other suggestions. Thanks in advance, Ken

[sugarwood]

Mobil 1 15W-50 Synth.
Better in every way than obsolete conventional oil.
If your 911 was built today, Porsche would only suggest Synth.

Forum wanna-be oil experts obsess about a single component for motor oil: ZDDP. The logical fallacy that the forum wanna-bes keep committing is this: they assume that in order to meet the new SM/SN requirements, the ONLY thing the oil companies did was reduce the amount of ZDDP in their oils, leaving everything else unchanged. That's ridiculous. Oil companies have been working on additive packages for decades and testing how well they work in preventing wear. The reduced levels of ZDDP in these oil have been replaced by other, sometimes proprietary, additives that work as well or better. Moot point since Mobil 1 15w-50 has a 1300 ZDDP rating anyway!

And before anyone says it,
No leaks.
Synth leaks are another internet myth.
Debunked.

It's amazing how long misinformation lives on.
People still think carrots are good for the eyes.

It is a wives tale. When synthetics first came out, like 30 years ago, they could affect seals and cause leaks. Oil manufacturers quickly figured that out (they work closely with car manufacturers) and put additives in to stop that.


https://www.walmart.com/ip/Mobil-1-15W-50-Advanced-Full-Synthetic-Motor-Oil-5-qts/20713647

Who runs non-ZDDP fortified Synthetic oil that is not 20w-50?

[HarryD]

Sugarwood has some good points but...

The whole reason the zinc and phosphorus (ZDDP) issue came up was due to engine builders seeing excessive cam failures (mostly on high performance engines) after the oil makers changed to the API CJ4/SJ (and subsequent updates) standards. At that time, ZDDP was reduced to extend catalyst life. This change mostly affected the xW-30 and xW-20 oils but would sometimes also affect the 15W-40 and 20W50 commonly used in our cars.

The reason newer cars can tolerate lower ZDDP levels has to do with the change to the tappet configuration from flat tappets to a roller tappets. This changed occurred in most all new cars in the mid to late -90's as part of the car makers quest for improved gas mileage.

And while the story is more than ZDDP, this is the primary reason for concern. There are many oils that are still ok for our older, flat tappet motors. 15W-50 Mobil 1 is one. Driven GP-1 is another. Most 15W-40 diesel oils are also ok. There are others as well.

Get a good oil made for older cars. As noted above the leaking issue with synthetic oils was an issue many, many years ago but has been resolved.

To add to the confusion, you can get Dino, semi-synthetic, and full synthetic oils. The differences have to do do with whether they use petroleum (dino and semi-synthetic) or synthetic materials for their bases.

I used Brad Penn and it's descendants (PennGrade) until recently with good success. When my motor was disassembled a while back for a top end issue, no excess wear was detected with 150,000+ miles other than the damage due to a backfire. Recently, based on information from LN Engineering and a local well respected engine builder, I switched to Driven GP-1. These guys were my source for the Brad Penn recommendation as well which served me well until now.

But as I tell every one, your car, your money, your choice.

[otto_kretschmer]

look for a 20w50 with a SG or SH rating

mobil 1 Vtwin, Castrol 4t, Redline 20w50 motorcycle oil

[stownsen914]

sugarwood - do you have some evidence that ZDDP isn't actually needed for older, flat tappet type engines?

[GH85Carrera]

Originally Posted by Ken Mikos

First oil change on my new 1985 3.2 with a Cat Bypass. Thinking about using 20-50Wt Brad Penn. Any other suggestions. Thanks in advance, Ken

Perfect choice. That is what I use. It is a semi-synthetic oil and works great.

[darrin]

another happy brad penn customer -- Ken, where do you live? I've been using brad penn's 15w-40 in my Carrera, as the 15w low number provides better low temperature viscosity (which can be useful when I drive/park outside in single digit temperatures) --

[creaturecat]

VR 1 works best in my car. i might be convinced to try the Liquid Moly. tried B P - no like.
no cold outside temps here. heated garage.

[Noah930]

The above recommendations are good: Brad Penn, Valvoline VR1, Driven, Mobil 1 (but only the 15w-50 and V-twin varieties), Royal Purple, etc. Usually we look for 20w-50 weight oils. There are a couple epic threads if you've got lots of time (days) to read them end-to-end.

I think the Mobil 1 15w-50 may be the easiest way to go (though YMMV). It's probably the most readily available/easiest found. Walmart sells 5-quart jugs for about $25 and will ship for free to your front door. But the mechanic that I use sells Brad Penn, so I've used that in the past. When I could find it, I used VR1.

[HarryD]

FWIW, Brad Penn/PennGrade and VR-1 are not what they were a few years ago.

Tech Tuesday: New DRIVEN GP-1 Oils

Brad Penn to Joe Gibbs?

[Noah930]

^^^^ Yeah, that and lack of availability were the reasons I switched to Mobil 1. Plus synthetic is better in a turbo.

[sugarwood]

Originally Posted by stownsen914

sugarwood - do you have some evidence that ZDDP isn't actually needed for older, flat tappet type engines?

Used oil analysis. Test your lower ZDDP oil on your flat tappets. If it wasn't working, it would show up as increased wear metals.

I am not against ZDDP in any way, especially for older cars driven rarely, but people ascribe it these magical properties while ignoring other important aspects of oil. It's a moot point anyway, because I doubt there is an oil that meets the 15W-50 viscosity requirements for the old 911 that is actually low ZDDP.

https://www.amsoil.com/newsstand/classic-and-vintage/articles/reduced-zddp-and-wear-protection/

[Bill Verburg]

Originally Posted by otto_kretschmer

look for a 20w50 with a SG or SH rating

mobil 1 Vtwin, Castrol 4t, Redline 20w50 motorcycle oil

SG hasn't been available since 1993 SH 1996

Current M1 V-twin is SJ and while it is the correct 20w/50 weight has more ZDDP than i desired except for a break in oil, it's P spec is 1750ppm and Zn is 1850
minimmum ZDDP specs for our cars want to be ~1000ppm

M1 Racing 4T 10w/40 is 1200/1300 a very good place to be
M1 turbo Diesel 5w-40 is 1100/1300
M1 truck & SUV 5w-30 is not only too light it's spec is 800/900

Plain ole M1 15w-50 whicch is what I have used for a few decades is 1200/1300

Driven Brad Penn(now called Penngrade 1) also have excellent oils that I've occasionally used

[g911]

+1 on GP-1 for older cars

[HarryD]

Originally Posted by Noah930

^^^^ Yeah, that and lack of availability were the reasons I switched to Mobil 1. Plus synthetic is better in a turbo.

As a historical aside, Synthetic oils were originally invented for turbine service to stop the coking from dino oils at the time..

[Reiver]

Pure virgin Olive oil....with a lemon twist.

Do an internet search and you will have days and days of reading material.

[otto_kretschmer]

Originally Posted by Bill Verburg

SG hasn't been available since 1993 SH 1996

Current M1 V-twin is SJ and while it is the correct 20w/50 weight has more ZDDP than i desired except for a break in oil, it's P spec is 1750ppm and Zn is 1850
minimmum ZDDP specs for our cars want to be ~1000ppm

M1 Racing 4T 10w/40 is 1200/1300 a very good place to be
M1 turbo Diesel 5w-40 is 1100/1300
M1 truck & SUV 5w-30 is not only too light it's spec is 800/900

Plain ole M1 15w-50 whicch is what I have used for a few decades is 1200/1300

Driven Brad Penn(now called Penngrade 1) also have excellent oils that I've occasionally used

eegaad... I had to go back and look at the bottle that I bought a week ago for my R50/5

mobil 1 vtwin is rated SJ but they also say it covers SG and SH

"recommended by ExxonMobil for applications requiring API SH, SG, CF"

https://www.mobil.com/en/lubricants/for-personal-vehicles/our-products/products/mobil-1-v-twin-20w-50/?utm_source=bing&utm_medium=cpc&utm_campaign=PVL_Traffic_Brand_Mobil1_General_Exac t&utm_content=Product_General_V-Twin&utm_term=mobil%201%20v-twin&gclid=b791006165c11a520272606b0a606e93&gclsrc=3p.ds&msclkid=b791006165c11a520272606b0a606e93

and Redline says SJ/SG/SH JASO MA/MA2 for their mc oil

https://www.redlineoil.com/20w50-motorcycle-oil



so I think we officially have an oil thread

edit: take Castrol 4T off my recommendation. Its only SL. You can't go wrong with the other two but you will pay a pretty penny for 12 quarts, especially if you run Redline

[Mutha66]

Motul 4100 15w-50 works great for me.

[Mervo]

Penrite HRP 30 on a 1987 3.2L . Full (1600 ppm) Zinc and doesn't cost the earth.

[TxGerman]

Where does one go to find the Porsche recommended minimum zinc and phosphorus concentrations and oil weight for a modern oil (dino, semi, or full synthetic) in an air cooled classic? With so many opinions, what does the manufacturer (aka implied experts) have to say?