Let's Talk...Oxidation

Status
Not open for further replies.
Joined
Sep 26, 2010
Messages
9,791
With my most recent OC in my GLC, I switched to Castrol Edge European in 0W-40. In some ways, I am glad that I did, though I will not know for a while if it is better than M1 Euro 0W-40 in any way. M1 has me concerned because MB has a 10K OCI, however here are the oxidation rates for the past 3 OCs:

YaLsU4.jpg


* - nearly certain the dealer used xW-30 as the FF instead of the required xW-40. The viscosity was flagged as low, but the lab was expecting an xW-40 as I indicated.

They flagged the oxidation level of 24 as "caution" and the oxidation level of 34 as "warning" and requested that I send in a VOA to set a baseline. Obviously, (and depending on the next UOA), I will either continue with Castrol or I will try Pennzoil Platinum Euro 0W-40 to see how it fares.

What is the general opinion of the oxidation readings? It is my belief that I would have had a much higher reading had I gone the full 10K, though otherwise, the oil seems to be fine.

What say you?
 
To me oxidation is the not so evil twin of shearing. It counterbalances the viscosity break down, which is why you will see dips and rises as you follow multiple samples of the same fill.
That's how I understand it, will gladly be educated if I'm wrong.
 
Originally Posted By: SOHCman
Time to change your own oil if you cant trust the dealer
I do change my own oil--the dealer wants $300 which is nothing short of a joke. Unfortunately, unless you dump the factory oil the moment you drive a new car off the lot, you tend to trust the dealer. Obviously, although Draper of Salt Lake City sells AMG, they are fairly clueless about the oil they require.
 
Virgin M1 0W-40 oxidation values I’ve seen were well above zero, like in the 20s or 30s, from what I recall. This one had it at 37.5. It is almost certainly that high due to a minor amount of ester base oil(s).
http://www.oil-club.ru/forum/uploads/monthly_08_2017/post-2-0-09076400-1503630107.jpg

What matters is how much it increases from the virgin oil’s value. I would look at all of the data, including the increase in oxidation, to determine when the oil is to be condemned. I personally get concerned when the oxidation increases by the high teens to low 20s. I err on then side of caution while others push the oils farther and take a larger risk.
 
*”..... - nearly certain the dealer used xW-30 as the FF instead of the required xW-40. The viscosity was flagged as low, but the lab was expecting an xW-40 as I indicated.....”


Do you mean with which grade the dealer used on the first oil change?
 
Originally Posted By: PimTac
*”..... - nearly certain the dealer used xW-30 as the FF instead of the required xW-40. The viscosity was flagged as low, but the lab was expecting an xW-40 as I indicated.....”

Do you mean with which grade the dealer used on the first oil change?
No, I mean the oil they filled it with on the make ready as in the factory oil (original oil). It was clearly a xW-30 based on the viscosity. AMG vehicles require a xW-40 which makes me even happier that I dumped the factory fill early.
 
Originally Posted By: JAG
Virgin M1 0W-40 oxidation values I’ve seen were well above zero, like in the 20s or 30s, from what I recall. This one had it at 37.5. It is almost certainly that high due to a minor amount of ester base oil(s).
http://www.oil-club.ru/forum/uploads/monthly_08_2017/post-2-0-09076400-1503630107.jpg

What matters is how much it increases from the virgin oil’s value. I would look at all of the data, including the increase in oxidation, to determine when the oil is to be condemned. I personally get concerned when the oxidation increases by the high teens to low 20s. I err on then side of caution while others push the oils farther and take a larger risk.
I may send in a VOA at some point, but I have a stash of Castrol and Pennzoil 0W-40 to go through before switching back to M1 (if I ever do).
 
Originally Posted By: 2015_PSD
Originally Posted By: PimTac
*”..... - nearly certain the dealer used xW-30 as the FF instead of the required xW-40. The viscosity was flagged as low, but the lab was expecting an xW-40 as I indicated.....”

Do you mean with which grade the dealer used on the first oil change?
No, I mean the oil they filled it with on the make ready as in the factory oil (original oil). It was clearly a xW-30 based on the viscosity. AMG vehicles require a xW-40 which makes me even happier that I dumped the factory fill early.


I have never seen a new CAR (or truck) shipped dry. Motorcycles / ATVs / lawn mowers yes - things that are crated, but cars and trucks no. If someone can verify that AMG are shipped dry and filled by the dealer I’d love to hear it, but suspect that it was filled with whatever Mercedes / AMG Filled it with.

As for the oxidation numbers I would say its difficult to draw any conclusions in absence of an idea what the virgin number is...
 
Originally Posted By: DuckRyder
I have never seen a new CAR (or truck) shipped dry. Motorcycles / ATVs / lawn mowers yes - things that are crated, but cars and trucks no. If someone can verify that AMG are shipped dry and filled by the dealer I’d love to hear it, but suspect that it was filled with whatever Mercedes / AMG Filled it with.
In either event, someone screwed up royally--there is no way that M1 0W-40 (which is what should have been in there since MB "recommends" M1 and AMG requires xW-40) sheared down to a very light xW-30 in only 1,600 miles. This is especially true since it has not happened on my runs of M1 0W-40 with triple those miles.
 
Syn oils show oxidation readings when brand new. Not that I know what it means..
 
Recently had an oxidation value of 91 in a 6.7L F250 PSD. Last OCI, using same oil, oxidation value was 4. Never had high oxidation value before in this engine.

Any thoughts on what could be the cause of such a high oxidation value?
 
Originally Posted by Garak
Same lab, too?


Same lab (polaris/oil analyzers). Redline 15w40 same oil. 7200 miles on oil. Fuel dilutuon 4.3%. TBN 3.9.
Wear numbers were ok. Oil was starting to thicken a bit more than usual, presumably due to oxidation.
 
Last edited:
Hmm. Same oil, and no reformulation in between? It is kind of odd, but not out to lunch. What's the VOA oxidation value on the product? If I recall correctly, it's high to start. If anything, I'd suggest that an oxidation number of Red Line on an analysis of 4 would be suspiciously low. Every Red Line analysis I've seen with oxidation done is high, even on VOAs. Now, there is always lab variance, but I'd suspect 91 is normal for Red Line. If you sent in some unused Red Line for a VOA, I'd wager the nitration would be up in that neighbourhood already.
 
Originally Posted by Garak
Hmm. Same oil, and no reformulation in between? It is kind of odd, but not out to lunch. What's the VOA oxidation value on the product? If I recall correctly, it's high to start. If anything, I'd suggest that an oxidation number of Red Line on an analysis of 4 would be suspiciously low. Every Red Line analysis I've seen with oxidation done is high, even on VOAs. Now, there is always lab variance, but I'd suspect 91 is normal for Red Line. If you sent in some unused Red Line for a VOA, I'd wager the nitration would be up in that neighbourhood already.


Just posted the UOA in the HDEO UOA section. Combination of increased oxidation, increased viscosity, and increased fuel dilution has me confused!
 
Last edited:
Status
Not open for further replies.
Back
Top