2011 Q5 2.0TFSI - Castrol SLX Prof. LL03 5W30

[dbrowne1]

Vehicle has 15K miles. Majority of its use is a daily highway commute of about 18 miles each way, along with some suburban use.

TBN of this oil starts at 5.8 according to a VOA done by another member here recently, which is typical of VW 504/507 oils. Also, there may be a little M1 ESP 5W30 in there from the last OCI, as I used a extractor on the last change and switched over to this oil.

My impressions:

1. Wear metals look excellent for a new engine.
2. I have no idea where the potassium and sodium are coming from, and apparently neither does Blackstone, unless it's just residue from something used in the build.
3. TBN is low but not that bad when you consider it starts at 5.8.
4. TAN > TBN although Blackstone seems to think it's fine.

 

[dparm]

Potassium and sodium shouldn't be left over from break-in. A temporary "spike" in those compounds isn't anything to panic over. See if the numbers come down next time around.

Any reason you chose this oil? Was it part of the included no-cost maintenance?

 

[dbrowne1]

VOA of same oil for comparison

 

[Brons2]

Potassium is a common find in new VW-group engines, ignore it unless you see other signs of coolant contamination.

Good report.

 

[dbrowne1]

Originally Posted By: dparm
Potassium and sodium shouldn't be left over from break-in. A temporary "spike" in those compounds isn't anything to panic over. See if the numbers come down next time around.

Any reason you chose this oil? Was it part of the included no-cost maintenance?


The VOA shows it starts of with 6ppm of Potassium, so I'm not worried about it anyway.

I wanted to use a 504 oil for intake valve deposit control purposes. It is the most accessible 504 oil for me and no different in price than others, and also the most defensible for warranty purposes given the label on the bottle that says it's designed specifically for 2007+ VAG cars.

I had the UOA done primarily out of concern for the boogieman that is U.S. gasoline, with its ethanol and sulphur, and the possibility that a 504 oil would not withstand it given the lower starting TBN.