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Hey folks, if you haven't noticed already there are two interesting responses to the classic "what's the best oil for my Porsche?" question that gets asked time and again. Both are found in the Tech Q&A section starting on page 114.
The first Q&A is on the first page regarding best oil for a 2005 911 (yes a very different beast from a 993). The Answer is interesting as it goes into the pros and cons of high ZDDP oils and ultimately is a non-answer to the question. (No surprise really and old news to me based on past Rennlist oil threads.)
The second Q&A is on the last page in the section 121 and caught my eye. The Question is what is the right oil and filter for my "new" '95 993. The Answer states the dealer is wrong to recommend 15w50 oil for a 993 and goes on to state "The 993, 996, Boxster, and all newer models prefer 0w40 to 15w50 because they use oil as a hydraulic fluid to pressurize the lifters.
Now, I definitely has the knee-jerk response to having the 993 lumped in with the water-pumpers oil wise, but I'm intrigued by the explanation about lubricating the lifters as it's new to me. In recent threads, many have complained about the frailty of the lifters used on the 993s.
Is it perhaps a result of using engine oil that is too viscous? Is this risk to the lifters less of a thread than the risk of lower ZDDP oil? Does anyone really have a clue?
Please discuss, but please try to keep it on point here to engine oil impacts on lifters. We have enough rambling oil 1 vs oil 2 comparison threads, that we don't need another.
Well something new in the oil discussion. Is the issue they are bringing to light the idea that the higher viscosity oil will not pressurize the lifters fast enough and possibly cause cam wear during startup?
15w/50 can cause a lifter to hang for a bit on cold starts, you hear a metallic rap until they all pressurize. Mobil 1 5w-40 was the original fill for the Cup cars.
Since I don't drive them when it's cold it's a non issue
I look for zddp and availability M1 15w-50 works fine until I can find a 5w-40 w/ adequate zddp
Because of threads like this and on Pelican, I recently opted for 20w-50 dino oil. Now it appears that was not the right decision and I should have gone with the cheapo 0w-40 from Walmart?
Because of threads like this and on Pelican, I recently opted for 20w-50 dino oil. Now it appears that was not the right decision and I should have gone with the cheapo 0w-40 from Walmart?
No, first most 0w-40 isn't el cheapo, second all the 0w40 i've seen is low zddp
I have a case of M1 0w-40 left from the last Audi I had, it was great oil for that car but I only use it mixed 6:1 w/ 5w-30 in my Toyota and never in the 911 or 993
Hi Bill, since I purchased my 993 I have also looked for a 5W40 with adequate ZDDP for our engines. I have only been able to come up with Diesel oil formulations ie: Mobil 1 5W40 diesel, Rotella T6 5W40 and even Joe Gibbs DT40 5W40 Diesel.
If you could still find the old CI4+ spec on shelves I wouldn't hesitate to use it but the CJ4 spec reformulation back a few years ago keeps me from using it in my 95 C2.
Here is the Mobil 1 chart, seems there are several offerings with relatively high ZDDP >1000 and various viscosity ranges depending on temperature ranges where one lives. It is interesting the 0w50 looks to be a racing oil with very high ZDDP and is not recommended for street cars probably because it kills catalytic converters.
Shell Rotella T6 is a synthetic 5w40 oil formulated for Diesel and its got over 1200ppm ZDDP... and apparently the only reason it's not recommended for gasoline engines is due to the zinc content and its affect on Cats. Tons of ppl running it in gas engines. $6/qt is par for the course.
Here is the Mobil 1 chart, seems there are several offerings with relatively high ZDDP >1000 and various viscosity ranges depending on temperature ranges where one lives. It is interesting the 0w50 looks to be a racing oil with very high ZDDP and is not recommended for street cars probably because it kills catalytic converters.
Andy :-)
My research suggests that ZDDP closer to 1300 is better. Hence I went with Valvoline VR1 20w-50.
[QUOTE=RichPugh;12061961]Shell Rotella T6 is a synthetic 5w40 oil formulated for Diesel and its got over 1200ppm ZDDP... and apparently the only reason it's not recommended for gasoline engines is due to the zinc content and its affect on Cats. Tons of ppl running it in gas engines. $6/qt is par for the course.
In researching the use of this for my audi, which beats the crap out of oil due to DI. I've come across some discussions that diesel oil, may or may not have the anti foaming package added since they don't tend to have high revs compared gasoline engines. Be that as it may, Pano screwed the pooch with their comment, in my opinion.
Origin is most possible Exxon as the OEM oil supplier for Porsche ...
dont forget: none of the Porsche (in the manual) recommended oils for our cars is available anymore today; even with similar labeling, the content changed a lot.
02-22-2015, 04:55 PM
Feb '15 Pano - Two interesting 993 oil comments
