M. Schneider

For your consideration. A week's end oil PPM zinc level fodder.

Bill Verburg

and here is a more comprehensive data set
2017 Mobil 1 products

note that too much can be as bad as too little when it comes to ZDDP/ZTDP, some manufactures are adding Boron to make up for lower ZDDP/ZTDP levels

here's the API oil our cars were designed for back in the '90s
API P Zn B
SJ 1301 1280 151

Best current match from the street M1 products is 15w-50

the racing oils lack the detergent packages needed for extended service intervals, they are generally changed each day or at most week end.

PiB993

I use the V-Twin 20w-50 and it's well accepted here and by my mechanic.

But I did get a little flak from motorcyclists claiming that it had friction modifiers for wet clutches that I may not want in my engine. Considering Motul 300V- 15w-50 but it's approximately 50% more $ than V-Twin.

ETA - Cheapest I found that Motul online with shipping (estimated) is $14.90 per quart for a case of 10 2 liter cans.

Unlike some others I love a good oil thread!

nine9six

I do a 50/50 blend of the M1/V-Twin. The stand alone V-Twin is very, cat killing heavy in ZDDP; even more so than the original formulation of the M1. The blend tames down the ZDDP ppm's of the straight V-Twin while increasing the ZDDP ppm's over the straight M1, and will assuredly extend the life of a cat, while more than sufficiently offering excellent engine protection.

I believe it was CARB that forced the formulation change of the original M1, to lower the ZDDP's in order to extend the life of a cat. And yes, engines cost more than cats, but Im thinking maybe there is a happy medium.

Bill Verburg

It's amazing how often this misinformation gets repeated.

The only mandated reduction on ZDDP was in the API & ILSAC GF4 oils. There was a reduction from the pre-1988 SF levels of ~1500ppm to the 1993 SG ~1200ppm, SH standard in effect for late 964 & 993 production is 1100ppm & 1400ppm. Cam failures became an issue ~2004 when the SM ~800ppm cam out.

Note that only ILSAC GF4 or 5 has the low 800ppm spec(down to 600ppm now), these oils can be identified by the API Starburst label on the can. ILSAC GF4 only applies to the light weight fuel economy oils spec'd for newer cars, ie 0w-20, 5w-20, 0w-30, 5w-30 10w-30 etc.

Non Starburst aka the older donut hole lable oils in the heavier weights have no mandate to reduce ZDDP to the dangerous levels below ~1000ppm. Individual manufacturers have each responded and done there own thing, generally I classify any oil where the spec is not published to be suspect.

To reiterate
heavier, API Donut hole label, 15w-50 & 15w-40 oils may or may not have reduced ZDDP, do your HW to find which ones are in the acceptable range
M1 15w-50 current published spec is 1200ppm P & 1300ppm Zn, right where it was in 1993.

M1 racing 4T 10w-40 is 1100ppm & 1200ppm

M1 V-twin is 1600ppm & 1750ppm this is great for a brake in oil but is approaching dangerously high levels for normal use(long term wear issues set in @ ~2000ppm

M1 0w-40 though not a GF4 or 5 oil has 1000ppm & 1100ppm, Porsche did recommend this oil for many years, though The ZDDP levels are dangerously close to the low end.

nine9six

Bill, thank you kindly for the education!

I wonder why Steve Weiner pumps the Mobil V-Twin oil, while preaching the lowering of ZDDP ppm of the 15/50 Mobil M1?

M. Schneider

+1 .. Thanks B/V

Chapter and Verse -

"here's the API oil our cars were designed for back in the '90s
API P Zn B
SJ 1301 1280 151" end quote.

NYC993

I have done a half dozen of oil tests. My oil analysis showed Zn at 1200 for M1 15-50 and 1500 for 20-50 vtwin. ph is 900 and 1200 respectively.

there was also a noticeable reduction in copper and iron levels as I switched to v-twin.

just sharing my observations...

Mike J

I do not have enough personal oil analysis data to determine which brand and variant is best. I do not care about the cats that much, I have 200 cell sport cats, and if somewhere down the road they fail, so be it.

Like NYC993, all I know is since I bought the Turbo, I have been exclusively using V-twin, and my oil analysis results show much reduced metals in the oil over time, which is exactly what I like to see. The zinc levels at about 1500 at change time. That does not mean that other brands, like Motul, may have produced equivalent or better results - it just means, for my car, using V-Twin has helped to reduce wear metals.

I have no clue if that high of a zn level has long term impacts on my engine, and I suspect since I do not pile on lots of miles, it will be a long time (hopefully) before I need to tear into it - and even then it will be impossible to sort exactly what wear was due to what oil, given the car has had a few owners, and different oils were used through the cars lifetime (like most cars).

You will never get a consensus on this topic, and its hard to sort through all the actual measured facts, opinions, and at times utter BS.

Cheers,

Mikw

Gbos1

How about Porsche Classic 10-60 that was supposed to be designed specifically for our Air Cooled 993s? Any independent tests? ZDDP levels?

Is it just like all the others or is it worth the cost?

M. Schneider

+1 .. Agreed.

However, having changed oil types to Mobil V-twin,, I saved 15 percent on car insurance with Geico. bada bing! Drummer, a rim shot please!

Seriously; For the life of the coupe Mobil 1 synthetic oil has been used. Having started life with a factory Mobil 1 fill, at 11 delivery miles (9/'97) ,, fast forward 2 days at 925 miles for this owner's initial oil change; both filters, I'd drain crank case oil & oil tank. Mobil 1 15w-50 oil was used with continued use for 98% life of the car. Annual OCI or less.
The coupe is driven seasonally in Colorado's high country, elev. 8,200ft (late Spring, Summer and early Fall) logging 3K to 5k miles at best. Present total mileage is in mid-high 80k. Oil usage is within spec, no SAI issues (3 to 4 SAI check valve replacements) The 3.6l runs like new.
The C2S coupe has lived in Germany (autobahn baby) early on in its life and once again more recently .... (Frau's IT engagements)

A few hot, hot CO summers ago with all the discussion of Mobil 1 20w-50 V-twin I'd give it a whirl ... Nothing's changed, the 3.6l runs as new, like a top. Varooom ....

chsu74

Bill has already corrected you.

https://rennlist.com/forums/993-foru...-engine-2.html

Cupcar

Just for the record, I use Joe Gibbs Driven Oil DT-50 oil for air-cooled engines, a 15-50 product. http://www.drivenracingoilsales.com/...synthetic-oil/

Conversation with their tech reveals it is "right at 1300 PPM Zinc" and that it is a pure Group 4 PAO synthetic oil and a mix of PAO and NPAO molecules.

The conversation got interesting when the discussion of Zinc PPM went to the type of detergent package used whether it's Calcium, Sodium or Magnesium based and the molecular weight of the Zinc package used - of which there are at least 42 types available to an oil chemist.

In paraphrase basically the chemist said "Just talking Zinc PPM is not the only issue, you have to put the whole detergent and Zinc package together along with other considerations and a lot of homework went in to making the right formula for DT-50 and it's proprietary".

My race engine builder friend likes Gibbs oil for his Cosworth and other race engines.

So I use it.

Steve Weiner-Rennsport Systems

Thats truly golden advice, right there!!!

This is precisely why I discourage people from jumping from one oil to another to another. Ring sticking is the result and that can lead to excessive oil consumption.

Naturally, this doesn't preclude switching from a product that isn't suited for these air-cooled engines; Mobil 1 0w-40 is one example.

Its always best to choose a good product and then stick with it, regardless whether its a synthetic or not as that serves your best interests over the long term.

The best guidance & advice comes from engine builders who see the innards of said motors and have first-hand results of using such lubricants every day.

DT50 is an excellent product.

bpu699

So, whatever happened to Brad penn? Everyone loved it for air cooled cars and turbos. Now you search for it in google, and it hardly comes up...

Still good? Bad? Some folks were saying it leaves a sludge layer?

Bo