Spicy

For those of you who are deleted, or experienced with - what oil are you using and what are you oil change intervals? I put down a bunch of highway miles, 4k+ a month, I am looking to stretch intervals as long as possible without sacrificing my engine, turbo, etc.

reneeweiss

Porsche recommends 5k but some Audis are 10k- not sure why there is a difference since I think it is the same motor. Toureg may be 10k also but I don't know.

AnAlbumCover

I don't have a turbo diesel but the general consensus is that quality of oil will make a bigger difference than intervals.

I have the NA 4.8 V8 and do 5k mile 0w40 OCIs but really I could probably get away with 10k. On a turbo'd motor a lot of the heat from the turbo is transferred into the oil so something with a good shear properties is needed. I think any sooner than 5k is a waste of money. 10k may be too far. If you're romping on it on the highway a lot I'd do 5k OCI, otherwise 7-10k is probably fine.

lml999

@Spicy Why guess? Get your oil analyzed by Blackstone or similar and they will tell you, based on the results, how often you should change your oil.

pyramidimaging

During an oil change the drain seal didn't hold back the oil and they had to replace the seal. The engine had only run for about 15 minutes and never let the repair shop. I was amazed at how dark the brand new oil looked when they had to flush it back out. The shop owner said that is the way it is with diesel. My porsche mechanic back home told me the same thing.

So, if it gets that dark after 15min then I'm thinking it needs to be changed fairly frequently. I think you'll know if you waited to long when the engine oil temperature sensor tells you it's too hot.

lml999

Both statements are simply incorrect.

Diesel engine oil turns dark quickly because its doing its job. (With your logic, you'd be changing oil hourly). It hasn't lost its lubricity. Only an oil test can tell you that.

And...if your temp sensor says that your engine oil is too high, then either you're putting a heavy load on the engine (climbing mountains, towing), your oil pump is gone or something else has gone wrong internally. That's not an oil age issue. It's *way* too late to change the oil at that point.

Spicy

Thanks for the feedback. I will perform a couple of oil change analysis to establish how far I can stretch things.

Suggestions for oil type on a deleted car?

lml999

More important to follow the specific oil spec of your (deleted?) car.

Personally, I was using Shell Rotella T6 until someone pointed out that it doesn't quite conform to the Audi/Porsche diesel spec. I think I'm using Motul now....

...but the spec is most important. Any quality brand oil that meets the spec should be sufficient.

Spicy

I am running T6 in my deleted TDI Jetta, 250k miles and it is still alive. I have not performed an oil analysis in quite a few miles, I might do one just out of curiosity.

In regards to the T6 not meeting spec, I wonder if this is because of emissions equipment requirements or something else?

AnAlbumCover

I don't use T6 anymore but I used to in my Mazdaspeed3 but its great for turbo's and shear strength. I would ignore the fact its not "approved" and use it confidently in any turbo application. The approvals are more marketing than anything else.

schwarz633

My understanding is that the recommended Mobil 1 ESP is low ash, something to do with the DPF.

AnAlbumCover

Probably. But Rotella T6 is a low SAPS oil and is intended for vehicles with a DPF. The most common US industry standard ash spec for such oils seems to be 1.0% (which T6 complies with), but German manufacturers (MB, BMW, VW, etc.) decided 0.8% is better.

I would confidently run T6 if I had a diesel. Its a proven oil that performs well in both diesel and gas engines. IMO, the shear strength is more critical than ash. You'll only get ash in your DPF if oil burns. Oil will burn if it thins out (shears) due to heat or mixing with fuel (bad piston rings). If your rings are still good then an oil with good shear strength should keep oil burning minimal.

BUT, I'm an internet expert so do your own research (google "TDI Rotella T6, Audi Rotella T6, etc.) and use what gives you peace of mind, all the name brand oils are good.

JamesN

When I had my diesel, I used what the owners manual said, C30 Porsche spec , Mobile I ESP. 5000K intervals. My local auto zone usually had 5 quart jugs for around $30-35. Regular Blackstone analysis confirmed the engine was in great shape . I have an oil extractor and could do the oil change in less than 20 minutes, barely had to wash my hands afterwatrds it was so easy.

Jim
2017 CS currently

skiahh

It is the same motor. There has been much speculation on just why Porsche went with 5K intervals vs the 10 of the other brands. The speculation ranges from DEF to tuning, but I don't think I've ever heard a definitive answer.

Bottom line, if you're still in warranty, you have to comply with the 5K interval. Once you are your own warranty, use good oil (I'm still going to keep the C30 spec) and a lab analysis to inform your oil change intervals.

BrewDude

I have been miffed by the 3.0 TDI conundrum on oil changes as well. When I owned my Touareg TDI, intervals were 10k. With the Cayenne diesel it's 5k. It's the same engine but yet why the difference in change intervals for an engine that's built by VAG and utilized across multiple platforms (Audi A6/Q5/Q7 as well)?

So the past two oil changes I've sent to Blackstone for analysis. On the 5k change, they recommended going to 7.5k which I did. On the 7.5k oil change, they recommended going to 10k which I'm currently doing now.

Once I hit the 10k interval, I'll send a sample off for another analysis. Always used Porsche C30 spec oil in different varieties (Mobil1, Motul, Total).