'03 VW TDI, Mobil Delvac 1 5W-40, 40k on vehicle, 10,481 on oil.

[pezzy669]

This is my second oil analysis for my Golf. I went from Rotella T 5W-40 (which has only been in my car for one run) back to Delvac 1 5W-40. I changed the fuel filter and air filter about 7500 miles into this run.

The oil was in use 10,481 miles, about 3 months of service (July - Oct). About 60% highway/40% city, powerservice silver was used on about 75% of the miles and mostly BP/Amoco "Premium" or Gate diesel was used. No makeup oil was added however car was about 1/2-3/4 quart low after at the end of the run.

The first column is my 30k analysis, second is the 40k analysis (which has 10,481 vs. 9814 miles ont he oil).

Aluminum - 3/4
Chromium - 2/2
Iron - 24/24
Copper - 3/3
Lead - 2/3
Tin - 0/1
Moly - 1/1
Nickel - 1/0
Manganese - 1/1
Silver - 0/0
Titanium - 0/0
Potassium - 0/0
Boron - 1/18
Silicon - 3/5
Sodium - 2/2
Calcium - 3509/2815
Magnesium - 116/462
Phosphorus - 980/1101
Zinc - 1154/1386
Barium - 0/0

TBN - 6.2/6.6

Sus Visc @ 210F
Should be - 64-76/66-78
Tested at - 73.6/78.0

Flashpoint
Should be - >410/>415
Tested at - 455F/455F

Fuel - .5%/.5%
Water - 0/0
Insolubles - .3%/.4%
Antifreeze - 0/0

Blackstone comments:

Adam: You are inching up your oil use interval and wear is showing no changes, a good sign you have not reached your limits. As well as the engine is doing we suggest continuing to increase the oil use interval. The oil was still in good shape. The viscosity was normal for a 5W/40. No fuel dilution, moisture or anti-freeze was found. Insoluables were ok at 0.4% showing good oil filtration. The TBN was strong at 6.6, so the oil still had some life left. This is a different type oil, which is why the TBN increased after more miles use. At 40,451 miles, no problems found.

Thanks guys for your comments.

 

[jthorner]

It looks to me like the extra money spent on Delvac-1 over Rotella T syn didn't buy you anything.

John

 

[JohnBrowning]

I say it looks good. More miles and an air filter change mid way through. The differences are insignificant. Normaly if you change air elements dureing an OCI you get a large spike in wear metals due to contamination.

 

[pathpower2]

This just shows that additive package is more important than the chemistry of base oil (if you forget about the bad group 1 of course).

A saw a number of truck UOAs where there were no differences whatsoever between dino (15W40) or synth (5W40) HDEOs. I bet you would get same wear metals with any 15W40 HDEO. Maybe worse MPG though.

 

[JohnBrowning]

I do not think that two UOA can really tel us a lot just yet. It did tell us that each 5W40 HDEO held up fine for the specific OCI it was used in. We would need more data to realy see a trend. I think that it is safe to say that in each OCI the oils clearly had plenty more rexerve capacity. I belive that as he push's the interval out farther like to the 12,000-18,000 mile OCI we will see a bigger difference in how each oil performs. 10,000 miles on a "Synthetic" diesel oil is really not much of a test! M1 and Amsoil have been tested out to around 18,000 miles in a gasser with little difference between the two.

 

[Arup]

The other factor to add would be extreme conditions such as overload, extended high speed runs, extreme heat or cold, I am positive that in these situations, the synthetic oil would hold up much better, for day to day ordinary conditions regular HDEO should serve nicely.

 

[TexasTDI]

I'm surprised to see the TBN so low after only 10k miles. I would have expected it to be around 8.

 

[TexasTDI]

I've now seen two 10k mile UOA's using Mobil Delvac-1 with a TBN of only 6. Guess D1 isn't as good an oil as we would like to think it is. Especially considering my 10k mile UOA's have been at or above 8 using Amsoil 15w-40 and Amsoil 5w-40.

 

[Arup]

Strange that the UOA of Delvac Super/MX as well as Delo 400 fares much better than D-1.