Where to buy the new Mobil 1 C40 GT Oil ? - Page 1 - 911/Carrera GT - PistonHeads UK

Now required exclusively for all cars using the 991 and 992 GT3 engines ...

P.S. Is there a clue in the future of this engine in 911 GT3RS models only ... 991 and newer models (rather than just 991/992) ??

Short answer - nowhere yet. I got the letter too, and sure enough my RS decided it wanted an oil top up a few days later (almost like it knew this wouldn't be simple). Nowhere online has it, outside of stores in Germany. A few suggestions on Rennlist to get it from Porsche themselves so I swung by OPC Chester and they didn't have any yet. Spoke with a technician and they were aware of the change but hadn't seen the letter so he took a copy to take it up with Porsche GB why they were telling customers to use oil thats unavailable. I needed some and he suggested to just use what they'd been using on the GT range previously. He kindly supplied me with a bottle of Mobil 1 0w 40 FS at a discount to compensate for the runaround. Whether this is the old, previously correct oil or a now unsuitable one I don't know, but he was confident it would be OK and I have documentation in case of issues in future.

26,000 miles on my .2 RS , a dozen track Days and still never needed to put a drop of oil in the engine in 6 years ( Only at service oil changes ) .

hunter 66 said: 26,000 miles on my .2 RS , a dozen track Days and still never needed to put a drop of oil in the engine in 6 years ( Only at service oil changes ) . Its now f ked then mate Its probably got a higher ester content than the standard watery oil,it a laugh gt car oil for extreme use parked up

hunter 66 said: 26,000 miles on my .2 RS , a dozen track Days and still never needed to put a drop of oil in the engine in 6 years ( Only at service oil changes ) . I had the same with my GT4 (obviously not the same engine) ... mine needed around 200ml adding between oil changes at around 4000 miles and multiple track days ... but there have been tales of GT4RS using quite a lot of oil ... ?

The new engines DO require a full low/med revs run in, due to the piston clearances that allow them to rev so freely. If you don't run in gradually over time, the seating and surface mating isn’t optimal and will allow oil migration. There have been couple social media pieces on this in recent months from the likes of Dundon, where they get into the particulars of these engines, design choices and then what this means for making power.

So the new engines are sensitive to being run-in correctly ... but from what built point has this become significant ? After the shut-down in ?? or ??? This might not bode well where there have been multiple owners within or close to the running-in period ... not intending to keep the car ?

TDT said: The new engines DO require a full low/med revs run in, due to the piston clearances that allow them to rev so freely. If you don't run in gradually over time, the seating and surface mating isn’t optimal and will allow oil migration. There have been couple social media pieces on this in recent months from the likes of Dundon, where they get into the particulars of these engines, design choices and then what this means for making power. Yes ran mine in very carefully .... nice long run to Le Mans to race the GT2

ChrisW. said: So the new engines are sensitive to being run-in correctly ... but from what built point has this become significant ? After the shut-down in ?? or ??? This might not bode well where there have been multiple owners within or close to the running-in period ... not intending to keep the car ? Agree a mate only did 600 miles on his GT3RS but all were on track at 9k so good run in . My GT3 RS 2001 race car used about a pint an hour ....

Can the new c40 GT oil be used as a small top up and be mixed with original oil that is still in the sump from the factory? My car is now 12 months old and at 960 miles

Yellowcab said: Can the new c40 GT oil be used as a small top up and be mixed with original oil that is still in the sump from the factory? My car is now 12 months old and at 960 miles That's embarrassing, go for a drive this weekend and enjoy the car,

Yellowcab said: Can the new c40 GT oil be used as a small top up and be mixed with original oil that is still in the sump from the factory? My car is now 12 months old and at 960 miles Just use the old make until next service,its clearly not going to hurt, especially with your low use. I would change my oil at 1 year old anyway.

Porsche have said that it's OK to continue to use (top-up ?) with any C40 / VW 511 00 spec oil purchased before 1/2/2024. My 2018 car says it needs A40 spec oil ... there is no mention of the car having a GPF filter or GPF re-gen warning light, which was the reason why the oil spec changed to C40 ... the `Mobil 1 green top Esp-X3 oil ... in order to protect the GPF. Now that this has been upgraded to C40 GT and the letter from Porsche states my car's vin number, I just hope I don't need a top-up before the C40 GT oil become available. But it's a bit of a blooper by Porsche ... 'still waiting for a reply ... Apparently there is also a Users Manual Supplement, so Porsche are taking it quite seriously. Since my car was serviced only a few months ago, I assume that it will be filled with C40 or C40 GT oil, and the question of compatible top-up is yet to be answered. I do have A40 for top-up but ... dare not use it.

Update from those kind people at OPC York ... Thankyou ! My car is before the GPF so it is fine for me to use the A40 New Life version of Mobil 1 until the new C40 GT oil arrives ... but others will need to check because it appears that the build spec to include the GPF and ITB's changed later in May 2018 ... Cars with the GPF must use the C40 Esp-x3 oil until the new C40 GT oil arrives. Edited by ChrisW. on Thursday 4th April 14:01