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I will add my oil anaylsis to this thread, since this is probably the most comprehensive oil sample analysis on an Rennlist sub forum. To be clear it's a 991.1 GT3 RS, with the oil that I bought the car with. A porsche dealer did the last oil change, so I would assume Mobil 1 0w40 Euro, but Blackstone disagrees.
I changed it to Mobil 1 5W50 FS X2 Euro. The advice I need is what oil next. I am debating between Driven DT 40, DI 40, or FR 50. The 991.1 GT3, and to a lesser extent RS suffer from Finger Follower Wear between the Finger Follower and the Camshaft. On the oil regime stribeck curve, it's a low speed, high load application, so boundry layer / addtive important. Likewise, high oil shear strength is important. My application is spirted road driving on weekends, started in 50F +. The GT3 engines shear the heck out of the oil with their 9k redline. Oil will be changed less than every 2500 miles.
DT50- High ZDDP, Moly, lower HTHS, than DI40. DI40 has lower ZDDP, lower moly, but actually higher HTHS. FR50 appears to be DT50 with a higher viscoity. I really like the FR50, but I want to take advantage the FCP euro oil change life time options. However, if FR50 is going to help, I would consider it, but it seems very thick compared to a regular 5w50.
Driven themselves recomened DT40 for the A40 application. Lake Speed JR, recomended DI40. What say y'all?
Thanks!
I'll also attach some A40 application possilble virgin VOAs. Before the driven DT40, I was also comparing Mobil 1 SuperCar 5w50, Mobil 1 FS x2 5w50, Motul 300V, and DT50.
Hello. 991.1 GT3 RS is direct injected. The appropriate oil for street use in this engine is DI40 and for track use XP6 or XP9. Your wear should come down when you switch.
Hello. 991.1 GT3 RS is direct injected. The appropriate oil for street use in this engine is DI40 and for track use XP6 or XP9. Your wear should come down when you switch.
Silver TT I appreciate your response. In my search on rennlist, you have a lot of insightful, valuable inputs on oil.
Lake Speed JR has the same feedback as you, DI40, however if you ask Driven, they say DT40 is meants for A40, and DI 40 is meant for C40 applications. The 991.1 GT3 RS is A40, no particulate filters, just cats.
I think the DI40 is a better oil. It seems to have lower wear than DT40. I read that long thread and watch the video where DI40 is a better base oil. However, it has less ZDDP, especially Zinc, and Zinc seems to be the key ingredient that protects the valvetrain. The biggest wear on the 991.1 GT3 and RS seems to be the valvetrain. The rest of the engine, seems to be solid.
Given the need for high ZDDP in 991.1 GT3 applications, would you still recomend DI40 over DT40?
You are very welcome. Yes, I 100% would run DI40 in your engine. It will not harm your cats, I have been running it for 60K+ miles. The Zinc and Phosphorous levels are slightly lower in DI40 vs DT40 but that is no problem as its chemistry has been optimized.
For that few miles, Iron & Copper are kind of high which we see with Mobil 1 frequently and the hot viscosity is low for a 40 weight so it's shearing down. Glad you're looking to switch oils to Driven.
Normally, anytime it's a DFI Porsche engine the default is DI40 and what I use in my Cayenne Turbo S and Audi Q5. However in your case with the track use and high rpm threshold, I think FR50 5w50 might be the best choice. That's what I run in my supercharged 997 for the higher hot film strength and better shear stability, but it's not DFI.
DT50 definitely isn't the right choice as it's a 15w50 - I use that in a 914, 2 928s, a 944 S2 and a wakeboat, but the 15w cold viscosity is too thick for a modern Porsche engine
I would ask Charles Navarro at LN what he'd recommend as he now does the Tech Support for Driven oils.
For that few miles, Iron & Copper are kind of high which we see with Mobil 1 frequently and the hot viscosity is low for a 40 weight so it's shearing down. Glad you're looking to switch oils to Driven.
Normally, anytime it's a DFI Porsche engine the default is DI40 and what I use in my Cayenne Turbo S and Audi Q5. However in your case with the track use and high rpm threshold, I think FR50 5w50 might be the best choice. That's what I run in my supercharged 997 for the higher hot film strength and better shear stability, but it's not DFI.
DT50 definitely isn't the right choice as it's a 15w50 - I use that in a 914, 2 928s, a 944 S2 and a wakeboat, but the 15w cold viscosity is too thick for a modern Porsche engine
I would ask Charles Navarro at LN what he'd recommend as he now does the Tech Support for Driven oils.
hanks for the feedback. Even though the .1 GT3 RS is DI, but not a turbo, NA 4.0 L reving to 8650 RPM, the oil spec is a40, and if you look at forumulation, and driven will tell you themselves that DT40 is meant to replace A40. DI40 is meant to replace Porsche C40, which is when Porsche added the particulate filters, and lowered the ZDDP to not clog them. Lakespeed, agreed that DT40 is technically the correct "Spec sheet" for the a40 replacement, but he said from Oil Analysis, DI40 does a better job wearing accross the board on Porsches.
I have reached out to LN Engineering. They (Not specifically Charles) recomended FR50 as well. The said it has higher ZDDP and Moly than even DT40, but I have not seen a VOA for it. Anyone have a link? In the manual for the 991.1 GT3 / RS 5w50 is an acceptable oil spec.
My car is not a daily driver. It's just a spirted backroad driver, and may do track time this summer.
The reality too is this engine wears it's oil fast (hence the need for better oils), and the wear especially Iron tends to be high. You can see the 991.1 GT3 Oil analysis thead here, very limted in info as everyone really that has posted runs either Mobil or Moly. The prevailing wisdom is Motul is the "best" oil for the GT3 RS 991.1, but I am thinking the Driven 40 series is better. FR 50 maybe even better.
Thanks, my bad, thought it was turbo charged. Either way, it does not change the fact that I would still run DI40 in that engine on the street. It would get XP9 on the track as well. There are several things unique to direct injection engines and they require "special oils", turbo charged or not. Charles may opine as well, but Lake is spot on here as he always is with oil recommendations. DI40 is more mPAO. I highly suspect it uses alkylated naphthalenes as well. Not to be dramatic about it but this really is "God's oil" in the sense that the molecules are built from scratch at the atomic level. Pretty incredible that is possible when you think about it....
hanks for the feedback. Even though the .1 GT3 RS is DI, but not a turbo, NA 4.0 L reving to 8650 RPM, the oil spec is a40, and if you look at forumulation, and driven will tell you themselves that DT40 is meant to replace A40. DI40 is meant to replace Porsche C40, which is when Porsche added the particulate filters, and lowered the ZDDP to not clog them. Lakespeed, agreed that DT40 is technically the correct "Spec sheet" for the a40 replacement, but he said from Oil Analysis, DI40 does a better job wearing accross the board on Porsches.
I have reached out to LN Engineering. They (Not specifically Charles) recomended FR50 as well. The said it has higher ZDDP and Moly than even DT40, but I have not seen a VOA for it. Anyone have a link? In the manual for the 991.1 GT3 / RS 5w50 is an acceptable oil spec.
My car is not a daily driver. It's just a spirted backroad driver, and may do track time this summer.
The reality too is this engine wears it's oil fast (hence the need for better oils), and the wear especially Iron tends to be high. You can see the 991.1 GT3 Oil analysis thead here, very limted in info as everyone really that has posted runs either Mobil or Moly. The prevailing wisdom is Motul is the "best" oil for the GT3 RS 991.1, but I am thinking the Driven 40 series is better. FR 50 maybe even better.
Based on your use case, I would use the FR50 for higher film strength, as I do, but see what LN says. I don't track my cars either.
I used DT40 in my DFI Cayenne for years with fantastic results before switching it over to DI40, but haven't driven enough miles to get the first DI40 comparison yet.
Here's the UOA history with the first sample.being M1 Euro 0w40 I bought it with and the rest DT40.
The virgin sample DT40 has a ~13.2 cSt viscocity @ 100 C. I am surprised it has sheared down under 12 cSt in 5K mile OCIs.
I run DI40 in 2-3K mile OCIs but even when I was running 5K mile OCIs with close to 2% fuel dilution it didn't shear down at all vs the virgin sample. Another important consideration is that DI40 is ~14.0 cSt @ 100 C, significantly more viscous.
It is only my opinion but speaking from a chemistry standpoint there is nothing DT40 does better than DI40. Not a single thing. The only attribute it wins on is price, and the cost difference is negligible.
FR50 has been very good to me. Below is some historical UOA from it. My car is driven all year round and typically driven hard. FR50 has produced some solid viscosity over time and seems to last for me 5k or less oil change intervals. Petty solid Moly and ZDDP numbers as well.
The virgin sample DT40 has a ~13.2 cSt viscocity @ 100 C. I am surprised it has sheared down under 12 cSt in 5K mile OCIs.
I run DI40 in 2-3K mile OCIs but even when I was running 5K mile OCIs with close to 2% fuel dilution it didn't shear down at all vs the virgin sample. Another important consideration is that DI40 is ~14.0 cSt @ 100 C, significantly more viscous.
It is only my opinion but speaking from a chemistry standpoint there is nothing DT40 does better than DI40. Not a single thing. The only attribute it wins on is price, and the cost difference is negligible.
We'll see next year when I have a DI40 sample to compare to this DT40 history. This isn't a regular Cayenne - it's a modified 650 HP Turbo S so might be rougher on oil than others.
We'll see next year when I have a DI40 sample to compare to this DT40 history. This isn't a regular Cayenne - it's a modified 650 HP Turbo S so might be rougher on oil than others.
Awesome, can't wait! Thank you and all the others for sharing this data. This is literally one of the best threads on RL, so much data here it is outstanding, so thank you all who posted here making this thread what it is.
Has anyone seen a Blackstone VOA or used analysis of DI40 from Blackstone? I appreciate the SpeedDiagnostix, it gives me a ball park, but I want to see in an apples for apples how much zinc it has. I have found a bunch of DT40 Blackstone, but not DI40.
The lower Zinc on the DI40 has me concerned with FR50. I do like that FCP euro sells DI40, so that makes it more desireable. IT is very ineteresting that DI40 has a higher viscocity than DT40 when warm, but a lower winter rating.
If only DI40 had the zinc of DT40, I would feell 100% comfortable just buying it. FR50 feels like the safer bet. Hard part is I only put 1500 miles a year on this car, so the resulting wear analysis trend will take like 5 years! lol.
01-18-2024, 07:38 PM
