Another oil question thread, please don't shoot me UPDATE: use DT40 for 987.2 2.9

The only reason I'm asking this is I've googled, and can't find a straight answer. In my 997.2 C2S, I use 5W-40 Driven DI40 oil, because the motor has direct injection. In my 987.2 2.9, which is not direct injection, I've been using Liqui Moly 5W-40 Leichtlauf High Tech. If I were to switch to Driven in the Cayman , I'm thinking the DT40 would be better than the DI40, because my engine isn't direct injection. Am I on the right track here? I don't know. I'm at a loss, and I can't get a straight answer from anyone.

The short answer is I would use the DI oil in your 2.9, but using any other high quality Porsche A40 approved or recommended oil is fine too. The 2.9 9A1 engine is a bit of a unicorn because it’s the non DFI outlier, but it’s extremely unlikely to have bore scoring. A very forgiving engine with very low likelihood of problems means that you don’t have to split hairs when it comes to oil. You will be fine with any high quality oil. But if you want to split hairs, here is a great explanation. Nickies Lite for Boxster Cayman 987.2/981 and 911 997.2/991/991.2 Models with the 9A1/9A2 MA1/MA2 Engine LN Engineering’s Nickies are the solution to bore scoring and other cylinder issues in 2009 and later Porsche Boxster, Cayman, and 911 MA1/9A1 engines. www.lnengineering.com

That's a good question, @theblooms -- I'll be following this thread, to be sure. First off, you do indeed get an exemption from the "best oil" thread here (LOL), as the bore score issue does exist for and is a specific and a problem for DI cars. Likely not our 2.9L (EFI) cars, and this is likely a "developing story" over time as to see what works and if/what bore scoring data comes in over time. In fact, for my 981 Outlaw (991.1S engine, DI) I'm likely going to finally switch it up to 5W-40 Driven DI40 from Mobil 1 this year as I don't think it could hurt. Remember -- it's not just about EFI vs DI, but it's also about the cylinder wall alloy that was used in any given car and the pistons (I think). First up, you might want to give Driven a shout and see what they say (and please report back here if you do). It says that DT specifically says that is NOT for use on DI cars, so that's probably the correct choice. Either way, keep in mind that Driven is not cheap at ~$20/quart (either DT or DI) and our cars require a lot of oil. @deilenberger has said that the 5W-40 helps with the loud lifter tick at start, which sounds like a good idea. My guess is that a lot of people with the 2.9L don't bother, as it's a pricey proposition for a problem that doesn't seem to exist -- which is why you may not be reading about Driven DT in 2.9L cars -- as most everyone may be standing pat with Porsche's initial Mobil 1 0W-40 recommendations. Hope that makes sense. I sometimes do have a similar question about my 987.2 2.9L, as to if/what the ideal Mobil 1 0W-40 replacement might be. Meanwhile, as it's EFI and there's likely no bore scoring issue, I'm far less concerned about making a change there and might just stick with the significantly less expensive and readily available Mobil 1 0W-40. If it is any help, so ideally you don't lose sleep at night -- from what I can tell, my 2.9L spent 240K+ miles of its life down south near you (similar temps). I'm going to assume that it was dealer changed with Mobil 1 0W-40 and nothing fancier, and the engine still has a good bill of health per Blackstone results. This might be a case of "if it 'aint broke, don't fix it." For whatever reason, I've encountered a bunch of people lately with the 2006-2008 987.1 S and I generally recommend that people take such precautions as using expensive 5W-40 Driven DI40 to play it safe. But for anything outside that, at this point in time and with the data that has come in, there may be far less urgency to move away from M1 0W-40. I could be totally wrong here, but YMMV.

I did reach out to Driven, and this is the response. The tl;dr response is, DT40 for the 987.2 2.9, not DI40

@theblooms -- Glad they were able to confirm it as we suspected. However, Driven's reply was actually important to read in its entirety -- thanks for posting it as they did have an important caveat! TBH, I think I personally may skip the DL and go for the 5W-40 Liqui Moly for the 2.9L, given the DL's Zn/P chemistry -- and the potential to eventually damage the cat/O2 sensors. If I was racing, I'd likely be going catless (no catalytic converters) with no expensive cats to damage. I'm far less concerned about O2 sensors, which are inexpensive and easy enough to replace. This being said, I may ultimately go with the Driven DI-40 for the 3.8L though; we'll see. Let us know what you decide to go.

That is exactly what I was thinking. The bore score issues is almost if not entirely unheard of with the 2.9, so I'll probably stick with the Liqui Moly. My 997.2 gets the Driven though, because though bore score is very rare in the 3.8, unlike the 2.9, it's not unheard of. If I burn a cat, I'm out $1500. If I burn a cylinder, I'm out $20,000! I'll take the gamble!

I have the Cayman S (EFI) and the Cayenne DFI. I use the same quality oil in both. No issues.

Correct, in the DFI motors like the 3.4, use DI40.

Following this thread, as choice of oil brand, grade, and viscosity is one of the most discussed topics on this forum. Have questions concerning my ride and some of the topics recently brought up here. Mine is a base Boxster , 2.7l engine. What is the fuel delivery system, EFI or DI? Some discussion here on oil choice based on whether it’s EFI or DI. And some comments about the greater potential for bore scoring between the two fuel delivery modes, based on what is in my car, do I need to give greater attention to bore scoring? I just completed an oil/filter change using Liquid-Moly 5W-40 Leichtlauf Hi-Tec and Mahle filter cartridge. I have never needed to add oil between changes, surprisingly, as even the manual states that it is normal for the engine to consume oil. Examination of the used filter cartridge shows no signs of residue, metal or otherwise. And for the first time, I am sending out a sample to Blackstone Labs for analysis. Open to comments on my oil selection and answers on my fuel delivery system and risk of bore scoring. Thanks, all.

Your 2.7 is EFI. If I were in your shoes, I'd be using Driven DT40. But that's just my opinion, I could be wrong.

Yup. That's what "they say". The report will tell the tale though.

Really? I had never heard that... it's the S-motors (3.x L) that have had issues... 2.9 (what I have) doesn't have this issue, so I'd expect the 2.7L to be fine as well. Do you have a source on the 2.7 bore score issue?

@schwinn https://re*****t.com/forums/987-forum/955517-987-1-cayman-2-7-bore-scoring-prevalence.html I guess I misread what I thought I was reading. LN Engineering says they've never seen in in the 2.7, so I apologize.

No problem, thanks for the update and honesty!

Our base cars (EFI) are less prone to bore scoring due to a bunch of factors, I believe including fuel injection spray angle, etc. "S" versions have DFI, which is where things get a little more difficult. It also has to do with the alloys used, so there's a higher risk in the 2006-2008 models. After doing more reading, I'm still fairly certain that I'm going to give the Driven DI-40 a go in my 991.1S engine in the 981 Outlaw, although it's probably overkill. However, I'm still on the fence about the DT-40 for my 2.9L as I'm guessing it's overkill as previously mentioned. Either way, I'm going to go to 5W-40 and am curious to see if the ticking (2.9L) post-start is quieter. The key thing about the Drive oils is that they have the additives already included -- no need to add it separately. Both oils are very expensive, but we'll see when spring comes. Oil manufacturers don't put in a ton, as they can mess with one's emissions/cats, etc. I don't believe I'm due for an oil change in the 981 (Blackstone directly recommended to me that I go by mileage and not by age), but surprisingly enough I'm close with the 987.2 . TBH, as I drive the 987.2 year round, it's more of a question if I'm ever going to drive it below -10ºF. In my case, that's actually a possibility -- albeit slim. Meanwhile, I think the 5W-40 will have its benefits overall.