How oil affects LSPI

[PeterPolyol]

Originally Posted By: AZjeff
Did anyone ever not use a PCMO because the NOACK was too low? Is there any downside to 7.6 vs 11.1?
The ideal NOACK volatility would be 0%, so I'll say no

The summary suggests that high concentrations of Mg most negatively affects "LPSI" with low viscosity oils, but most positively with high viscosity oils, am I reading that right?

 

[wemay]

Yes, the study states that viscosity is significant and that lower viscosity with higher Magnesium yielded lower occurrence of LSPI.

 

[Gokhan]

Originally Posted By: irv
If I understand this correctly, you are saying an oil requires both magnesium and calcium to ensure it it neutralizes all acids and not just some?

Good TBN retention means nothing if it is not doing it's job neutralizing acids.

Calcium neutralizes everything. Magnesium doesn't neutralize everything and for that reason it lasts longer (longer TBN retention). You need both for neutralizing everything and TBN retention. You also need to reduce calcium and add magnesium for LSPI protection. Note that type of detergent also greatly affects wear protection and they also need to test the detergent in the finished oil for wear protection.

Originally Posted By: jwa
So maybe Redline, despite it's high calcium, wouldn't dramatically increase LSPI event chances due to also having high ZDDP and moly.

Calcium is the main culprit for LSPI. ZDDP and moly help but chances are that if you have a lot of calcium, they won't help much.

Originally Posted By: SubieRubyRoo
The way I understand that is calcium does not necessarily have to be reduced... but the ratio of calcium to magnesium must be less than pre-T/GDI engines to combat LSPI.

If you add all of the factors together, I see no real reason why you couldn't still have an oil with say 2300ppm of calcium, 1500ppm of magnesium, and a good dose of ZDDP/moly. The higher magnesium and ZDDP/moly will offset the calcium. That's the way I read it, especially when combined with the fact that NOACK and viscosity are not significant factors.

Maybe SOJ will weigh in.

Again, calcium is the main culprit and it seems to act as a catalyst in generating the LSPI reactions. ZDDP, moly, and lower viscosity are secondary in reducing LSPI. Regardless, you can't go bonanza on additive ppm's because of SAPS limits in any street-use motor oil.

Regarding viscosity, I noticed that M1 15W-50 is one of the very few Mobil 1 oils not LSPI-certified (not API SN Plus) -- this is why I looked up this SAE paper. Since it has little calcium and a lot of magnesium, it's either that its high viscosity is causing LSPI or they didn't bother to certify it because it's not a common viscosity grade for newer cars.

 

[Olas]

The most effective practice is to stop oil entering the combustion chamber in the first place.

 

[AZjeff]

Does D1G2 oil mean anything to those of us with GDI but no turbo? Possible less timing chain wear is good for all engines but beyond that..?

 

[irv]

Originally Posted By: Gokhan
Originally Posted By: irv
If I understand this correctly, you are saying an oil requires both magnesium and calcium to ensure it it neutralizes all acids and not just some?

Good TBN retention means nothing if it is not doing it's job neutralizing acids.


Calcium neutralizes everything. Magnesium doesn't neutralize everything and for that reason it lasts longer (longer TBN retention). You need both for neutralizing everything and TBN retention. You also need to reduce calcium and add magnesium for LSPI protection. Note that type of detergent also greatly affects wear protection and they also need to test the detergent in the finished oil for wear protection.


Thanks for the explanation.

Originally Posted By: AZjeff
Does D1G2 oil mean anything to those of us with GDI but no turbo? Possible less timing chain wear is good for all engines but beyond that..?


Curious with this as well? I assume D1G2 will not hurt but is it necessary in your engine if you don't have a Turbo?

 

[Gokhan]

Originally Posted By: AZjeff
Does D1G2 oil mean anything to those of us with GDI but no turbo? Possible less timing chain wear is good for all engines but beyond that..?

dexos1 Gen 2 also has less oxidation (higher-quality base oil, such as more GTL and/or PAO), meaning longer OCIs and cleaner engines.

https://noln.net/2017/06/30/new-generation-dexos-acea-specifications/

 

[bigj_16]

Originally Posted By: SubieRubyRoo
The way I understand that is calcium does not necessarily have to be reduced... but the ratio of calcium to magnesium must be less than pre-T/GDI engines to combat LSPI.

If you add all of the factors together, I see no real reason why you couldn't still have an oil with say 2300ppm of calcium, 1500ppm of magnesium, and a good dose of ZDDP/moly. The higher magnesium and ZDDP/moly will offset the calcium. That's the way I read it, especially when combined with the fact that NOACK and viscosity are not significant factors.

Maybe SOJ will weigh in.

Magnesium "accelerates" the effects of calcium for LSPI. Moly and ZDP can somewhat offset LSPI, but won't counteract a lot of calcium. Looks like the cutoff for calcium is 1500 ppm. Above that, and LSPI really starts to take off.
It is pretty apparent what part calcium plays. All the add packs in D1G2 oil, that I have seen, have dropped calcium significantly.
In a few years, most likely the vast majority of oil will have the same add pack.
The only thing to discuss will be the color of the bottle.

 

[Gokhan]

Originally Posted By: bigj_16
In a few years, most likely the vast majority of oil will have the same add pack.
The only thing to discuss will be the color of the bottle.

There are only a handful additive companies out there and the additive packs are usually sold for a given certification (API, ACEA, dexos, gasoline, diesel, motorcycle, etc.). So, if one company sells six different additive packs and if there are six companies, that makes 36 different additive packs. It's plenty. For a given application, you probably get about a dozen varieties of additive packs.

 

[Kjmack]

I read this full discussion twice and still cant understand why 0W-any weight oil is harmful to timimg chains . Especially in winter conditions . Is not quicker oil flow better for chain tensioners ?

 

[OilUzer]

Originally Posted by Kjmack
I read this full discussion twice and still cant understand why 0W-any weight oil is harmful to timimg chains . Especially in winter conditions . Is not quicker oil flow better for chain tensioners ?


Maybe there is more than cSt and hths that determines a "thicker base" oil! idk
however, a lot of 0Wy or 5Wy or 10Wy that I've checked, have very similar KV100 and hths ...
and the engine doesn't spend much time in the 0W region of the oil ...
Based on the above, i agree with you ... Until experts convince me otherwise!

 

[CT8]

Originally Posted by Kjmack
I read this full discussion twice and still cant understand why 0W-any weight oil is harmful to timimg chains . Especially in winter conditions . Is not quicker oil flow better for chain tensioners ?
Most Euro engines are ohc. 0W.40 is a popular euro grade.