Porsche factory now recommends 0w40 but most independents say 15w50. Concerned about low ZDDP in 0w40. Heard that new silver top 15W50 has higher levels. 15w50 was the approved oil back when my '95 Carrera was "born". Have been told that 0w40 is better for hyd lifters but I think its to lower emissions and better CAFE. Opinions, please?
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MOBIL1 0W40 or 15W50 for Porsche 993?
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I have a watercooled Porsche so I can only speak for 996/86 and 997/87 engines, but I know that for the early watercools the 15w50 was the recommended fill until 0w40 came out and was easily obtained in the U.S. With the watercooled engines, generally unless you live in a very warm climate with mild winters or do not drive your car in the winter, the 15w50's are a definite no no. Also, even in warm climates a Porsche TSB claimed that the variocam (I believe) mechanisms were not adequately lubricated until the oil engine warmed up with the 15w50's. Scope out more over on renntech if you are not already there.
If you want to best of both worlds, you can try to get your hands on the new Q Horsepower 5w50. It is an approved fill for Ferrari, but is very difficult to find, although supposedly a very good oil. Hope that I have been of some help.
If you want to best of both worlds, you can try to get your hands on the new Q Horsepower 5w50. It is an approved fill for Ferrari, but is very difficult to find, although supposedly a very good oil. Hope that I have been of some help.
If you struggle to come to a decision, you could always settle on mixing the two oils. M1 0W-40 has a higher than average ZDDP level for API SM oils and has quite a bit of boron and some moly (soluble type), so it's not weak additive-wise. I think the new M1 15W-50 does have slightly higher ZDDP level (based on what Mobil said) but have not seen a VOA or UOA of it yet.
M1 10W-40 High Mileage is looking strong so far and is a middle ground viscosity that may suit your engine well.
M1 10W-40 High Mileage is looking strong so far and is a middle ground viscosity that may suit your engine well.
all the 993 and older air-cooled engines uses 15W-50
since the water-cooled 996/boxter/cayenne/carerra GT all uses 0W-40
that's what the porsche dealership uses, don't put 0W-40 in ur 993 coz they will burn oil like crazy
since the water-cooled 996/boxter/cayenne/carerra GT all uses 0W-40
that's what the porsche dealership uses, don't put 0W-40 in ur 993 coz they will burn oil like crazy
I have a '85 911 with 184K miles. I have been on a mission for over one year to find replacement for the GTX 20W50 I have used for ~158K miles. It will take another year or more but right now QS Q-Torque synth 10W40 is in and looking really good.
After running 20W50 and this mileage I expected oil consumption to go higher, like....drip out the tailpipe. It was consuming +1qt/600 miles like Porsche said.
Oil consumption may have decreased with 10W40 and the engine did not blow-up !!! I looked at my owners manual and I can even use 5W20 in a +20year old car.
It's hard not to stay on the _W50 bandwagon but better results are better results. I'm not there yet but _W50 class oil may be wrong.
M1 0W40 Euro...I would use that. It's the most spec'd oil in the world. But 15W50 has nothing to do with the 0W40, it's in a different class IMO. I have PP 15W50 on deck for next summer but right now 10W40 is it.
After running 20W50 and this mileage I expected oil consumption to go higher, like....drip out the tailpipe. It was consuming +1qt/600 miles like Porsche said.
Oil consumption may have decreased with 10W40 and the engine did not blow-up !!! I looked at my owners manual and I can even use 5W20 in a +20year old car.
It's hard not to stay on the _W50 bandwagon but better results are better results. I'm not there yet but _W50 class oil may be wrong.
M1 0W40 Euro...I would use that. It's the most spec'd oil in the world. But 15W50 has nothing to do with the 0W40, it's in a different class IMO. I have PP 15W50 on deck for next summer but right now 10W40 is it.
If you were closer, I have a case of the SL rated 'RED cap' Mobil 1 that I would sell you cheap.
I am glad that people with more aircooled knowledge than me spoke up and shared their expertise. Best wishes to you and your P-car.
A lot of the PCA members here in SoCal use 15w-50 M1 or 10w-60 LubroMoly Racing oil, due to the temperature and use (Buttonwillow and Willow Springs can be over 120-deg ambient air temp!) in their aircooled cars. Most of the independent Porsche shops here also use heavier weights. It's too bad that the old red-cap M1 is tough to find, but there are other options...Motul 300V, LubroMoly, RedLine, etc.
New to the site, 1st post. I joined because I too have an air/oil cooled (90 911 C2) and was concerned about what's happening to oils. However, I feel better about the new M1 15W50 since over on the VOA forum, the SM oil's numbers look really close to the old SL numbers. Based on that I think I'm sticking with M1, regardless whether it's Group III or IV.
Hi,
The Porsche TISBs are applicable back to MY84 and viable for 993 engines
The factory uses 15w-40 mineral lubricants in its own early aircooled engines and 20w-50 mineral lubricants (warmed up to 80C before revs or load is applied) in its older race engines
For a 993 the 5w cold start rating is important IMO and a SAE50 mineral lubricant without it is probably undesirable. The Brand is largely irrelevant!
A 5w-40 viscosity "mixed fleet" synthetic HDEO is a viable non Approved lubricant for a 993
tilley - M1 is a PAO product - the exceptions are M1 0w-40 and M1 TDT 5w-40 (aka Delvac 1 5w-40) which are both Group 4/5
The Porsche TISBs are applicable back to MY84 and viable for 993 engines
The factory uses 15w-40 mineral lubricants in its own early aircooled engines and 20w-50 mineral lubricants (warmed up to 80C before revs or load is applied) in its older race engines
For a 993 the 5w cold start rating is important IMO and a SAE50 mineral lubricant without it is probably undesirable. The Brand is largely irrelevant!
A 5w-40 viscosity "mixed fleet" synthetic HDEO is a viable non Approved lubricant for a 993
tilley - M1 is a PAO product - the exceptions are M1 0w-40 and M1 TDT 5w-40 (aka Delvac 1 5w-40) which are both Group 4/5
I'd try either of these in the air cooled 993.
http://www.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_Motorcycle_Oils.asp#ApplicationsTitle
Going to have plenty of ZDDP and is approved for autos. Flash point is excellent.
http://www.mobil.com/USA-English/Lubes/PDS/NAUSENPVLMOMobil1_Motorcycle_Oils.asp#ApplicationsTitle
Going to have plenty of ZDDP and is approved for autos. Flash point is excellent.
Imo, Mobil 1 10w-40 Hi-Miles is the pick. SL additive levels and apparently a excellent base with high HT/HS.
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I`ve been using M1 silver cap 15W50 since it came out (I used the Extended Performance 15W50 for about 2 years prior) and I`ve been really happy with it. I can kick my Z up to redline and it`s completely smooth and quiet. I`ve thought about going to a thinner oil (M1 10W40 HM) but I`ll probably stick with the 15W50.
Thanks Doug. I'm only the 'new' owner of my 90 911, but going through the service records, it looks like it was always run on 20W50, 15W50 and 15W40.
I'm concerned that going to anything with a 5W (or 10W) might start causing leaks to appear. The car is currently leakless, a rarity among the 964 model 911.
I have seen a 1992 Porsche Tech Bulletin that indicates a 15W50 mineral oil would be OK down to -20 deg C or so. If this was good back then, why not now? And even more so with a synthetic?
I'm concerned that going to anything with a 5W (or 10W) might start causing leaks to appear. The car is currently leakless, a rarity among the 964 model 911.
I have seen a 1992 Porsche Tech Bulletin that indicates a 15W50 mineral oil would be OK down to -20 deg C or so. If this was good back then, why not now? And even more so with a synthetic?
Hi,
tilley - In any event it is always a personal choice. It is your car after all
If the car has always been on the three lubricants you mention I would consider living with one of those - a 15w-40 mixed fleet HDEO being a good safe pick. The only SAE50 lubricant that is Porsche Approved for the 993 is M1 5w-50. This is available in Canada and is perhaps your best choice if moving to a synthetic
The progressive TSIBs overwhelm the Drivers Handbook and all earlier TISBs. These are based on end user and Dealer feedback along with Factory Warranty experience. A 1992 TSIB is now quite meaningless due to advancements in lubricant techonology and the likes
tilley - In any event it is always a personal choice. It is your car after all
If the car has always been on the three lubricants you mention I would consider living with one of those - a 15w-40 mixed fleet HDEO being a good safe pick. The only SAE50 lubricant that is Porsche Approved for the 993 is M1 5w-50. This is available in Canada and is perhaps your best choice if moving to a synthetic
The progressive TSIBs overwhelm the Drivers Handbook and all earlier TISBs. These are based on end user and Dealer feedback along with Factory Warranty experience. A 1992 TSIB is now quite meaningless due to advancements in lubricant techonology and the likes
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Doug,
Excuse me if my next question makes me sound tribologically ignorant, but why if a 15W50 was good back in 1990 (per the Owner's Manual), is it not recommended any longer? Isn't viscosity, viscosity? If 0W40 and 5W40 (and one 5W50) is what Porsche now recommends, and nothing else, why don't they contact all Porsche owners (especially the non-forum browsing types) and let them know of these important changes to their Owner's Manual? Their TSBs are hard to come by for the average driver, so most owners would just continue to follow their Owner's Manual (unless of course they still go to their dealer for oil changes).
[Also, as far as I know, the car has been run on synthetic since early in it's life, and currently has a 20W50 synthetic in it. I have read/heard of air/oil cooled owners switching to the new 0W and 5W and leaks forming where there were none before...hence my hesitation to switch to anything lower than a 15W]
And thanks for everyone's feedback.
Excuse me if my next question makes me sound tribologically ignorant, but why if a 15W50 was good back in 1990 (per the Owner's Manual), is it not recommended any longer? Isn't viscosity, viscosity? If 0W40 and 5W40 (and one 5W50) is what Porsche now recommends, and nothing else, why don't they contact all Porsche owners (especially the non-forum browsing types) and let them know of these important changes to their Owner's Manual? Their TSBs are hard to come by for the average driver, so most owners would just continue to follow their Owner's Manual (unless of course they still go to their dealer for oil changes).
[Also, as far as I know, the car has been run on synthetic since early in it's life, and currently has a 20W50 synthetic in it. I have read/heard of air/oil cooled owners switching to the new 0W and 5W and leaks forming where there were none before...hence my hesitation to switch to anything lower than a 15W]
And thanks for everyone's feedback.
Hi,
tilley - A Driver's Handbook is a "Sales" document and is a general statement in time. It shows what can be used for a vehicle marketed Internationally (usually) and where perhaps only a limited number of viscosities are available
TISBs are the products of experience and are issued by the manufacturer's Service Engineers. With German vehicles at least it has been this way for over fifty years that I know of and have been directly involved with
For instance since 1990 no SAE30 lubricants of any type have been Approved by Porsche. This is due to a lack of a suitable HTHS viscosity during extended test ACEA protocols. Such a lubricant will be in your Handbook however and I am sure no thinking (Porsche) person would use such a lubricant unless it was the only one available and needed for some dire reason
As an example a recent survey of lubricants for Porsche 928 V8 engines showed some disparity between Handbooks, Service Information Books and Technical Information Service Bulletins (TISBs). It showed that from 1984 until the end of production in 1995 Porsche moved via TISBs from Listing any 15w-50 or 20w-50 lubricants to 5w-40 and 0w-40 (and Mobil 1 5w-50, the only Approved SAE50 lubricant) meeting at least ACEA A3/B3 specifications
There is a good reason for this as these 32V engines have hydraulic lifter/adjusters and a need for at least a 3.5cP HTHS vis. They have a relief valve setting at around 8-9bar too!
As well it is known that an independent Porsche Service point in Sydney Australia used an unsuitable 25w-50 mineral ACEA A2 (and TBN 8) lubricant in these engines at this time. This is quite common practice when outside the Manufacturer's loop - I have seen this many times before and ultimately to the vehicle owner's detriment
It is well know that for the same reasons (valve actuating technology) the M96 engines are almost universally on a 0w-40 lubricant and with now many years of user and Warranty experience. No mineral lubricants have been Approved by Porsche since MY1999 yet my MY2001 Handbook lists a mineral 20w-50 lubricant option!
Porsche TISBs for non Cayenne V6 (VW) engines show around 30% are 0w-40 viscosity, 70% are 5w-40 viscosity with M1 5w-50 being the sole SAE50 lubricant Listed. And believe it or not M1 5w-50 is quite a different "animal" to M1 15w-50 from a "flow" perspective
Why doesn't Porsche advise Owners? - well they do via their Dealerships. In their Handbooks of recent years they also say "use only a Porsche Approved lubricant" or as such
glennc - Of course I totally agree with your comments
tilley - A Driver's Handbook is a "Sales" document and is a general statement in time. It shows what can be used for a vehicle marketed Internationally (usually) and where perhaps only a limited number of viscosities are available
TISBs are the products of experience and are issued by the manufacturer's Service Engineers. With German vehicles at least it has been this way for over fifty years that I know of and have been directly involved with
For instance since 1990 no SAE30 lubricants of any type have been Approved by Porsche. This is due to a lack of a suitable HTHS viscosity during extended test ACEA protocols. Such a lubricant will be in your Handbook however and I am sure no thinking (Porsche) person would use such a lubricant unless it was the only one available and needed for some dire reason
As an example a recent survey of lubricants for Porsche 928 V8 engines showed some disparity between Handbooks, Service Information Books and Technical Information Service Bulletins (TISBs). It showed that from 1984 until the end of production in 1995 Porsche moved via TISBs from Listing any 15w-50 or 20w-50 lubricants to 5w-40 and 0w-40 (and Mobil 1 5w-50, the only Approved SAE50 lubricant) meeting at least ACEA A3/B3 specifications
There is a good reason for this as these 32V engines have hydraulic lifter/adjusters and a need for at least a 3.5cP HTHS vis. They have a relief valve setting at around 8-9bar too!
As well it is known that an independent Porsche Service point in Sydney Australia used an unsuitable 25w-50 mineral ACEA A2 (and TBN 8) lubricant in these engines at this time. This is quite common practice when outside the Manufacturer's loop - I have seen this many times before and ultimately to the vehicle owner's detriment
It is well know that for the same reasons (valve actuating technology) the M96 engines are almost universally on a 0w-40 lubricant and with now many years of user and Warranty experience. No mineral lubricants have been Approved by Porsche since MY1999 yet my MY2001 Handbook lists a mineral 20w-50 lubricant option!
Porsche TISBs for non Cayenne V6 (VW) engines show around 30% are 0w-40 viscosity, 70% are 5w-40 viscosity with M1 5w-50 being the sole SAE50 lubricant Listed. And believe it or not M1 5w-50 is quite a different "animal" to M1 15w-50 from a "flow" perspective
Why doesn't Porsche advise Owners? - well they do via their Dealerships. In their Handbooks of recent years they also say "use only a Porsche Approved lubricant" or as such
glennc - Of course I totally agree with your comments
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I am sure that an approved lubricant is best or even a consumer tested option such as the Delvac 1 5W-40 would be ideal for some of these applications. But for someone who wants a quality 15W-50 for their air-cooled engines, an option to consider is Mystic HDEO 15W-50 CI4+. I have purchased this oil at Tractor supply, O-Reilly's, etc. and run it in several older, higher mileage vehicles including a '92 V8 MB. It is a "Synthetic blend", which probably means it has some percentage of GIII. Cost was about 18.50 for a 8 quart jug last time I saw it, which is a great price for a quality oil. The Mobil 1 15W-50 would have cost double that, and a PAO was not really needed in these apps.
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