My CDI Oil Analysis
 

Just for fun I did an oil analysis on my CDI...it is attached. Using Mobil 1 5w40 Turbo Diesel Truck, so I sampled fairly early, at 6200 miles.

Here are the comments from the tech: "Not a bad sample at all. Mild caution on Oxidation and Nitration. Oxidation is typically increased form the presence of moisture, heat, and oxygen. Very normal for diesels. Nitration is the formation of nitric acid initiated by the combustion process, from the fuel being burned. Both of these test are high level tests and typically not performed by many labs, BUT they are crucial when testing to determine extending drains. Your values are low and would not be condemned until they reach the 25-30 range. No worries.

"On your drain interval, I recommend you go with even 10,000 intervals. It is easy to keep track of on the odometer, and the oil will easily achieve this, but also give you great peace of mind that you are getting good lubricant value but not over-extending your drains."

I don't see any reporting of the TBN (Total base number) which measures a lubricant's alkaline reserve, or ability to neutralize acid.
I think if that number is higher than 8, your in great shape when you do a 10K drain.

Speaking of the 10K drain, I am going to assume your TBN great. By looking a the low wear metals count (Iron count is awesome BTW), lots of additive life left, viscosity level looking awesome, and even the concern of Oxidation and Nitration (which looks normal to me), I would think you would have plenty of life left on a 12k drain interval. Retest at that interval if you wanted for peace of mind. But if it were me, I would do 12K easily.



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I am lost. Are you saying that you only do an oil change every 10-12K miles? They only cost about $30 in Atlanta so you save say $30, maybe $60 per year.

And Havoline Express wants me to change the oil every 3K miles.

I was under the impression Mobil1 5/40 truck turbo diesel does not meet the 229.5 spec the CDI owners manual calls for.

Normal Mobil1 0/40 does meet the 229.5 spec.

Either way, good information, I'd been running about 7,000-8,000 miles in my CDI also using Mobil1 products.

If you have someone who will do a fully synthetic oil change on a CDI for $30 it might actually be worth me driving to Hotlanta for an oil change. 2 jugs of Mobil1 from Wally World and a dealer filter runs me close to $65-70 alone and that's for a DIY oil change.

Depends on the car and the oil you use.

For example. Newer cars like shertex's 2006 CDI, could go 20K on synthetic motor oil if oil analysis allows which I have seen.

My newer cars I do easily 10-12K on synthetics.

My w123 using conventional motor oil, I do 5,000-6,000 mile oil changes. But if I was using a synthetic oil and not burning waste veggie, I would do a 8-10K oil changes with an oil analysis once to check.

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Well that is interesting.

No, not synthetics. I was thinking about a conventional oil change for my Lexus and my 81 300SD. Every 5K miles and dino oil. About $30 with filter.

Back a couple of years ago, Autozone had an insane sale on M1 TDT: 12.99 a gallon. So I bought like 45 gallons...my wife thought I was crazy.

When I bought the CDI last fall, I did a fair amount of research regarding the suitability of TDT for the CDI. While it doesn't meet the 229.5 spec, it does meet 228.5, which, from everything I've read, appears to be a more demanding standard. So I think I should be in pretty good shape. This thread comparing 228.x to 229.x was one item I came across: http://www.peachparts.com/shopforum/diesel-discussion/88390-fyi-mb228-x-vs-229-x.html.

FWIW the PO used Shell Rotella T6, which also does not meet 229.5. But he did 3k drain intervals, so I'm pretty confident the engine was well cared for over its first 146k miles.

Something to remember about oil analysis, the metals content portion is more for an early warning that something is coming apart than a "your oil is still good" indicator.

Engines with good fuel control allow for longer oil change intervals. Changing modern oil every 3 K is excessive for a car with even decent fuel control. However a car with a carburetor / really poor diesel injection / piston ring wear probably isn't going to benefit from synthetic since the oil will become contaminated before it wears out.

In theory, a car with a 10 QT oil pan could run 2X between changes over a 5 QT system further making over frequent oil changes unnecessary.

"does not meet the 229.5 spec" is a bit of a sticky wicket ... failed or wasn't tested? I am looking at an upcoming oil change and the July 2016 version of 229.3 list for a gassers .... and it does not show Mobil 1 15-50 which I really want to try. Mobil one has what seems to be the longest list of approved various oils of anyone, but that one is absent. Is it failed or not tested? Wish I could find out. In the other hand, I go few miles between changes anyway so it would be surprising if an oil 30 years into the future from the engines production date wasn't somehow good enough. :D

Depending on the year of your Lexus, Toyota/Lexus changed the oil change interval to 10,000 miles with synthetic oil.


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Better Fuel control use introduced in Europe much earlier than in the US, as a result they were doing extended earlier too. The average oil change interval now in Europe is 30,000 km. Basically, it's 18,000 mile oil change intervals.

As far as metal wear is concerned. Everyone should read these posts from a respected TDIClub member and fuel injection specialist about a little known subject of how the modern motor oil functions.

First post.

TDIClub Forums - View Single Post - Final Horrifyingly Stupid Question - OCI?

Second post.

TDIClub Forums - View Single Post - 10,000 miles...really??


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That's a killer deal on M1 TDT!

3k drain intervals on a motor as modern as the 648 is an incredible waste of oil but its good for you the next owner of the car.

It is actually my understanding that the 229.5 spec is more for the emissions system of the modern engines. The 229.51 spec for the bluetecs (or like VWs 507.00) is all about protecting the DPF. Using a non 229.5 oil you're not, not protecting the engine, but you may be damaging the Catalyst or clogging up your EGR cooler faster. But that's just my speculation, I suppose I'm basing that on no real data. In my world I don't have 40 gallons of M1 TDT on the shelf, nd the 0/40 Mobil1 229.5 oil is the same price as all the other oils (might actually be cheaper since it comes in 5.1qt jugs) I have just always run that in my CDI.

I'm in no way saying M1 TDT is a bad oil, and I understand the anti-wear additive aspect of a 228.x spec oil, but with modern emissions controls and filters, that is not the whole picture. A 228.x oil would be a killer oil in say a W123, but it could also very easily roach the DPF in a Bluetec car, which the DPF alone is worth more than most of our 123s. So it worth thinking about. 648s don't have DPFs, so this all may very well be a moot point.

Regularly changed Mobil Delvac conventional oil would probably "protect" the engine itself just the same if it was changed at the right intervals.

Just food for thought, I appreciate you posting your oil results, good to hear the 10,000 mile intervals on a quality oil in the OM648 are well within the realm of reason.

I appreciate the input. Having a bit of trouble remembering all the details of the research I did...but, if I recall correctly, there were no downsides to using TDT in a CDI, even when considering the emissions related stuff. But, if that's not the case, I'd be happy to switch to a 229.5 oil, my huge stash of TDT notwithstanding. And obviously, if it were not for the stash, I'd be using a 229.5 since, as you say, the cost is roughly the same.

DieselPaul...FWIW I ran your questions by my oil analysis tech. His reply, in part: "No worries on after treatment devices as this product is CJ4 spec which identifies that it has a non-metallic ash content and therefore is designed for EGR and SCR systems. It is true that pre-CJ4 oils contained higher levels of zinc and phosphorus which will poison a catalyst, but even then it may last nearly the lifetime of the vehicle."