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Inconsistancy in Porsche Oil Viscosity Recomendations, what's up?
Below is what it says in my owner's manual and what Porsche says in their Classic Motor Oil brand marketing page online, what gives?
My view is that if the oil pressure gauge at idle sits below 2 bar in the climate where ones lives one should consider a heavier weight oil at their next oil change. Does this seem reasonable?
Porsche just wants everyone to buy their overpriced oil
HI SDM,
Yes, I understand this but when the owner's manual suggests a 40 weight oil and Porsche Classic Brand recommends a 60 weight oil it seems a rather large spread for both to be suitable for the same application. Especially since the Mobil 1 brand recommends a 40 weight oil.
Andy
And the oil weight range(s) specified in the owners manual will also vary by country... 25 years ago when they were published, they were meant as a guide and not a hard/fast rule. The approved oil TSBs have always superseded anything in printed form from Porsche. ex. PAG pulled the general GL5 classification for gearbox oil (that is specified in your owner's manual) back at the end of production of the 993. Back in the day, they even put out warnings about using any oils in the USA that were manufactured from Pennsylvania base stock because of coking issues discovered during long term durability testing of air cooled engines.
Last edited by JasonAndreas; 08-25-2021 at 01:57 PM.
I went ahead and asked for some guidance from both Porsche & the Mobil 1 Brand folks:
---------- Original Message ----------
From: "andrew.hess@differentlight.biz" <andrew.d.hess@comcast.net>
To: "info@porschedrive.us" <info@porschedrive.us>
Date: 08/25/2021 2:46 PM
Subject: Porsche Oil Recommendation discrepancy
Dear Porsche USA,
It seems that we are getting conflicting information from you as to what viscosities of oil are best for our 993 air-cooled cars.
On your website, your Classic branded oil and Mobil 1 brand as your go-to oils however these two sources recommend significantly differing viscosities oils as fills for these cars, Classic 10W-60 vs Mobil 1 FS 0W-40. https://www.porsche.com/usa/accessor...rts/engineoil/
Also in the case of your Classic branded oil, there is no mention of at what ambient operating temperatures it should be used a significant omission. I have been in contact with the Mobil 1 folks, see the below reply.
Please read the below Rennlist posting and reply with your guidance: https://rennlist.com/forums/993-foru...what-s-up.html
Best regards,
Andrew Hess
3410 Ridgemere Drive,
Henrico, VA 23233
804.252.3193
---------- Original Message ----------
From: Mobil Products <mobilproducts@ourdataworks.com>
To: andrew.hess@differentlight.biz
Date: 08/25/2021 12:25 PM
Subject: Re: Technical Variation Contact Us
Andrew,
Thanks for writing to us. We are always going to defer to the judgement of the engine designer(s). They know better than anyone what a specific engine needs based on construction, materials, and tuning. If Porsche AG (not just some dealer) is calling for 10W-60 in your model, that's a pretty significant deviation from 5W-30 on the low end. It sounds like the kind of thing they would likely have detailed in writing via a technical service bulletin, and having it in writing should provide both insight and peace of mind.
Our data by year, make, model, and engine comes to us from MOTOR Information Systems, a division of Hearst Publishing. The staff at MOTOR collect data from auto manufacturers for resale to the automotive aftermarket. If you can share something in writing from Porsche that supports a change, I'll be happy to pass it along to see what we can do about an adjustment. My most current data, however, says you don't need an SAE grade ending in anything higher than 40.
Thank you for choosing Mobil,
Jim
Mobil Help Desk Team Lead
If I can help further with this inquiry or with any other questions, please respond to this email or phone us 1-800-ASK-Mobil
If you would like to provide feedback on your experience with us today, please email feedback@ourserviceworks.com
On Wed, 25 Aug at 9:21 AM , Andrew.hess <andrew.hess@differentlight.biz> wrote:
Form Data
First Name: Andrew
Last Name: Hess
Company: DIfferentlight
Email address: andrew.hess@differentlight.biz
Phone Number: 8042523193
Question: My 1996 Carrera owner's manual recommends viscosities of 5W-30 to 10W-50 based on environmental temps. Porsche now suggests 10W-60 oil in their below Classic Branded oil page for 911 with > 3,0 Liter air-cooled engines, my 1996 has such an engine. My view is that your Mobil 1 FS 0W-40 is the oil to use and if the idle pressure on the oil pressure gauge falls below 2 Bar on a regular basis one should switch to Mobil 1 FS-X2 5W-50 weight oil. Is this reasonable? Thanks, Andy
I hate beating a dead horse but the # 1 change in oils from circe 1995 to today is the US governments interference in influencing the reduction of ZDDP for new car use, they have also had their finger on weights via the CAFE fuel economy standards promting a move to generally lighter weight oils
0W-40 and 5W-40 synthetics all over that 1996 TSB from Porsche. According to the chart on the first page (far right), they are perfectly fine between -20*F through 120*F+
If we’re supposed to use Mobil 1, why did my car come with a Shell oil sticker in the engine bay?
Nobody is telling you to use Mobil 1
choose the weight that is appropriate for your use
check the ZDDP levels remember that this is where the oils have changed from 1995 to 2021
enjoy
I would love to use a 15w-40 or maybe even a 0w-40 oil, however none of the readily available to me, around here oils fit that bill, M1 FS & FS X2 0w-40 is close but the ZDDP level is uncomfortably low @1000ppm P & 1100ppm Zn
remember that the SE oils available in 1996 had 1300ppm ZDDP, this is not necessarily the case w/ the current SN oils
back in '95 API SE M! 15w-50 had 1200ppm P & 1300ppm Zn and funny thing the current M!15w-50 though API SN is the same. That's why I use it, Everyone else needs to make their own decision
Additionally I think that Porsche has their own commercial reasons for recommending first in the early 2000s M1 0w-40 and now their so called classic 10w-60
through the 964s Porsche had a marketing agreement w/ Shell, they changed to Mobil, now who knows where their oil comes from as they do not publish the specs that I'd like to see.
0W-40 and 5W-40 synthetics all over that 1996 TSB from Porsche. According to the chart on the first page (far right), they are perfectly fine between -20*F through 120*F+
Minds are melting.
Yeah but try to find one that's readily available and has SE levels of ZDDP
choose the weight that is appropriate for your use
check the ZDDP levels remember that this is where the oils have changed from 1995 to 2021
enjoy
I would love to use a 15w-40 or maybe even a 0w-40 oil, however none of the readily available to me, around here oils fit that bill, M1 FS & FS X2 0w-40 is close but the ZDDP level is uncomfortably low @1000ppm P & 1100ppm Zn
remember that the SE oils available in 1996 had 1300ppm ZDDP, this is not necessarily the case w/ the current SN oils
back in '95 API SE M! 15w-50 had 1200ppm P & 1300ppm Zn and funny thing the current M!15w-50 though API SN is the same. That's why I use it, Everyone else needs to make their own decision
Additionally I think that Porsche has their own commercial reasons for recommending first in the early 2000s M1 0w-40 and now their so called classic 10w-60
through the 964s Porsche had a marketing agreement w/ Shell, they changed to Mobil, now who knows where their oil comes from as they do not publish the specs that I'd like to see.
Yeah I had Liqui Moly 5w40, but my local shop, Mayo Performance, said it didn’t have enough ZDDP. They put in “Valvoline Racing Oil 20w50.”
I know the Shell/Mobil 1 stickers were just marketing agreements. I was just teasing.
The oil is determined by the bearing clearances, operating temperatures, and type of driving. Many people make the mistake of running too thick of an oil given the bearing clearances and temperatures and that can have negative consequences just as much as too thin an oil.
Add to that how old these engines are now mileage-wise and there isn't exactly a one size fits all anymore. Anyone with a rebuilt bottom end surely has a copy of their blueprint sheet and recommendations from the engine builder so that's another story.
As mentioned, if you need to wing it, go by what the car is telling you such as the oil pressure gauge. Make sure your pressure is not too high for too long on cold start and not too low at full temp.
Personally, and I think most would agree, if you are in the moderate to high-temperature parts of the US and running a Group V ester oil (Redline, Motul, etc.), 10W-40 for street and 15W-50 if you do DEs works well as a general rule of thumb on stock bottom ends. - If you live in a cold climate and drive year-round, you should of course be running a winter weight vs a summer weight oil.
Last edited by anguilla1980; 08-25-2021 at 07:43 PM.
08-25-2021, 11:02 AM
Inconsistancy in Porsche Oil Viscosity Recomendations, what's up?
