1992 7.4 Oil?

[Schurkey]

The "Diesel" oil is a terrible idea, given that many "Diesel" oils are no longer cross-certified for spark-ignition vehicles. They may or may not have "extra zinc" but they also have an additive package set-up for high-soot that isn't appropriate for spark-ignition engines.

"Diesel" oil--back when it was cross-certified for spark ignition, too--was a popular if less-than-optimum choice for those with flat tappet cams. Those days are mostly gone. The "zinc" levels have been reduced, the additives are wrong...not a top choice any more.

The whole panic over "zinc" (actually ZDDP) levels in oil was mostly a manufactured (phony) "crisis" when cam companies started selling crappy, bottom-feeder Chinese lifters and cam cores. Of course the failure rate went sky-high. The cam companies blamed the oil instead of the faulty product they were selling, and the magazines picked-up on that.

 

[Caman96]

Clean oil, correct weight.

 

[95burban]

The "Diesel" oil is a terrible idea, given that many "Diesel" oils are no longer cross-certified for spark-ignition vehicles. They may or may not have "extra zinc" but they also have an additive package set-up for high-soot that isn't appropriate for spark-ignition engines.

"Diesel" oil--back when it was cross-certified for spark ignition, too--was a popular if less-than-optimum choice for those with flat tappet cams. Those days are mostly gone. The "zinc" levels have been reduced, the additives are wrong...not a top choice any more.

The whole panic over "zinc" (actually ZDDP) levels in oil was mostly a manufactured (phony) "crisis" when cam companies started selling crappy, bottom-feeder Chinese lifters and cam cores. Of course the failure rate went sky-high. The cam companies blamed the oil instead of the faulty product they were selling, and the magazines picked-up on that.

Maybe or maybe not. I’ve used it for several years in gas and diesel engines including the alky big block in my flat bottom. I’m going to keep using it with great results.

 

[Schurkey]

Maybe or maybe not. I’ve used it for several years in gas and diesel engines including the alky big block in my flat bottom. I’m going to keep using it with great results.

LOOK at the "Diesel" oil you're buying. Make sure it's cross-rated for spark-ignition engines if you're using it in a spark-ignition engine.

 

[95burban]

Maybe I’m safe, it says for gas engines too. I’ve been using this lately. 23.00 for two gal of oil.

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[GMC_YA_L8R]

Maybe I’m safe, it says for gas engines too. I’ve been using this lately. 23.00 for two gal of oil.

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You're probably safe. I run the same stuff in my TBI 350 and it's a good oil. Made by Warren, around 1300ppm of Zinc, available everywhere and for a great price.

However, if you still have a cat on your truck it *could* cause some issues but that possibility is likely very low.

 

[Scooterwrench]

I like VR1. It has treated me well in everything I pour it into which is everything I own. I run 10w-30 in my small engines and my 355 in the winter,20w-50 in the summer and in my Harley year round.

 

[Pinger]

Maybe I’m safe, it says for gas engines too. I’ve been using this lately. 23.00 for two gal of oil.

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API CK-4 is pretty uncommon. Most are stuck at CF - an obsolete spec from 1992.

 

[DerekTheGreat]

According to 540rat, the bottom line for quality oil is film strength. Without it, you've got metal on metal. Doesn't matter what package it takes the oil to achieve high film strength, but "high zinc" doesn't guarantee high film strength. I used to run diesel oil (5W-40 Rotella T6) in all of my vehicles, then I came across his ranking list for oils. Now I run 5W-30 full synthetic Quaker State. If I can't find that, it'll be Mobil 1. I've attached the file (circa 2019) for anyone who wants to look at it. Chances are, your oil is in there. By the way, most of the diesel oils tested poorly, especially Rotella.

 

[Pinger]

According to 540rat, the bottom line for quality oil is film strength. Without it, you've got metal on metal. Doesn't matter what package it takes the oil to achieve high film strength, but "high zinc" doesn't guarantee high film strength. I used to run diesel oil (5W-40 Rotella T6) in all of my vehicles, then I came across his ranking list for oils. Now I run 5W-30 full synthetic Quaker State. If I can't find that, it'll be Mobil 1. I've attached the file (circa 2019) for anyone who wants to look at it. Chances are, your oil is in there. By the way, most of the diesel oils tested poorly, especially Rotella.

The oil film strength is what is at play during 'hydrodynamic' lubrication. That is, when there is a continuous unbroken film of oil between the components. That film will break down under extreme loads and it is then that the anti-wear additives come to the fore as all that is preventing metal to metal contact.
The greater the film strength though, the less likely the film is to rupture and lean on the anti-wear additives. Conversely, weak film strength oils will be more prone to rupture and thus place more demands on the anti-wear additives - which will deplete sooner in service shortening the oil's useful life.

Film strength is one aspect. Oxidation resistance is as important and along with the chemistry/quality of the base oil is influenced by other factors. Eg, resistance to foaming contributes greatly to oxidation resistance and is provided by inclusion of an anti-foam additive. The complete additive package is important and invariably, when oils are changed it isn't because the oil is bad (unless thickened by oxidation or laden with soot etc) but because the additive package has depleted. Eg, there is only so much soot the detergent additive can hold suspended, etc, etc.