Lake Speed Jr. ... Diesel vs Gas oils

[kschachn]

Last I checked the ESP 5w30 was SP. The ESP 0w30 isn’t because phosphorus is over the 800 ppm limit. I’m sure someone will correct me if it’s changed.

Which is a feature, not a bug (in my book).

 

[Hohn]

Delvac 10w30 and 15w40 are both SP licensed.

That should suffice to establish OK for gasoline engine usage in the majority of instances.

If HDEOs cause elevated wear in gasoline engines, they would also elevate wear in Diesel engines,

Complete fallacy. You are assuming they have identical sources of wear and aggravating/mitigating factors. Agglomerated soot is not a factor in gasoline engines the way it is in diesels. The very additives in diesel oils that target soot management are make those oils less capable where soot loading is not a factor.

Note: less capable just means less capable, not harmful or “bad”.

 

[userfriendly]

That should suffice to establish OK for gasoline engine usage in the majority of instances.

Complete fallacy. You are assuming they have identical sources of wear and aggravating/mitigating factors. Agglomerated soot is not a factor in gasoline engines the way it is in diesels. The very additives in diesel oils that target soot management are make those oils less capable where soot loading is not a factor.

Note: less capable just means less capable, not harmful or “bad”.

A logical fallacy is a flawed argument that may sound convincing but is not supported by evidence.

 

[mobilnissan1991]

My question is, if I use ST 15W40( which is Ck4/SN rated) in my gas F150, should it cause any issues/excess wear?

 

[RDY4WAR]

My question is, if I use ST 15W40( which is Ck4/SN rated) in my gas F150, should it cause any issues/excess wear?

Since it's a 40 grade, the SN rating doesn't mean much. (API ratings don't mean much anyway)

Will it work? Most likely, yes.

Is it ideal? No.

 

[Plumb Bob]

My question is, if I use ST 15W40( which is Ck4/SN rated) in my gas F150, should it cause any issues/excess wear?

No excess wear. You'd be better off with a 40-grade A3/B4, but the HDEO will be fine -- for a long time.

 

[MParr]

Mobil 1 ESP X2 is Dexos D rated and meets VW 508 00 which is required in daughter's new 1.5T gas Jetta. So follow VW requirements or listen to LSJR?

I think I would rather follow VW requirements.

 

[altaylar]

Thousand of UOA of gas engines with HDEO in them right here on this site. Was a hot topic 20 years ago. And a pre-curser to VRP. If you had a filthy engine, a diesel oil would clean it up nice and slow. Extra wear metals would have been shown as an alarming trend for these applications if they were a problem. Maybe on a small scale, say an increase of a few ppm. But that is not going to have a huge effect over the life of the engine.

But the LSPI issue is something interesting. I doubt the HDEO oils are tailored to this issue, so if they cause it, I can see why the correct oil is vastly better. Any pre-ignition is damaging, but seems to be much worse on a turbo GDI engine. Something a diesel just physically would not encounter.

Hence - I see no reason a HDEO in an old small block wouldn't do great, but in a 2.0 VW turbo would be a problem.

Agreed 100%.

Also, the deposits tend to capture wear items that get mobilized and suspended with an oil/additive that cleans them. So I would think maybe the first a few oil changes should not be for UOA to assess the wear protection.

 

[OVERKILL]

Agreed 100%.

Also, the deposits tend to capture wear items that get mobilized and suspended with an oil/additive that cleans them. So I would think maybe the first a few oil changes should not be for UOA to assess the wear protection.

HDEO's aren't formulated as "cleaners" any more than PCMO's are (with the exception of Valvoline Premium Blue Restore, which was an HDEO specifically formulated to clean with a heavy dose of esters). Detergents/Dispersants don't operate like most think they do, they don't break-down and remove existing hard deposits, their role is almost exclusively preventative: Prevent the agglomeration of particulate (dispersants) and prevent them from plating out; keep them in suspension and help them get to the filter (detergents) so they can be removed from circulation.

When this capability is overwhelmed, through intervals that are too long or an application that is more demanding than the lube chemistry is able to handle, you get varnish/lacquer.

Sludge is about the only thing your bog standard modern Group II+/Group III HDEO or PCMO is going to be able to remove, because it's an agglomeration of moisture and particulate with no real bonding mechanism, so it isn't adhered to a surface like varnish/lacquer.

This is why Valvoline's VRP product is such a big deal now, because it actually cleans, and is at an attainable price point for the "price sensitive" consumer.

"Back in the day" it's possible that extremely cheap HDEO's, formulated with Group I, which is a polar base with decent solvency (which is offset by its propensity to break-down and create deposits, rapidly oxidize and other undesirable characteristics) would have done some cleaning, due to their base oil blend, but anything modern with modern approvals is going to be formulated with something like Mobil's Group II+ EHC bases, which are hydrocracked just like Group III is, and thus very dry with poor solvency and no polarity.