A New LSPI Test for Aged Oil

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Different combinations of detergents were compared in LSPI testing, new and for used oil over the duration of the OCI. They found the Ca + Mg to be the best. High moly negates it initially, but over time it goes up a bit. Results are on page 36.

How common is LSPI? I don't know of anyone personally that has had this issue.

Page 32
 
Nice paper, buster!

Of course, it's been well known that calcium is the main culprit behind low-speed preignition (LSPI).

However, it is interesting to know that moly and titanium help in new, fresh oil, but they don't help much in used oil.

I guess they didn't study ZDDP because of the phosphorus limitation, but I doubt high ZDDP can save you from LSPI caused by high calcium either.

Moreover, I think having a well-balanced mixed calcium and magnesium detergent may help reduce wear and extend oil life over a calcium-only detergent; therefore, I think it is a win-win.

What I find interesting is that ACEA and Euro OEM's are now playing catch-up against the API/ILSAC and US OEM's. They are yet to introduce the ACEA A6/B6 (thin xW-30) and C6 (xW-20), and their thick-oil categories such as A3/B4 and C3 will remain without LSPI protection in the unforeseeable future, also meaning their thick-oil categories may go extinct even faster as they are not keeping up with the technological advancements. The one-size-fits-all approach of API/ILSAC helped them take a giant step forward without procrastinating like ACEA and Euro OEM's are doing. Whether LSPI is rare or not is somewhat a moot issue. It will be more common as higher-BMEP engines are introduced, which is certainly what is happening to meet the newest fuel-economy standards.
 
LSPI is more problematic in small TURBO engines...right?
While I would guess that calcium raises the SA level of an oil...has it been fully established that higher calcium leads to IVD's?

Some of us have DI's without turbos and are interested to know if our pre-SN+...pre-D2G2 syns. cause IVD's. I have several quarts
of original PU, PP, QSTP etc that are SN (even some SM) and I'm not sure about using them in my DI vehicle?
 
Judging from the graph of LSPI events for each of the test runs, it is statistically rare. I don't know how long the test cycle is, but it must have hundreds of thousands of combustion events, and the maximum number of LSPI occurrences was 30 in one of the reference runs. The test oil with the Ca+Mg additive package performed best with fewer than 5 LSPI's for both the new and aged oils. The Mo and Ti fortified oils were formulated with concentrations much greater than current oils.

lspi-graph.PNG
 
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Maybe Amsoil achieved a 100% LSPI score due to the Ca + Mg + 250ppm of Moly?
 
Originally Posted by Gokhan
Nice paper, buster!
.

What I find interesting is that ACEA and Euro OEM's are now playing catch-up against the API/ILSAC and US OEM's. They are yet to introduce the ACEA A6/B6 (thin xW-30) and C6 (xW-20), and their thick-oil categories such as A3/B4 and C3 will remain without LSPI protection in the unforeseeable future, also meaning their thick-oil categories may go extinct even faster as they are not keeping up with the technological advancements. The one-size-fits-all approach of API/ILSAC helped them take a giant step forward without procrastinating like ACEA and Euro OEM's are doing. .


Go to VOA/UOA section of that forum...and look @ EU ACEA Cx oils in particular....vast majority of them will look like that test sample with a "reduced Ca + Mg" formula...

And dont forget that oil is not the only "precaution" you can take.....its also combustion chamber design...how many injections per cycle you have....or if that doesnt help....you can also add additional injector to the cylinder (MPI + GDI)
 
Originally Posted by Kamele0N
Go to VOA/UOA section of that forum...and look @ EU ACEA Cx oils in particular....vast majority of them will look like that test sample with a "reduced Ca + Mg" formula...

And dont forget that oil is not the only "precaution" you can take.....its also combustion chamber design...how many injections per cycle you have....or if that doesnt help....you can also add additional injector to the cylinder (MPI + GDI)

Are they reformulating them for SN PLUS and SP? That's a good thing if that's the case.

The engine makers know about the LSPI design challenges—there is a lot more to it than what you said. I have a review article about LSPI here.

Review article on low-speed preignition (LSPI) and super knock
 
I would have liked to have seen a higher ZDP formulation in the mix in this study, but due to the limitations I'm not surprised. Ca + Mg seems to be the winning combination new, and used.
 
I just saw this and almost posted it again. Thanks to @wwillson and crew for the new feature that pops up to show you similar postings.

What an interesting read! Dynamics of this issue i never considered...

*How aged oil relates to LSPI.
*Low Calcium with higher Magnesium versus high Moly and Titanium.
*That the new test cost $350k.
*That the API never funds these tests but made financial contributions here.
 
I just saw this and almost posted it again. Thanks to @wwillson and crew for the new feature that pops up to show you similar postings.

What an interesting read! Dynamics of this issue i never considered...

*How aged oil relates to LSPI.
*Low Calcium with higher Magnesium versus high Moly and Titanium.
*That the new test cost $350k.
*That the API never funds these tests but made financial contributions here.
What is interesting some M1oils have had the low Calcium and higher Magnesium oils for quite a while.
 
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