Testing different oils one after the other...

[flatlander757]

So I do 5k intervals on my DD/autocross car.

I'm interested in trying some different oils to see how wear numbers trend, both different brands and different weights.


Would it be not worth my time(er money more like it) to do them every change with a different oil? Or would it be a good idea to do 5k on the "next" oil to be tested with no UOA, then run same (new) stuff a second 5k THEN do a UOA?


I'm curious about Mobil/Castrol 0w20, Mobiland Castrol 0w30, and Mobil 0w40 primarily. Also Pennzoil Platinum 5w30... All vs the 0w20 PP I run now in my 2011 Mazda2.

 

[Toaster_Jer]

In my xB I am running 0w-30 M1 for 5 and will compare it to the 5w-30 the next 5. Down the road I may run it against the 5w-30 QS ultimate durability. You may want to test the Amsoil signature series 0w-30 cause in the 02' Prius, runs great and Blackstone says to push it to 13,000 mi. Have fun learning!

 

[Fsharp]

You can see in some of the other UOAs posted on here that some of the additives "carry over" into the new, different oil. Also, I've heard somewhere that when you change oils, slightly more wear may occur over the next OCI due to the different additives clashing. For these reasons I'd hold off on the UOA until the second OCI of a given oil.

 

[Garak]

From a perspective of comparing oils, this will amount to a waste of money and a bunch of hogwash. Comparing one UOA to another to somehow compare oils isn't going to work. You might be able to get some information as to which oil will last longer in service, with a bit of trending. You might be able to discern the same about shearing.

Comparing "wear" by comparing individual UOAs is, however, simply nonsense.

 

[Eddie]

In addition; one different oil after other never permits the "New" oil to wear in. It takes two or even three oil changes to establish the "new" oil values. Ed

 

[HerrStig]

Originally Posted By: Eddie
In addition; one different oil after other never permits the "New" oil to wear in. It takes two or even three oil changes to establish the "new" oil values. Ed
What's an "oil value"?

 

[Toaster_Jer]

I wonder about these points too. Blackstone says to perform 2 or3 to develop a trend. Some say these additives can clash(I was told that personally) others say they are all compatible. Now the new Dexos1 is causing many to change their ad pack that will possibly obscure UOA. Changing to a new formulation or brand might affect the iron,aluminum and sodium for instance but yeah, I'm lookin at the TBN and how stable the oil is. If I make a change I am doing it because I hope it's a better oil for that motor and my driving habits.

 

[Kuato]

Originally Posted By: flatlander757
So I do 5k intervals on my DD/autocross car.

I'm interested in trying some different oils to see how wear numbers trend, both different brands and different weights.


Would it be not worth my time(er money more like it) to do them every change with a different oil? Or would it be a good idea to do 5k on the "next" oil to be tested with no UOA, then run same (new) stuff a second 5k THEN do a UOA?


I'm curious about Mobil/Castrol 0w20, Mobiland Castrol 0w30, and Mobil 0w40 primarily. Also Pennzoil Platinum 5w30... All vs the 0w20 PP I run now in my 2011 Mazda2.


Depends on how long you want to take for the test....but IMO if you let it drain sufficiently you'll get a fair representation each time; the small amount of oil left over shouldn't make much difference.

 

[Garak]

It's still a silly way to determine which oil is performing better in an engine. It's a great way to find out if the lubricant is suitable for continued use, though.

 

[flatlander757]

Yeah I understand a lot of it will be just noise in the grand scheme of things, I'm not looking for a magical super-oil... Moreso just curious in general. Stuff that does "well" will likely get more OCIs done with UOAs.

I think I'll try to start doing UOAs every other change mainly to save money, and compare some different oils in general mainly for grins.

 

[Shannow]

Pertinent to the discussion is what Castrol did when they were developing Magnatec in Oz. Had a dinner back in my turbine days and sat next to a chemist who worked on the programme.

They had test engines.

Test engine did
Reference Oil - Mobil 1 (5 or 15W my memory is not sure of) 50
Flushing oil - a standard ish oil (say like an SAE30)
Test oil - Magnatec
Flushing oil
Reference oil (again M1).

The deal was that the engine condition changed over the test, and the two reference oil runs were to "bookend" the changes in performance that were not attributable to the oil change per se.

The flushing oil was to remove as much cross mixing between the reference and the test (the magnatec, he stated left enough surface chemistry to affect the second flush AND the bookend).

That's how Castrol approached comparing different oils, and I'm not sure on the specific tests that they did.

The takeaway to me was that changes in the engine as the tests went on were pertinent and needed to be checked at the end.

Trending UOAs over multiple OCIs over the life of an engine
a) takes a really long time, Blackstone's advice to do multiple runs on the same oil is proper (and makes them some money while adding to their database)
b) really doesn't measure the things that you are trying to determine (wear)...sometimes doesn't even predict catastrophic failure.
c) doesn't have the "same engine" in run 6 as run 1.