996 Turbo 10w-60 Oil - Page 2 - 911/Carrera GT - PistonHeads UK

Just had the TT serviced at a very well regarded independent. Has 84k on the clock, drinks a little oil but within acceptable levels. Just noticed that they put in 10w-60 Mobil 1 Extended Life which isnt a viscosity recommended by Porsche. Did a few forum searches and threads seem to descend into slanging matches / no real conclusion that helps settle my mind. Thoughts appreciated.....

Most of the Indys are using 10/60 in the GT3s so given the Turbos can run slightly hotter if driven in anger, I think you'll be fine. It's probably a little overkill unless your tracking it hard in hot climates but given yours has done average mileage and is using a little oil, you may find it'll use less now. The Cold start thickness won't be an issue unless we suddenly hit -20C. Mine has been on 10/60 for years but the Indy used 0/40 at last service and the only difference I can see is the hot, idle oil pressure is slightly lower than it was before. I may try 5/50 at next service as a happy medium.

On the US forums, some 996T owners used 0W40 Mobil One Turbo Diesel oil instead of the petrol version to good effect. I think only the 0W40 and 5W50 is Porsche approved. I use 0W40 Mobil One petrol version and I find oil consumption increase after c.4000 miles after oil change which suggests to me the oil is sheared and needs changing. Mine is my winter daily hack, 4 miles each way twice a day in central London with a once a month hard country drive so it is hard on oil.

It is the wrong oil. Porsche does not approve the use of any 10w-XX, 20w-XX, 0w-60, or 5w-60 oil in that engine. The Turbo engine has a complicated VarioCam Plus system -- variable valve timing and variable (low/high) lift which is changed on the fly. Both the variable valve timing and low/high lift is controlled by oil pressure/flow and the proper viscosity is critical for this hardware. Porsche tested this hardware to 250,000 cycles which IIRC Porsche believed would equate to one millions miles. But I seriously doubt it tested it with 10w-60 oil. You won't like to hear this but I'd take the car some place else and get the proper oil in the engine and give that 1st shop a wide berth. BTW, the Turbo engine doesn't run that hot. My Turbo engine runs cooler than my Boxster. About the only concession I make regarding oil viscosity where I live and drive is I run 5w-50 Mobil oil (an approved oil) in my Turbo and my Boxster. But winters here are mild and it can get up into the very high 90's even the low 100's here.

Mine runs 10-60 as fitted and recommended by Matt at Fearnsport. I would imagine he knows his stuff better than most. Not used any oil in just over 1000 miles,,,,,,,,,,,,,, so far. I would imagine when summer arrives and after a good thrash, the 10-60 would be a bit kinder to the engine?

This is worth a read: https://www.opieoils.co.uk/pdfs/tech-articles/10w-...

Thanks boxsey - that's a top link

Mark A S said: Mine runs 10-60 as fitted and recommended by Matt at Fearnsport. I would imagine he knows his stuff better than most. Not used any oil in just over 1000 miles,,,,,,,,,,,,,, so far. +1 Matt runs all 3 of my GT cars on 10/60 - I've been using it for years with zero problems. There's lots of tosh about oil sloshing about on forums but whatever you choose to use, changing it frequently (4-8K miles) is probably the best advice of all.

Rockster said: BTW, the Turbo engine doesn't run that hot. My Turbo engine runs cooler than my Boxster. . Rockster, I was comparing it directly to the N/A unit in the GT3, not a completely different engine in a completely different car. I'm betting you could easily see oil temps above 130C when driving the turbo hard and this is where most 40 weights will start to shear. Granted the modern group V ester oils are much better at higher temps in a 40 weight but strictly speaking these aren't Porsche approved for the engine either ??

nxi20 said: Mark A S said: Mine runs 10-60 as fitted and recommended by Matt at Fearnsport. I would imagine he knows his stuff better than most. Not used any oil in just over 1000 miles,,,,,,,,,,,,,, so far. +1 Matt runs all 3 of my GT cars on 10/60 - I've been using it for years with zero problems. There's lots of tosh about oil sloshing about on forums but whatever you choose to use, changing it frequently (4-8K miles) is probably the best advice of all. Same here, run Mobil 10W60 in all the GT engines. Zero issues.

Yes had read that Opi article and also seen quite a few quality Indis using 10-60. On balance I am not worried about using 10-60 until next service but will ask them to move back to recommended by porsche range at next service unless there is some logic I am not aware of. Cheers for comments.

It seems to me that one of the complexities is that synthetic oils are often not fully synthetic any more - but in fact semi-synthetic (and possibly variable by geography too). So choosing a fully synthetic oil seems to require the phrase "top end ester based synthetic oils" these days. This debate was on here before and iirc was saying thet even Mobil 1 in the UK is really semi-synth, not fully. And yes there are the downsides described in OPI article, but how severe are they? How critical is it to have the right oil? How bad is a 60 when a 50 is specified? Dunno. Bert

ArcticGT said: Rockster, I was comparing it directly to the N/A unit in the GT3, not a completely different engine in a completely different car. I'm betting you could easily see oil temps above 130C when driving the turbo hard and this is where most 40 weights will start to shear. Granted the modern group V ester oils are much better at higher temps in a 40 weight but strictly speaking these aren't Porsche approved for the engine either ?? Oil shear is the cutting of polymer chains in mehanical parts meshing together AFAIK so I don't understand how shear is temperature related.

I use Motul sport ester 5W50 fully synthetic in my GT engines.

I'm surprised no-one's mentioned Millers yet, the experienced independents that have tried it (often for motorsport use too) swear by it.

Isn't the problem that with so few engine problems at all we all think whatever magic formula we've happened on must be the winner? Racers excepted who have stuff measured and rebuilt but have a very different usage profile to everyone else, I struggle to accept that anyone really knows if their oil formula is better than anyone else's. Seems Porsche recommend some oils and using from that list should be fine

My Mk1 GT3 was owned by Manthey from day one and then maintained by them until I bought it. All I see in the service history is Castrol RS 10W60. Somehow I have the feeling Manthey have forgotten more about the Mezger than we would ever know...

Well that's good information for sure. I'm intrigued about the science behind the 60W and why Porsche don't recommend that. What was the amient temperature where the car used to live?

thegoose said: I'm surprised no-one's mentioned Millers yet, the experienced independents that have tried it (often for motorsport use too) swear by it. I use Millers synthetic motorsport gearbox oil

Rockster said: It is the wrong oil. Porsche does not approve the use of any 10w-XX, 20w-XX, 0w-60, or 5w-60 oil in that engine. The Turbo engine has a complicated VarioCam Plus system -- variable valve timing and variable (low/high) lift which is changed on the fly. Both the variable valve timing and low/high lift is controlled by oil pressure/flow and the proper viscosity is critical for this hardware. Porsche tested this hardware to 250,000 cycles which IIRC Porsche believed would equate to one millions miles. But I seriously doubt it tested it with 10w-60 oil. You won't like to hear this but I'd take the car some place else and get the proper oil in the engine and give that 1st shop a wide berth. BTW, the Turbo engine doesn't run that hot. My Turbo engine runs cooler than my Boxster. About the only concession I make regarding oil viscosity where I live and drive is I run 5w-50 Mobil oil (an approved oil) in my Turbo and my Boxster. But winters here are mild and it can get up into the very high 90's even the low 100's here. You've said this before and its not true - fancy also suggesting the OP gives the Indy a wide berth when you have no idea who it is. On an older engine its actually quite sensible to use a slightly thicker viscosity oil. Yes you've completed 1000,000 miles on your original engine but everyone drives their cars differently. you obviously have a very sympathetic style of driving judging from many of your posts and your cars always gets warmed through properly and used on longish journeys, Here in bumper to bumper rush hour stop start traffic engines can get awfully hot. Different world my friend.

vanman1936 said: Just had the TT serviced at a very well regarded independent. Has 84k on the clock, drinks a little oil but within acceptable levels. Just noticed that they put in 10w-60 Mobil 1 Extended Life which isnt a viscosity recommended by Porsche. Did a few forum searches and threads seem to descend into slanging matches / no real conclusion that helps settle my mind. Thoughts appreciated..... Who's the Indy? JZM?

Steve Rance said: I use Motul sport ester 5W50 fully synthetic in my GT engines. Motul is the ticket, Motul 300V is used by the majority of racers, especially good against fuel dilution. As previous poster said more frequent oil changes are the way to go. Edited by TB993tt on Tuesday 3rd March 13:33

It's a shame we don't have someone on here who routinely tears down engines. It's useless hearing "I've always used XYZ and my engine never blew up so I swear by it" because pretty much any Mobil 1, Castrol, Shell, Total, Motol, even I'll bet Comma, when changed regularly and under reasonable usage conditions (i.e. used mostly when warmed up, not thrashed from cold, not too much stop/start abuse) will achieve the exact same result. The bore scoring / IMS problems seem to be common issues but caused by manufacturing or design issues, not oil, and I bet most issues are to do with bad usage rather than oil.

Comma and Mobil are the same company, by the way

supermono said: Well that's good information for sure. I'm intrigued about the science behind the 60W and why Porsche don't recommend that. What was the amient temperature where the car used to live? I dare not question Manthey's logic - when you think about their involvement with Porsche, and the Mezger engined cars in particular, I could not be seen as the smart arse asking question. The car lived at the Ring and Spa - 27k miles from new, so ambient temps similar to the UK I would say, if a little hotter in the Summer. It was Olaf's personal car for a while... Just another snippet of info - used to have Ring-Racing look after my other cars - they also know an awful lot about engines being in a very harsh operating environment. All the 911s they looked after were filled with Castrol 10W60, as well as all BMWs (the latter to be expected). One of the main reasons being was that the Castrol 10W60 was very good when it came to fuel dilution due to the engine spending a lot of time at WOT. Worth noting that they would change the oil after each VLN race anyway...

supermono said: It's a shame we don't have someone on here who routinely tears down engines. These guys do it quite frequently: http://www.pomotec.de/leistungen/wassergekühl... They give a guarantee for their engines but require them to be run with 10W-60. Best Christian

watercooled said: http://www.pomotec.de/leistungen/wassergekühl... They give a guarantee for their engines but require them to be run with 10W-60. Best Christian Where does it say that, it seems that they use Motul products for their servicing ?

I've been to one of their workshops. They told me, that they require owners of Pomotec-rebuilt engines to run 10W-60 oil. A specific brand was not mentioned though, so I guess it does not make a difference if it is Motul or Castrol. Feel free to call or email a them to verify this statement. Best Christian