Lubrizol says SN PLUS and GF-6 not enough for LSPI protection in TGDI engines

[Triple_Se7en]

Thanks wemay!

 

[wemay]

Originally Posted by Triple_Se7en

Thanks wemay!

 

[wemay]

If you subscribe to the Infineum theory of Calcium not really playing a part and that GrpII oils are more resistant, many high mileage oils would fall into this camp... 5W-30 used as an example

 

[JAG]

Infineum's statement in the article is: "The effect of calcium and magnesium based detergents on LSPI has already been the subject of Infineum studies. Calcium-based detergents have been shown to strongly promote LSPI while magnesium-based detergents appeared to have nearly no effect on LSPI. However, various calcium and magnesium concentrations have been observed to have no statistically measurable difference in the IQT for gaseous fuel/oil/air auto-ignition." They don't define what the various concentrations were. Since we don't know and the second sentence says calcium strongly promotes LSPI, I think it's not prudent for us to think that we don't need to have much concern about how much calcium is in oils.

 

[wemay]

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

 

[Shannow]

Originally Posted by JAG

Infineum's statement in the article is: "The effect of calcium and magnesium based detergents on LSPI has already been the subject of Infineum studies. Calcium-based detergents have been shown to strongly promote LSPI while magnesium-based detergents appeared to have nearly no effect on LSPI. However, various calcium and magnesium concentrations have been observed to have no statistically measurable difference in the IQT for gaseous fuel/oil/air auto-ignition." They don't define what the various concentrations were. Since we don't know and the second sentence says calcium strongly promotes LSPI, I think it's not prudent for us to think that we don't need to have much concern about how much calcium is in oils.

That's what I was saying earlier...they state that it's a strong correlation in the engine test, but that it doesn't show in their "cetane test" (which is what their test is based on, diesel engine cetane. As a result, I think that their decision to test the cetane (autoignitability) of the oil is a poor proxy for LSPI, and not correct.

Quote

The IQT-measurement, which is based on an ASTM method (D6890), required several repeat tests.

https://www.astm.org/DATABASE.CART/HISTORICAL/D6890-08.htm

Quote

1.1 This automated laboratory test method covers the quantitative determination of the ignition characteristics of conventional diesel fuel oil, oil-sands based fuels, blends of fuel containing biodiesel material, diesel fuel oils containing cetane number improver additives, and is applicable to products typical of ASTM Specification D 975 grades No. 1-D and 2-D regular and low-sulfur diesel fuel oils, European standard EN 590, and Canadian standards CAN/CGSB-3.517 and 3.6-2000. The test method may also be applied to the quantitative determination of the ignition characteristics of diesel fuel blending components. 1.2 This test method measures the ignition delay and utilizes a constant volume combustion chamber with direct fuel injection into heated, compressed air. An equation correlates an ignition delay determination to cetane number by Test Method D 613, resulting in a derived cetane number (DCN). 1.3 This test method covers the ignition delay range from 3.3 to 6.4 ms (61 to 34 DCN). The combustion analyzer can measure shorter and longer ignition delays, but precision may be affected. For these shorter or longer ignition delays the correlation equation for DCN is given in Appendix X2. There is no information about how DCNs outside the 34 to 61 range compare to Test Method D 613 cetane numbers.

You can't claim both * real world and test engine experience shows a strong correlation to Calcium * that our (non engine test) refutes that, being insensitive to Calcium * the findings of our (non engine tests) accurately reflects the effect of basestock on LSPI.

 

[wemay]

Thanks Shannow. I guess it's best to ignore this testing method. I always prefer real world approaches to bench tests where possible. Besides, Chevron Ornite, SAE and various others have already concluded, after years of study, the Calcium correlation is valid. My question is why would Infineum take this approach after they too have concluded this in the past?

 

[dailydriver]

Originally Posted by wemay

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

Maybe Motul, and Red Line should 'build' an oil with a reduced calcium/sodium, but with even higher POE content than anything they produce currently, with large amounts of 'trimer' moly in them? [dunno]

 

[Garak]

Originally Posted by Gokhan

LSPI happens in TGDI engines but it's caused by the oil. Therefore, it's possible to prevent it by changing the oil chemistry.

In reference to other points in the thread, particularly about Europe, is it really that simple? Engine tuning and shift points, I would suspect, make a big difference. What happens when people operate some of the supposedly susceptible engines with an auto in sport mode or with a manual kept at a higher RPM range?

 

[BLND1]

Originally Posted by wemay

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

Could this be why Mobil is pushing group II+ basestocks as of late? Just spitballing.

 

[dave1251]

Originally Posted by dailydriver

Originally Posted by wemay

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

Maybe Motul, and Red Line should 'build' an oil with a reduced calcium/sodium, but with even higher POE content than anything they produce currently, with large amounts of 'trimer' moly in them? [dunno]

It likely will not work diester content is capped at less than 10% base oil content.

 

[CT8]

Originally Posted by BLND1

Originally Posted by wemay

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

Could this be why Mobil is pushing group II+ basestocks as of late? Just spitballing.

GPII+ oil is the oil that is in the crankcases most of the + million mile Semi Truck engines.

 

[dblshock]

I have some beautiful 10/30, 15/40 conventional oils to run this summer.

 

[dblshock]

I'd run them all the time, unfortunately at -20F like tonite they become un-workable....couple more months here.

 

[dave1251]

If oil is changed on time and the combustion chamber is cleaned two nessary factors for LSPI are eliminated.

 

[dadto2]

I think I'm going to just keep using the SuperTech Dexos gen2 fill, change it when the OLM tells me too, and add some Regane to the gas tank every 3,000 miles. That's my take-away from this entire thread.

 

[Patman]

Originally Posted by CT8

GPII+ oil is the oil that is in the crankcases most of the + million mile Semi Truck engines.

You can't compare the needs of those semi truck diesel engines to the ones of a typical passenger car engine though. A transport truck engine holds GALLONS of oil, not a few quarts. And those engines spend 99.9% of their lives fully warmed up and are not stressed the same way as a gas engine either.

 

[BLND1]

Originally Posted by CT8

Originally Posted by BLND1

Originally Posted by wemay

Thanks for the critical eye, JAG. They also state, and include a graph in the process, that base stocks have the largest impact on auto ignition as measured using their protocols. As a result, the lower the Grp, the lower the occurance of LSPI. GrpII showing less propensity than III or IV. Until GrpV shows to be the most promising.

Could this be why Mobil is pushing group II+ basestocks as of late? Just spitballing.

GPII+ oil is the oil that is in the crankcases most of the + million mile Semi Truck engines.

I guess I meant in PCMO.

 

[dailydriver]

Originally Posted by Patman

Originally Posted by CT8

GPII+ oil is the oil that is in the crankcases most of the + million mile Semi Truck engines.

You can't compare the needs of those semi truck diesel engines to the ones of a typical passenger car engine though. A transport truck engine holds GALLONS of oil, not a few quarts. And those engines spend 99.9% of their lives fully warmed up and are not stressed the same way as a gas engine either.