Best GM Gen V DI engine oil - with or without E85

[LF4]

All,

First time poster. First, I wanted to say thanks for all the informative posts. As a engineer, I've picked up on design tradeoffs that I wasn't aware of, and I'm more aware of the evolution of oil formulations. My perception of the well-known brands like Mobil 1, Valvoline, etc was that they were like Kleenex or Coca-Cola--selling the same old formulation for decades. Thanks for straightening me out.

For DI engines, there's been a lot of discussion lately about preventing LSPI and reducing intake valve deposits. The other talking points are preventing washout from ethanol and shear stability at very high load and temperatures (e.g. PSSI). It's probably not a coincidence that these discussions are happening, considering the proliferation of highly-boosted, low-displacement engines. In the Cadillac user groups, there are some ATS-Vs and CT4-V Blackwings that are on their 3rd or 4th LF4 (3.6L twin turbo) engine due to track use. That's scary.

Questions:

• What's the consensus on LSPI? Does every API SP oil do a good enough job to eliminate the need to buy a specialty oil like Driven Racing DI30/DI40/DI50? Lake Speed made a splash with his discussion about LSPI and got a lot of people (myself included) to buy their DI oil. Now, looking at the available options, I don't think anyone can claim LSPI protection as a unique selling point.
• What about preventing intake valve deposits? My understanding is, if you want to reduce IVDs, pick an oil with a low NOACK (credit to @RDY4WAR) and/or find an oil with a good CCS (credit to @Gokhan). When talking with the staff at Driven, they claim that the DI30/DI40/DI50 oils do a great job of preventing IVDs, and to be honest, I don't know how to judge that claim.
• What makes an oil resistant to ethanol washout? A lot of track-oriented folks recommend changing oil at 50% life based on the viscosity loss they're seeing in oil analysis reports--but that's sidestepping root cause investigation. Driven recommended that I run GP-1 while on E85 and switch back to DI30/DI40/DI50 when I'm not on E85. I've heard various reasons for why certain synthetic blends (as opposed to full synthetic) and additive packages can combat washout, and can't make sense of it.

Of the available options, what do you recommend for daily driven, highly-boosted DI engines running 1) pump gas 2) E30-E85? My short list is as follows, but let me know if there's something I missed:

• AMSOIL Signature Series (93)
• Driven DI30/DI40/DI50 (93)
• Driven GP-1 (E30-E85)
• HPL Premium Plus Passenger Car (93)
• HPL Bad Ass Racing (E30-E85)

Don't be afraid about hurting my feelings. Thanks!

 

[Jetronic]

If you want to prevent washout by ethanol, you need an oil component that's more polar and more viscous than ethanol, so the preferred bonding with the metal in the engine is with the oil.

 

[Kalle.J]

Of the available
options, what do you recommend for daily driven, highly-boosted DI engines running 1) pump gas 2) E30-E85? My short list is as follows, but let me know if there's something I missed:

• AMSOIL Signature Series (93)
• Driven DI30/DI40/DI50 (93)
• Driven GP-1 (E30-E85)
• HPL Premium Plus Passenger Car (93)
• HPL Bad Ass Racing (E30-E85)

Welcome!

You missed Dexos R and Porsche A40 spec.
If you are worried about IVD, running intake cleaner once or twice per year or adding oil catch-can makes sense then obsessing about the perfect oil.

 

[BMWTurboDzl]

All,

First time poster. First, I wanted to say thanks for all the informative posts. As a engineer, I've picked up on design tradeoffs that I wasn't aware of, and I'm more aware of the evolution of oil formulations. My perception of the well-known brands like Mobil 1, Valvoline, etc was that they were like Kleenex or Coca-Cola--selling the same old formulation for decades. Thanks for straightening me out.

For DI engines, there's been a lot of discussion lately about preventing LSPI and reducing intake valve deposits. The other talking points are preventing washout from ethanol and shear stability at very high load and temperatures (e.g. PSSI). It's probably not a coincidence that these discussions are happening, considering the proliferation of highly-boosted, low-displacement engines. In the Cadillac user groups, there are some ATS-Vs and CT4-V Blackwings that are on their 3rd or 4th LF4 (3.6L twin turbo) engine due to track use. That's scary.

Questions:

• What's the consensus on LSPI? Does every API SP oil do a good enough job to eliminate the need to buy a specialty oil like Driven Racing DI30/DI40/DI50? Lake Speed made a splash with his discussion about LSPI and got a lot of people (myself included) to buy their DI oil. Now, looking at the available options, I don't think anyone can claim LSPI protection as a unique selling point.
• What about preventing intake valve deposits? My understanding is, if you want to reduce IVDs, pick an oil with a low NOACK (credit to @RDY4WAR) and/or find an oil with a good CCS (credit to @Gokhan). When talking with the staff at Driven, they claim that the DI30/DI40/DI50 oils do a great job of preventing IVDs, and to be honest, I don't know how to judge that claim.
• What makes an oil resistant to ethanol washout? A lot of track-oriented folks recommend changing oil at 50% life based on the viscosity loss they're seeing in oil analysis reports--but that's sidestepping root cause investigation. Driven recommended that I run GP-1 while on E85 and switch back to DI30/DI40/DI50 when I'm not on E85. I've heard various reasons for why certain synthetic blends (as opposed to full synthetic) and additive packages can combat washout, and can't make sense of it.

Of the available options, what do you recommend for daily driven, highly-boosted DI engines running 1) pump gas 2) E30-E85? My short list is as follows, but let me know if there's something I missed:

• AMSOIL Signature Series (93)
• Driven DI30/DI40/DI50 (93)
• Driven GP-1 (E30-E85)
• HPL Premium Plus Passenger Car (93)
• HPL Bad Ass Racing (E30-E85)

Don't be afraid about hurting my feelings. Thanks!

The LSPI test is performed on a modified Ford 4-cylinder Ecoboost. So an oil either passes or it doesn't but we will never know by how much an oil passed.

Ethanol washout, not sure what they mean by that, can only be addressed by higher viscosity and proper tuning.

 

[slacktide_bitog]

GM's dexos oils are designed to accommodate E85.

Any d1g3 or dexosR should be more than adequate for your Gen V DI with or without E85

In fact, LSPI is the reason GM started dexos in the first place. GM also pushes E85 flex fuel more heavily than anyone else. They also have the OLM to calculate an OCI based on your driving conditions, and now they have a hard limit of 7500 miles programmed into it. That is, modern dexos-era GM cars will never suggest any OCI greater than 7500 miles or one year (the only exception is the Chevy Volt, a PHEV, where the max is 2 years, no mileage limit)

However, M1 0w40 is probably the most popular oil for track use.

 

[twX]

API SP and Dexos 1 Gen 3 have the most stringent LSPI tests currently. When API SQ is released in a few days, it will have the most stringent test for LSPI. Specialty oils are often formulated with LSPI in mind, but they generally aren't API approved and they don't do any engine tests to verify LSPI performance. If you use a non-approved oil, you'll want it to have well under 1500 ppm calcium.

Most of the oil that reaches the intake valves is in the form of mist, not vapour. An oil with lower Noack probably won't help very much. There are no standard engine oil tests for IVD. The industry has addressed the IVD problems through changes to engine design instead of oil formulation. There's some evidence that less VII is better for IVD, but I wouldn't be basing my choice of oil on IVD performance, as there's not much data to go by, and it probably won't make much of a difference anyway.

E85 causes much higher fuel dilution on cold starts. However, ethanol is so volatile that it all boils out of the crankcase once the engine is up to temperature. Even though it eventually boils off, it still degrades the oil and promotes sludge, which might require better oil or shorter OCIs. Dexos 1 Gen 3 requires much better sludge performance than API SP, and E85 might be why GM requires that. For short-tripping in cold weather, I would avoid E85 entirely.

 

[twX]

Cough cough Euro manufacturer specs

Which euro standards do you suppose have more stringent LSPI tests than API SP or SQ? Most of them don't even have LSPI tests. The Mercedes LSPI test is almost certainly less stringent than API SP, and especially SQ. The few ACEA specs that have LSPI tests use the same test as SP, which is less stringent than SQ.

 

[Kalle.J]

Which euro standards do you suppose have more stringent LSPI tests than API SP or SQ? Most of them don't even have LSPI tests. The Mercedes LSPI test is almost certainly less stringent than API SP, and especially SQ. The few ACEA specs that have LSPI tests use the same test as SP, which is less stringent than SQ.

Should you not already know that if you are making this claim?
"API SP and Dexos 1 Gen 3 have the most stringent LSPI tests currently. When API SQ is released in a few days, it will have the most stringent test for LSPI."

As far as I can tell the LSPI test is the same for API SN+, SP and SQ except for the aged oil test.

MB 229.51, MB 229.52, MB 229.71 and BMW 17FE has LSPI in the spec. Don't know about VW and Porsche.
We have had real world LSPI-tests running for a long time