Don't know if I posted that, but it is the prevailing theory. Given that other VAG vehicles use the same engine with a higher OCI I don't know if that is the full story though.

The reasonable side of me says that it may be that coupled with an expectation of Porsche owners driving harder. The cynical side says its just so they can get more service money.

 

they told me to bring my own filter, because they don't know if its different or not, but that was about it.

 

I assume they were able to reset the computer for the next scheduled maintenance, right?

 

haven't been in yet, but I would think they can.

 

If it was truly a matter of service money, they'd write the warranty to classify other-than-dealer oil changes as a violation. And driving a diesel hard actually keeps it cleaner. The issue is with diesel soot. Soot is a byproduct of partially burnt diesel fuel. It's what turns the engine oil black. The C30 oil is formulated to help keep that soot in suspension. Otherwise it would sink to the bottom of the pan and form sludge. My theory is that the our low cetane fuel is forming more sludge than Porsche expected. Hence drain hot oil every 5k, to minimize sludge accumulation.

So fast driving maintains temperatures that are not soot-friendly, and I don't doubt that the fuel burn is more complete as well. It may be why this is the only diesel engine I've seen that operates at 95 degrees Centigrade. All my previous diesels have had thermostats ranging between 70C and 85C. And it also may explain why the owner manual does not recommend warming up the engine before driving. It's pretty evident that they just want you to start and go. Slow/sluggish driving and cool engine temperatures accelerates soot accumulation.

//greg//

 

Except that would be illegal for them to do/enforce in the US. Even without a requirement they know that most people will take their cars (for any brand) back to the dealer for service intervals anyway though. I don't think anyone can look at what dealers are charging for an OCI and not see that there is a significant profit being made from them.

I'm not saying that really has anything to do with the lower OCI, just that my cynical side would believe it

If soot/sludge was really a problem, wouldn't the other cooler engines have more problems with this and wouldn't the other MFGs change the OCIs accordingly? Especially the VAG brands which have the same engine?

I'm sure Porsche has some good technical reasons for it, but they haven't said and I don't think the simpler answers add up.

 

I've owned 10 diesels over the years, the most recent a 2011 Touareg. None of those vehicles were of the "clean diesel" design. Pretty sure that didn't get introduced until MY2013. Can't speak for other diesel manufacturers, as I don't know anything about their individual clean diesel designs. Admittedly, the 2013 Touareg TDI is the same basic clean diesel design. So the difference in the OCI may be as simple as the difference between a VW-tuned engine and a Porsche-tuned engine. That said, would you be surprised if VW decided to lower their OCI as well?

Regardless of manufacturer, additional heat is necessary to the particulate removal process. But it seems that the current Porsche DPF/DEF design is a double-edged sword; while lowering emissions and eliminating dirty tail pipes, it seemingly aggravates the soot problem

//greg//

 

Your 2011 Touareg should have been of the same clean diesel design. Same DPF and adblue injection.

 

Not at all. In fact if there is good sound reasoning for why Porsche has done it then I would expect VW and Audi to do it as well.

 

Nope. Same block perhaps, but not the same engine. My 2011 VW had the 225hp CATA engine, the 2013 Porsche (new designation unknown) engine has 240hp. Don't know about internals, but - among the visual differences - the CD engine has more heat shielding, different turbo, different turbo location, relocated oil fill neck, relocated oil filter. Plus the VW had over 17,000 miles on it when I traded, yet I have absolutely no recollection of an AdBlue system. That said, perhaps my 15 months of Touareg ownership was just one extended senior moment.

//greg//

 

If the diesels are meant to be driven a little harder to keep the engine temps up, does that mean a lot of miles in traffic conditions may ultimately be detrimental to the engines longevity?

 

I doubt it. In the old days you'd just take a diesel up on the freeway and "blow'em out"; that is, run it in a lower gear so you can redline the engine for a mile or so - or at least until you don't see black smoke in the mirrors anymore. Not so with these newer diesels, that's done with the particulate removal system. That by itself requires heat, more than can come from the exhaust alone. When highway driving alone can't keep the DPF clean, a mixture of diesel fuel and DEF is injected by the computer to burn the filter clean. That necessarily adds to fuel consumption as well.

//greg//

 

Must have been. See post 3.

http://forums.tdiclub.com/showthread.php?t=323830

(P.S., I searched for 2011 Touareg TDI DEF and this was one of the first hits. I didn't seek out one with you in it!).

 

You're right , definitely a senior moment. The subsequent 16k miles/14.5 months of ownership with no AdBlue events definitely scrubbed memory. That said, the VW spare was an 18" donut. The 18" collapsible in the Porsche affords me a constant visual reminder that there's a n AdBlue fill cap under there

 

Better than no spare and goofy RFT's in my BMW.

Does the Porsche spare have a goo can or a compressor?