I'm usually one to do a quick (<500 mile) oil change on a new vehicle, but I was having too much fun driving my GT4 to bother with that! So, Here's the analysis of the OEM oil after 3,709 miles—a road trip from L.A. to Reno, 12 autocrosses, four track days at Thunderhill, and a few fun drives:

by https://www.flickr.com/photos/sobiloff/, on Flickr

The lab hadn't seen the C40 Mobil 1 before, so they mistook it for the Delvac 1—which is interesting, as the C40 formulation does look a lot like the Delvac 1 upon analysis. I'm guessing that Mobil used their DPF experience to create this C40 formulation to protect the GPF, so the C40 spec is actually very similar to a diesel oil. The biggest difference is the low Mg sulfonate, which is a hallmark of the ESP oils.

Nitration was a touch high, so I need to check my air filters. Typical wear-in metals (iron and aluminum) are elevated, as expected in a new engine. Viscosity is too low for a 40-weight, but with a fuels dilute of only 1.6% it's probably from mechanical shearing (but would need to test a virgin sample to be sure).

Overall, the C40 oil did OK, but nothing spectacular—especially for the hassle I went through trying to find the Mobil 1 C40. I refilled the motor with Mobil 1 C40, but I'll probably try Liqui Moly after that. I'm not expecting the Liqui Moly to perform any better—in fact, I don't expect it to perform as well—but I bought some before I found the Mobil 1 C40 so I might as well use it up.

 

I will be the first to admit I am no oil analysis expert, but with Porsche recommending the first oil change at 10,000(!!!) miles, would you have been comfortable waiting that long? Or, looking at your results, would you have changed earlier than you did at 3700 mi? I am almost at 400 mi on my GT 4, not having gone above 4000 rpm so far. Ok, maybe once or twice...

 

My tribologist says I'm good for 4,000-mile oil change intervals on this oil given the way I use the car. Someone who only does cars and coffee could maybe suffice with the 10K mile / 1 year schedule, but with the observed wear metals I'd still want to do an oil change before that to get them out.

 

Might want to do 2 oil & filter changes at 4,000 mile intervals and send samples in for testing. Until the wear metals settle down, I personally would be changing the oil & filter at 4,000 mile intervals.

 

Thanks for posting this info. Has anyone found a higher viscosity esp oil to help with the shear? I've hit 10,000 miles with 1,000 of them on the track. Goes in this week for its 4th oil change.

 

This is very helpful!!! I have done with this my other German cars....I will be posting one hopefully end of this year from Blackstone!

 

I have been using Mobil 1 5-50 with great results for many years now. The higher viscosity holds up better than a 0-40 for track use.

 

@lovetoturn , I've only found the A40 spec in that weight, no C40. Have we even gotten an answer to the question can we run A40 oil in the 718 GT4? I would think so since we have the non active GPF models in the US, but I haven't seen anything to say its OK.

 

Yes, I would love to know this too. I have searched the web and this site and have found no definitive answer but common sense would say yes, we could.

 

https://rennlist.com/forums/718-gts-...-or-a40-6.html

There is a thread on this. There is a C40 recommended for higher ambient temps, 5W-40. That is in the owners manual too.

Cheers.

 

I'm getting my first annual oil change at a dealership I have never visited before and wondering if they would collect a sample for me so I can send to Blackstone. Are Porsche dealerships used to getting these kinds of requests? Can I bring my own container or is it a service they'd want to provide and charge a $100+ for?

 

I would ask your service manager; I've asked non Porsche dealers in the past and they are happy to oblige. I am about to ask/ provide bottle for sampling for my 2nd annual.


Cheers, M

 

Thanks, I'll do that when I make the appointment in the next couple of weeks. Is this something folks do at every oil change? I was only planning on doing the first.

 

I'm having the dealer do the oil changes during the warranty period, and have done two (March 2023 and 2024. I bought 4 cases of Mobil1 C40 ESPx3 right after I got the car in July 2022, and bring my own oil for the changes. My dealer got the oil from Porsche's warehouse in California for about $6/L. I give them the Blackstone container each time, they're happy to do it. Blackstone says the oil is performing excellent... I use the car mostly for the track.

 

Just for data points​​​, ​here is a screen grab from my first oil report. This is from a 4RS. The dealer I bought the car from had already changed the oil at about 1200 miles back in Oct 23. I had it changed at 2450 and this sample was taken then. I expect some break in metals to hang around for a few oil changes since only half the oil gets changed each time.