dexos2 includes an LSPI test???

Status
Not open for further replies.
Joined
Jun 25, 2015
Messages
5,731
Location
New England
Largely a repost of something from another thread, but I thought it was significant enough to be worthy of its own thread. Putting it in the gasoline forum as LSPI is a gas engine issue.

One thing that I just stumbled across online that made my jaw drop is a claim that the dexos2 spec includes an LSPI mitigation test like dexos1 Gen 2, despite the fact that LSPI is not a factor in diesel engines.

'At the UNITI Mineral Oil Technology Congress held in Stuttgart, Germany in April, Thomas Hickl, an engineer for Opel, outlined the evolution of General Motors’ dexos engine oil specification. He noted that lubricants for GM’s new dexos2 specification, which covers diesel engines, will have to pass a low speed stochastic pre-ignition (LSPI) test.

This will be true even though diesel engines don’t experience unpredictable pre-ignition, the hallmark of LSPI, while gasoline engines do. Why, then, does dexos2 even include an LSPI test?

“There can be non-technical reasons to require even things that are not necessary for a diesel engine, which is LSPI protection,” Hickl said.

The non-technical reason has to do with GM opting for a single specification in Europe, which will apply to both gasoline and diesel engine oils. This is because of the high percentage of light-duty diesel engines in Europe, unlike in the U.S., and GM’s move to simplify the supply chain. Elsewhere in the world, GM requires dexos1 for gasoline engines and dexos2 for diesel engines.'

https://fuelsandlubes.com/fli-article/the-new-gm-dexos2-its-complicated/

I had NO idea. All this time I've been pointing posters on here to dexos1 Gen 2 as the only active standard that tests for LSPI and I have been full of it.
DIT drivers looking for higher HTHS oils can apparently use dexos2 as a guide.
 
Originally Posted By: Virtus_Probi
Largely a repost of something from another thread, but I thought it was significant enough to be worthy of its own thread. Putting it in the gasoline forum as LSPI is a gas engine issue.

One thing that I just stumbled across online that made my jaw drop is a claim that the dexos2 spec includes an LSPI mitigation test like dexos1 Gen 2, despite the fact that LSPI is not a factor in diesel engines.

'At the UNITI Mineral Oil Technology Congress held in Stuttgart, Germany in April, Thomas Hickl, an engineer for Opel, outlined the evolution of General Motors’ dexos engine oil specification. He noted that lubricants for GM’s new dexos2 specification, which covers diesel engines, will have to pass a low speed stochastic pre-ignition (LSPI) test.

This will be true even though diesel engines don’t experience unpredictable pre-ignition, the hallmark of LSPI, while gasoline engines do. Why, then, does dexos2 even include an LSPI test?

“There can be non-technical reasons to require even things that are not necessary for a diesel engine, which is LSPI protection,” Hickl said.

The non-technical reason has to do with GM opting for a single specification in Europe, which will apply to both gasoline and diesel engine oils. This is because of the high percentage of light-duty diesel engines in Europe, unlike in the U.S., and GM’s move to simplify the supply chain. Elsewhere in the world, GM requires dexos1 for gasoline engines and dexos2 for diesel engines.'

https://fuelsandlubes.com/fli-article/the-new-gm-dexos2-its-complicated/

I had NO idea. All this time I've been pointing posters on here to dexos1 Gen 2 as the only active standard that tests for LSPI and I have been full of it.
DIT drivers looking for higher HTHS oils can apparently use dexos2 as a guide.


Excellent post! Thanks
 
Originally Posted By: Virtus_Probi

I had NO idea. All this time I've been full of it.


The first step to recovery is admitting you have a problem
smile.gif


Who knows with GM's standards these days. There are the things they tell you and the things they are really doing in the background, and probably little overlap in the story between the two. Nice find!
 
Are European (gas/petrol engine cars) cars driven in a way that LSPI is an issue? I thought they were driven harder and faster, and they don't use low-octane fuel and low-visc oil there. That is, supposedly, 91 RON/87 US octane isn't even available in Europe, except in Russia. And no 0w20 or 0w16, either.

Also, next year, the (gasoline) US-market Corvette is switching to dexos2
 
Originally Posted By: slacktide_bitog
Are European (gas/petrol engine cars) cars driven in a way that LSPI is an issue? I thought they were driven harder and faster, and they don't use low-octane fuel and low-visc oil there. That is, supposedly, 91 RON/87 US octane isn't even available in Europe, except in Russia. And no 0w20 or 0w16, either.

Also, next year, the (gasoline) US-market Corvette is switching to dexos2

Yes, European gas has much higher octane than the US gas. Typically 95 octane is the only gas they have and there is no low/high-octane choice -- as opposed to 87/89/91 in California. My experience has been that higher octane reduces LSPI but doesn't eliminate it.

Also, yes, low-speed preignition (LSPI) only happens at low RPM and high torque. It doesn't apply to high-speed driving, where RPM is high.

My 1985 Corolla has LSPI and so did my 2009 Corolla. It's inevitable if you want to improve fuel economy and throttle response. Sure, I could retard the timing to eliminate it but then the performance and fuel economy sucks. I don't know why it has been a big deal lately.

I don't think the current-generation oils are tested for LSPI. It's something we will see with GF-6 oils and future dexos oils that also carry the GF-6 specification. I don't think oil viscosity affects LSPI much and the oil industry still doesn't seem to know how to reduce LSPI by choice of additives.
 
Originally Posted By: Gokhan

Yes, European gas has much higher octane than the US gas. Typically 95 octane is the only gas they have and there is no low/high-octane choice -- as opposed to 87/89/91 in California. My experience has been that higher octane reduces LSPI but doesn't eliminate it.


Again, Europe uses RON, not (R+M)/2, so their numbers are higher, but their actual ratings are comparable.

Originally Posted By: Gokhan
I don't think the current-generation oils are tested for LSPI. It's something we will see with GF-6 oils and future dexos oils that also carry the GF-6 specification. I don't think oil viscosity affects LSPI much and the oil industry still doesn't seem to know how to reduce LSPI by choice of additives.


re the title and content of the thread, Dexos does check for LSPI.
 
Originally Posted By: Gokhan
... My 1985 Corolla has LSPI and so did my 2009 Corolla. It's inevitable if you want to improve fuel economy and throttle response. Sure, I could retard the timing to eliminate it but then the performance and fuel economy sucks. I don't know why it has been a big deal lately. ...
Are you certain? That description seems more consistent with plain old-fashion knock (aka, pinging) than LSPI.

A GM exec was quoted in the '70s saying "knocking is the sound of fuel economy."
 
Originally Posted By: CR94
Originally Posted By: Gokhan
... My 1985 Corolla has LSPI and so did my 2009 Corolla. It's inevitable if you want to improve fuel economy and throttle response. Sure, I could retard the timing to eliminate it but then the performance and fuel economy sucks. I don't know why it has been a big deal lately. ...
Are you certain? That description seems more consistent with plain old-fashion knock (aka, pinging) than LSPI.

A GM exec was quoted in the '70s saying "knocking is the sound of fuel economy."


LOL, yes where we used to live there was a give way sign on a hill...lots and lots of small engined manual cars would give a decent knock or two as they pulled away from a stop...that's NOT LSPI
 
Originally Posted By: Shannow
Originally Posted By: CR94
Originally Posted By: Gokhan
... My 1985 Corolla has LSPI and so did my 2009 Corolla. It's inevitable if you want to improve fuel economy and throttle response. Sure, I could retard the timing to eliminate it but then the performance and fuel economy sucks. I don't know why it has been a big deal lately. ...
Are you certain? That description seems more consistent with plain old-fashion knock (aka, pinging) than LSPI.

A GM exec was quoted in the '70s saying "knocking is the sound of fuel economy."

LOL, yes where we used to live there was a give way sign on a hill...lots and lots of small engined manual cars would give a decent knock or two as they pulled away from a stop...that's NOT LSPI

It happens only at low RPM and high torque, such as after switching to the high gear. Same happened with my newer Corolla. Is there such a thing as old-fashion preignition and modern preignition? Preignition has been known for decades.
 
Originally Posted By: Gokhan

It happens only at low RPM and high torque, such as after switching to the high gear. Same happened with my newer Corolla. Is there such a thing as old-fashion preignition and modern preignition? Preignition has been known for decades.


LSPI is a phenomenon that occurs in small, highly boosted DIRECT INJECTION gasoline engines.

Good old preignition (that dates back centuries now) is an entirely different mechanism.

Are your toyotas GDI perchance ?
 
Originally Posted By: Shannow
Again, Europe uses RON, not (R+M)/2, so their numbers are higher, but their actual ratings are comparable.

Yes, I know about the two methods and was wondering about that. So, 95 over there is more like 91 (high-octane) in US then. Also, in US, they have up to 93 octane or more in rural areas. They also seem to lower the octane below 87 in high altitudes. In Europe falsely exaggerated octane claims are also a problem.

Originally Posted By: Shannow
re the title and content of the thread, Dexos does check for LSPI.

Yes, but only the latest dexos (2016, 2017?). I was saying that the current oils are probably built to previous dexos specs and they won't make the transition until the GF-6 spec, when they reformulate their blends.
 
Originally Posted By: Gokhan
Yes, but only the latest dexos (2016, 2017?). I was saying that the current oils are probably built to previous dexos specs and they won't make the transition until the GF-6 spec, when they reformulate their blends.


https://www.centerforqa.com/dexos-brand2015/

According to GM, these are the 564 oils that are currently being sold with Dexos 1 Gen 2.
 
Originally Posted By: Shannow
Originally Posted By: Gokhan

It happens only at low RPM and high torque, such as after switching to the high gear. Same happened with my newer Corolla. Is there such a thing as old-fashion preignition and modern preignition? Preignition has been known for decades.

LSPI is a phenomenon that occurs in small, highly boosted DIRECT INJECTION gasoline engines.

Good old preignition (that dates back centuries now) is an entirely different mechanism.

Are your toyotas GDI perchance ?

OK, yes, I see that low-speed preignition in TGDI engines is a lot more severe and harder to prevent. That doesn't mean that it doesn't exist in other engines to a much lesser extent (and, yes it does). That answers my question about why LSPI is a big issue now.
 
Originally Posted By: Shannow
Originally Posted By: Gokhan
Yes, but only the latest dexos (2016, 2017?). I was saying that the current oils are probably built to previous dexos specs and they won't make the transition until the GF-6 spec, when they reformulate their blends.

https://www.centerforqa.com/dexos-brand2015/

According to GM, these are the 564 oils that are currently being sold with Dexos 1 Gen 2.

Ha! Now, that's useful information, thanks!

Apparently calcium is a major culprit in LSPI. Also, moly seems to reduce it. Since Mobil 1 (excluding M1 FS [full-SAPS] 0W-40 A3/B4) uses a lot of magnesium and moly, it seems to be a good choice for TGDI engines.

Oronite LSPI
 
'At a minimum, LSPI can generate an audible knocking noise noticeable to the driver.'

I have yet to hear anything unusual from the 1.5T on Castrol.
 
Originally Posted By: dblshock
'At a minimum, LSPI can generate an audible knocking noise noticeable to the driver.'

I have yet to hear anything unusual from the 1.5T on Castrol.

German Castrol has some magnesium but not as much as Mobil 1 (excluding the all-calcium M1 FS 0W-40) and has no moly. So, perhaps, M1 or M1 EP 5W-30 etc. is a betetr choice for LSPI prevention -- not that you're hearing anything. It's also tested for LSPI through dexos1 Gen 2.
 
Originally Posted By: Gokhan
Originally Posted By: slacktide_bitog
Are European (gas/petrol engine cars) cars driven in a way that LSPI is an issue? I thought they were driven harder and faster, and they don't use low-octane fuel and low-visc oil there. That is, supposedly, 91 RON/87 US octane isn't even available in Europe, except in Russia. And no 0w20 or 0w16, either.

Also, next year, the (gasoline) US-market Corvette is switching to dexos2

Yes, European gas has much higher octane than the US gas. Typically 95 octane is the only gas they have and there is no low/high-octane choice -- as opposed to 87/89/91 in California. My experience has been that higher octane reduces LSPI but doesn't eliminate it.

Also, yes, low-speed preignition (LSPI) only happens at low RPM and high torque. It doesn't apply to high-speed driving, where RPM is high.

My 1985 Corolla has LSPI and so did my 2009 Corolla. It's inevitable if you want to improve fuel economy and throttle response. Sure, I could retard the timing to eliminate it but then the performance and fuel economy sucks. I don't know why it has been a big deal lately.

I don't think the current-generation oils are tested for LSPI. It's something we will see with GF-6 oils and future dexos oils that also carry the GF-6 specification. I don't think oil viscosity affects LSPI much and the oil industry still doesn't seem to know how to reduce LSPI by choice of additives.


European vs US octane sales

type -- US -- European RON
regular 87 -- 91 (this is not available in Europe)
premium 91 -- 95 usually the lowest grade available in Europe
premium 93 -- 98

I don't think either of your Corollas experienced LSPI since it only occurs in TGDI engines. Modern LSPI is not the same as 70s knock/pinging/preignition
smile.gif


In regards to falsely exaggerated octane ratings in Europe, the stations are probably audited at random, unannounced. So if anyone did falsely state octane ratings, they'd be shut down. They do that in the US, so they most likely do it in Europe with their stronger consumer protection laws.
 
Originally Posted By: Gokhan
Originally Posted By: dblshock
'At a minimum, LSPI can generate an audible knocking noise noticeable to the driver.'

I have yet to hear anything unusual from the 1.5T on Castrol.

German Castrol has some magnesium but not as much as Mobil 1 (excluding the all-calcium M1 FS 0W-40) and has no moly. So, perhaps, M1 or M1 EP 5W-30 etc. is a betetr choice for LSPI prevention -- not that you're hearing anything. It's also tested for LSPI through dexos1 Gen 2.


M1 0/40 FS is high in Ca so I use the Castrol Edge 0/40 on the 1.5t Honda.
 
Status
Not open for further replies.
Back
Top