992 GT3 Oil - Page 2 - 911/Carrera GT - PistonHeads UK

Hi Everyone I'm aware that the 992 GT3 is recommended to have C40 oil, which used to be Mobil 1 ESP X3. This as recently changed as per the letter I got from Porsche and is now C40 GT. The trouble is, I really need to get some oil for the car today in order to drive it early on Monday morning and I'm really struggling to find C40 locally. This is just for a top up, rather than a full oil change, as mine has hit the low level where you get the warning. Does anyone please know if there is a Shell or Castrol equivalent that you can get at a garage or Halfords that would be ok to put in the car? Cheers

Just use the oil they have been using until oil change time,especially for just a top up,mine is still useing the original spec oil,so are many others.

I'm aware that I can "just use the oil they have been using until oil change time" - but the point is I don't have any and can't get any today. Is anyone aware of any other brands (e.g. Castrol/Shell) that would be suitable please?

Maybe someone who is relatively local to you has some oil you could have as long as you replace it. Where in the UK are you?

Thanks for the suggestion - I'm near Guildford, Surrey

Doesn't your OPC have it ? I recall that the C40 spec was the earlier oil for cars with particulate filters ... better to add a little (250ml max) and get the C40 GT than let it run too low ... As an aside, the oil measurement on the GT3 is notoriously inconsistent and the handbook recommends adding in very small amounts, then bringing the car back to temperature and reading again ... Overfilling is worse than a little under.

Thank you, luckily this issue has been resolved. I realised that my brother was close to Porsche Centre Mid Sussex (Burgess Hill) and long story short it turns out they had some of the C40 just on display inside the showroom. Amazing customer service from them, they kindly said I could have it for free. I would still be interested in knowing if there are other brands that can be used other than Mobil 1. It's massively frustrating not being able to buy some at Halfords or at a Shell petrol station. I wouldn't mind if Porsche retail was available all weekend, but whatever centre you call, they always say you have to get it from their Parts department and "oh sorry that closed at 12pm and isn't open again until Monday". What's an OPC please?

jkftype said: What's an OPC please? Official Porsche Centre

https://www.opieoils.co.uk/c-4839-porsche-c40-engi... Hopefully this helps you.

cuprabob said: Official Porsche Centre Ah ok - thank you. They don't seem to be open on a Sunday anymore (at least the ones near me), and as above the parts department always shuts at 12pm on a Saturday. So no good if like me you find out you're low on oil on a Saturday afternoon. I got lucky with Burgess Hill. They told me they are normally shut on a Sunday but were open today due to an event. Also just a follow up question if someone could please help. I have rather stupidly spilt a bit of oil when filling, a little bit (10ml maybe) went down the gap between the plastic and the adjacent cap (I think that's coolant). Is that a huge problem? I can't have been the first person to have done this, but still feeling pretty stupid as I did use a funnel before. Cheers

There does seem to be a nationwide shortage of the Mobile 1 C40-spec oil. Opie Oils was the only place I could find that had some stock.

The new oil is not just C40, it's a new standard C40 GT ... I'm not aware of the difference but Porsche suggest that it matters because they have even issued a supplement to the User Manual. Their original advice was that any remaining C40 oil purchased before mid February '24 could be used until the C40 GT arrived. It's possible that this has been driven by a number of particulate filter failures ... particularly on cars where this includes the turbocharger and the replacement is therefore very expensive ... and a consumable so excluded from the warranty.

ChrisW. said: The new oil is not just C40, it's a new standard C40 GT ... I'm not aware of the difference but Porsche suggest that it matters because they have even issued a supplement to the User Manual. Their original advice was that any remaining C40 oil purchased before mid February '24 could be used until the C40 GT arrived. It's possible that this has been driven by a number of particulate filter failures ... particularly on cars where this includes the turbocharger and the replacement is therefore very expensive ... and a consumable so excluded from the warranty. I don't think GPF failures and any consequential turbo damage are a reason for the new C40 GT spec. Firstly, the GT spec is only for naturally aspirated GT engines (even the GT2 is not listed) and secondly the spec now applies to models well before the GPFs were introduced. Pure speculation on my part, but my best guess is the C40 GT spec has better wear protection at high rpms. I would expect the SAPs level / GPF compatibility to be the same for both C40 and C40 GT. C40 GT specified for : • 911 GT3 (991 and newer) • 911 GT3 Cup (991/992) • 911 GT3 R (991/992) • 911 GT3 RS (991 and newer) • 911 RSR (991) • 911 R (991) • 911 Speedster (991) • 911 S/T (992) • 718 Cayman GT4 RS (982) • 718 Cayman GT4 RS Clubsport (982) • 718 Spyder RS (982)

True --- it has been specified on my 991.2 GT3RS which is pre-GPF and the for which the User Manual specified the earlier Porsche A40 grade ...

I have a ‘21 992 GT3 - it had only done 1500miles when I bought it but just a few days ago asked for an oil top up - I bought the Mobil 1 C40 0w-40 as in the manual/sticker. I’m guessing it’s post Feb ‘24 that it was made - I put in 500mls as that’s what it took to get it back in the green. I’m heading off into Europe for about 2000 miles - I’m guessing with just a top up it’ll be alright as the old oil will still be the pre ‘24 C40 will still be in the car….just a bit paranoid as I scream up the mountains at 9k 😬 The GT oil seems almost impossible to locate. Any thoughts?? Cheers.

Continue with old oil until you can get hold of the new stuff. You’ll need multiple changes to get to full fill of the new stuff any way as the GT3 system generally only lets out about 1/2 the capacity anyway on a change, unless you let it drain out over extended time and open up some of the other oil retaining areas.

Back from Spa 24 another run and still no sign of ever needing oil once in over 28k miles , but interesting story the Oil one .

I could be wrong but my understanding having looked into this quite a bit recently is that the X3 oil has changed its mixture to be more environmentally friendly and is such isn’t recommended for the 9k limit cars. It looks like this is now replaced with X4 which is suitable for all that user the old X3 oil with the exception of the 9k rpm cars which should use the new GT oil (which is red). In reality you are putting in so little that I can’t see it making a difference, maybe 300ml into a sump with probably 8/9 litres. I’ve got a 718 GT4 and it looks to not need the new GT oil (I’m suggesting due to the lower rev limit) so it looks to be ok to use the new X4. In short - it’ll be diluted enough that you’ll be fine.

Great, I thought the same myself but just wanted to hear other opinions 👍🏼

Interesting thread. My 991.2 gt3 says A40 oil in the owners manual, has that been also superseded by the C40-GT as well, given it mentions it’s above on that link?

mikeh501 said: Interesting thread. My 991.2 gt3 says A40 oil in the owners manual, has that been also superseded by the C40-GT as well, given it mentions it’s above on that link? Yes, there should have been a new section of the owners manual sent out to cover it (or you’ll get it next time it’s in for a service - assuming OPC)

Yes, ultimately.

Yes, owners of GT cars got a letter from Porsche

I didn’t, but perhaps it was 992 only. I phoned the Wolverhampton and wilmslow yesterday, both less than useless.

I did .. recently purchased 991.2 GT3RS ... interestingly a pre-particulate filter car requiring A40 spec oil ... until C40GT was specified ...

Do you have a pic of what you received?

I had my 2018 RS serviced by Porsche Chester last week and I was given the manual supplement. The oil listed on the invoice was the new C40 and an extra 1L bottle was included (as a paid item, naturally!) The manual only has one block of information, but it's in every supported language so there's a few pages to it.

many thanks

Just arrived in suffolk after 140mile drive and low engine oil warning has come on the dash (992.1 gt3) Spoke to porsche colchester but was after parts closed and they said cant advise if they have any until Monday. Im driving home Monday am and will stop off there but i bought a bottle of mobil 1 0w-40 fully sythentic, anyone used this as an emergency? No idea if porsche colchester have any either so need something for journey home.. Amy thoughts?

A quick google search shows that the C40 is slightly different and therefore not suitable for the GT3. Standard C40 (Mobil 1 ESP X3 0W-40): This is the approved oil intended for the 4.0L engines found in the standard 718 GT4, Spyder, and GTS 4.0 models.C40 GT (Mobil 1 C40 GT 0W-40): This is a specialized formulation engineered specifically for the 9,000 RPM Porsche GT engines (like the 718 Cayman GT4 RS and GT3). It is not meant for the standard GT4 and is actually not backwards-compatible with standard C40 engines

Basically the C40 oil specification got changed so it was more environmentally friendly which is fine for the Carrera engines but the GT3 requires a better drink so they used the older oil and rebranded it as C40 GT... so the upshot is that you can't use the normal stuff.

FWIW: My 991.2 GT3 RS is now recommended to use the C40 GT spec, although it’s 2018 and pre OPF. I did an engine oil change just after I got the car, because it’d been a bit of a ‘cars n coffee’ motor, so not done much work, definitely never been on track, but also not quite on front foot with service (I also had to bleed brakes too, but that’s an aside). It was only when I was pouring the stuff in that I had a panic - the new C40 GT oil isn’t the normal yellowish gold Mobil 1 colour, it’s green. There was a moment where I thought I was throwing anti freeze in. Just in case anyone else is using this oil for first time.