Redline 5-w30 in turbocharged DI engines

[OVERKILL]

Not so sure. Not all DI FI engines experience it IMO it primarily depends on the programming. It's akin to constantly short shifting an engine (i.e. Low RPM but high load) for max fuel efficiency. I suspect it's possible to occur in any FI engine (DI or PI). We just never saw it with FI PI because at the time these engines were in service the emissions and FE requirements weren't as stringent and turbos were larger so boost came on higher in the rev range.

My IMO of course.

I don't think it's possible in a port injected engine due to the issue being predicated on both high compression and when the fuel is introduced. With a port injected engine, the fuel is there during the intake stroke and of course the entire compression stroke, because it is introduced in the intake air charge and tends to atomize a lot better as well. On top of that, the A/F ratio is generally richer and a port injected engine won't tolerate the same compression ratio.

With DI you have the fuel being introduced as a variable after the intake air charge is already being compressed and heated (think: diesel) and LSPI is that spontaneously lighting off by virtue of some hot element in the chamber, which seems to be related to calcium and other oil constituents that make their way into the combustion chamber and providing those "embers". This is made possible by the higher compression and leaner A/F ratios enabled by DI and exasperated by forced induction which of course means an even hotter intake air charge and more dense air mass being compressed during the compression stroke.

Carbureted engines would experience pre-ignition (think run-on) but it typically didn't damage anything. Spark knock/light detonation was far, FAR more common however, and on more advanced FI vehicles, knock sensors were used to keep the A/F and timing right on the ragged edge there to improve efficiency (which I'm sure you already know). The only time spark knock was ever really a big concern was with boosted applications, but this was easily mitigated via enrichment, as evidenced by OEM's whose tunes tended to be on the conservative time for that very reason. But spark knock isn't pre-ignition.

Basically, the parameters that enable LSPI to happen:
- Tight control over A/F beyond what was possible with PI
- Control over WHEN The fuel is injected
- Higher static compression ratios and the ability to couple this with forced induction

Enable these engines to operate in a manner that wasn't possible with port injection IMHO, and that's why this whole LSPI thing blind-sided the industry. You are absolutely right that if you can avoid the "low speed" part, you'll also avoid the pre-ignition, which is likely why marques like BMW didn't seem to suffer from it.

 

[BMWTurboDzl]

I don't think it's possible in a port injected engine due to the issue being predicated on both high compression and when the fuel is introduced. With a port injected engine, the fuel is there during the intake stroke and of course the entire compression stroke, because it is introduced in the intake air charge and tends to atomize a lot better as well. On top of that, the A/F ratio is generally richer and a port injected engine won't tolerate the same compression ratio.

With DI you have the fuel being introduced as a variable after the intake air charge is already being compressed and heated (think: diesel) and LSPI is that spontaneously lighting off by virtue of some hot element in the chamber, which seems to be related to calcium and other oil constituents that make their way into the combustion chamber and providing those "embers". This is made possible by the higher compression and leaner A/F ratios enabled by DI and exasperated by forced induction which of course means an even hotter intake air charge and more dense air mass being compressed during the compression stroke.

Carbureted engines would experience pre-ignition (think run-on) but it typically didn't damage anything. Spark knock/light detonation was far, FAR more common however, and on more advanced FI vehicles, knock sensors were used to keep the A/F and timing right on the ragged edge there to improve efficiency (which I'm sure you already know). The only time spark knock was ever really a big concern was with boosted applications, but this was easily mitigated via enrichment, as evidenced by OEM's whose tunes tended to be on the conservative time for that very reason. But spark knock isn't pre-ignition.

Basically, the parameters that enable LSPI to happen:
- Tight control over A/F beyond what was possible with PI
- Control over WHEN The fuel is injected
- Higher static compression ratios and the ability to couple this with forced induction

Enable these engines to operate in a manner that wasn't possible with port injection IMHO, and that's why this whole LSPI thing blind-sided the industry. You are absolutely right that if you can avoid the "low speed" part, you'll also avoid the pre-ignition, which is likely why marques like BMW didn't seem to suffer from it.

As I understand it with gas engines the injection sequence still starts at the beginning of the intake stroke rather than waiting for as long as possible with diesel. In any case I still think it's the downsized turbochargers which are you say are generating a lot of heat due to the leaner A/F ratio at low rpms and causing auto-ignition of oil droplets. Have an old SAAB 900 lying around where you could add a small turbo?

 

[OVERKILL]

As I understand it with gas engines the injection sequence still starts at the beginning of the intake stroke rather than waiting for as long as possible with diesel. In any case I still think it's the downsized turbochargers which are you say are generating a lot of heat due to the leaner A/F ratio at low rpms and causing auto-ignition of oil droplets. Have an old SAAB 900 lying around where you could add a small turbo?

I don't unfortunately, lol. But yeah, those are parameters (lean A/F beyond what was possible with PI, higher static compression ratio than what was possible with PI, direct control of when the fuel enters the chamber) that I believe combine, in conjunction with a forced air intake charge that ultimately leads to LSPI. It doesn't seem to be an issue on just DI engines (no turbo).

 

[330indy]

"High oxidation show oils with esters. (if you take fresh oils.)
6-12 - oxidation of oil without esters.
35 - with esters about 5%
60-70 - with esters about 10%
But that's with ExxonMobil's Esterex, other esters may show different oxidation."

There is a guy on the Russian Oil Club site that seems very knowledgeable. This data he posted correlates with what I've seen and from Dave at Redline.

M1 oxidation readings are usually under 10.
M1 0w40 - 36
Amsoil - 40-50
Redline - 90-120
Valvoline Restore which they claim is 50% Ester - 115.

These are not exact figures as the type of ester varies, but you can get some sense of ester %.

what is this about?

 

[330indy]

maybe I'll do a half & half cocktail of the pro line (Group 3/4) and the HP (4/5) Redline oil....

Professional-Series 5W30 Motor Oil

Red Line has a reputation with racers and enthusiasts alike for creating products that perform and protect better than any on the market. No compromises.

www.redlineoil.com

 

[addyguy]

I was going to say use it as an additive to fortify regular oil

 

[Vermess]

Calcium is known to causes LSPI in almost a linear way.

ZDDP quenches it exponentially.

IMHO, depends on the ratio of Calcium vs ZDDP.

Is your car tuned???

 

[330indy]

I talked with Dave Granquist at Redline Oil, today
we had an in depth conversation.
He said the low budget oil analyses misread the oxygenated ester molecules, read as oxidation. He stated that they are polarized (esters) and the oxygen atoms make the ester attraction to the engine. Their oils don’t suffer from premature oxidation and the readings are misleading. Also, regarding the correct oil for the new M3 / S58 engine __ it is the low ash Euro series high performance oil. Group 4/5 with the proper additive package. 5w30.
Soon the 0W30 will be added.
so glad I called him today.
all set, having talked with the authority….

Euro-Series 5W30 Motor Oil

Euro-Series 5W30 Motor Oil

www.redlineoil.com

 

[Slow Car Sport Mode]

That's a great oil. Use with confidence.

There are other performance options available which might even be better...

 

[OVERKILL]

I talked with Dave Granquist at Redline Oil, today
we had an in depth conversation.
He said the low budget oil analyses misread the oxygenated ester molecules, read as oxidation. He stated that they are polarized (esters) and the oxygen atoms make the ester attraction to the engine. Their oils don’t suffer from premature oxidation and the readings are misleading. Also, regarding the correct oil for the new M3 / S58 engine __ it is the low ash Euro series high performance oil. Group 4/5 with the proper additive package. 5w30.
Soon the 0W30 will be added.
so glad I called him today.
all set, having talked with the authority….

Euro-Series 5W30 Motor Oil

Euro-Series 5W30 Motor Oil

www.redlineoil.com

Yes, high virgin oxidation is quite normal on oils with any real ester content. We saw it with M1 0W-40 for example and will see it with other lubes as well. Redline is well known on here for having high virgin oxidation, which, as Dave noted, is just an artifact of the esters that is picked up by the UOA process.

 

[330indy]

That's a great oil. Use with confidence.

There are other performance options available which might even be better...

Oh? Like what?

 

[Slow Car Sport Mode]

Oh? Like what?

High Performance Lubricants. And I was impressed with Redline products as well.

Check them out.. https://www.hplubricants.com/

 

[UG_Passat]

I would probably email redline and ask. As late as mid 2021 we have VOA with redline 5w30 was 3k+ calcium which is not great for TGDI/LSPI.

But it has plenty of Molybdenum to make up for it.

 

[SaberOne]

I’ve been running redline 5/20 for about five years in my LS3 with no issues.

 

[4WD]

I don't think it's possible in a port injected engine due to the issue being predicated on both high compression and when the fuel is introduced. With a port injected engine, the fuel is there during the intake stroke and of course the entire compression stroke, because it is introduced in the intake air charge and tends to atomize a lot better as well. On top of that, the A/F ratio is generally richer and a port injected engine won't tolerate the same compression ratio.

With DI you have the fuel being introduced as a variable after the intake air charge is already being compressed and heated (think: diesel) and LSPI is that spontaneously lighting off by virtue of some hot element in the chamber, which seems to be related to calcium and other oil constituents that make their way into the combustion chamber and providing those "embers". This is made possible by the higher compression and leaner A/F ratios enabled by DI and exasperated by forced induction which of course means an even hotter intake air charge and more dense air mass being compressed during the compression stroke.

Carbureted engines would experience pre-ignition (think run-on) but it typically didn't damage anything. Spark knock/light detonation was far, FAR more common however, and on more advanced FI vehicles, knock sensors were used to keep the A/F and timing right on the ragged edge there to improve efficiency (which I'm sure you already know). The only time spark knock was ever really a big concern was with boosted applications, but this was easily mitigated via enrichment, as evidenced by OEM's whose tunes tended to be on the conservative time for that very reason. But spark knock isn't pre-ignition.

Basically, the parameters that enable LSPI to happen:
- Tight control over A/F beyond what was possible with PI
- Control over WHEN The fuel is injected
- Higher static compression ratios and the ability to couple this with forced induction

Enable these engines to operate in a manner that wasn't possible with port injection IMHO, and that's why this whole LSPI thing blind-sided the industry. You are absolutely right that if you can avoid the "low speed" part, you'll also avoid the pre-ignition, which is likely why marques like BMW didn't seem to suffer from it.

My old carb’d Mopar’s had stop, start, won’t start, and won’t stop

 

[PimTac]

My old carb’d Mopar’s had stop, start, won’t start, and won’t stop

I think that was a standard feature back then.

Did the engine stop during left hand turns?

 

[4WD]

I think that was a standard feature back then.

Did the engine stop during left hand turns?

I don’t recall LH turn issues