I found this response on another forum, but I found it interesting.
Here from the "Horse's Mouth":
Hi Jim,
The Delo 400 LE 15w-40 will be eventually be phased out with the new government emission requirements of the API CK-4. With the current specifications and direction that they are going in, it will be very unlikely that we will see LE again. As you mentioned, you are seeing the LE's replacement, Delo 400 SDE 15w-40(CK-4), starting to stock the shelves. Delo 400 SDE 15W40 uses an ashless additive package to replace the lower zinc & phosphorus levels which were required for Chevron to meet emission requirements of API CK-4 category. We have found the ashless antiwear package improves oxidation control, wear protection, and piston deposit control in both older & newer engines. Unfortunately, we do currently do not have a product that will have similar ZDDP. LE is still being produced sold, but only in larger quantities (not in quart bottles, jugs, or case quantities) and for a limited time. Please see below for a recent statement from our Technology Team regarding SDE and flat tappet cams.
"Wear protection requirements for heavy-duty motor oils are based on industry standard engine dynamometer based tests. In particular, there are three tests that specifically evaluate the oil’s ability to provide valvetrain wear protection. Notably, there are two tests (Cummins ISM and the GM Roller Follower Wear Test) that evaluate wear protection in roller follower valvetrains, and another (Cummins ISB) that evaluates wear protection in FLAT TAPPET valvetrains. This is in addition to other wear tests like the Mack T-12 that evaluates the oils ability to protect against ring/liner wear and bearing corrosion. Engine oils like Chevron’s Delo 400 SDE SAE 15W-40 that also meet the requirements of the API SN category, have also undergone testing specific to confirm protection in gasoline engines as well.
These engine tests are carefully developed to exploit specific performance areas required of lubricants, and often run at operating conditions that far exceed those that are encountered in typical engine operation. By design, the API “C-categories” are developed to be “backward compatible”. This means that when new categories are developed, they adopt the requirements of older categories and add to them. That doesn’t always mean, however, that ALL NEW OILS can be used in ALL OLDER ENGINES. OEMs ultimately make the call regarding what performance spec and viscosity grade is appropriate for a given application. It isn’t clear to me in the situations where we are being challenged, what the real vintage of these products are, and accordingly what the lubricant requirements were/are.
What I can say is that when we choose to rebalance an additive package to address new requirements, it doesn’t involve compromising performance. As it relates specifically to ZDDP, we don’t just simply drop the level of wear protection. Instead, the additive package is rebalanced with other non-Zinc containing wear control additives, and other functional components that allow us to meet or exceed the performance requirements using the fully formulated finished oil.
Oil formulation is a balancing act, and we know that in many cases “less is more”. As such, supplemental additives that purport to enhance wear protection may in fact have the opposite effect. It can also introduce other unpredictable issues regarding seal compatibility, or general interference with the other components that are native to the formulation."
I hope this helps. Let me know if you have any additional questions.
Thank you,
Meggan Frey
Lubetek
Here from the "Horse's Mouth":
Hi Jim,
The Delo 400 LE 15w-40 will be eventually be phased out with the new government emission requirements of the API CK-4. With the current specifications and direction that they are going in, it will be very unlikely that we will see LE again. As you mentioned, you are seeing the LE's replacement, Delo 400 SDE 15w-40(CK-4), starting to stock the shelves. Delo 400 SDE 15W40 uses an ashless additive package to replace the lower zinc & phosphorus levels which were required for Chevron to meet emission requirements of API CK-4 category. We have found the ashless antiwear package improves oxidation control, wear protection, and piston deposit control in both older & newer engines. Unfortunately, we do currently do not have a product that will have similar ZDDP. LE is still being produced sold, but only in larger quantities (not in quart bottles, jugs, or case quantities) and for a limited time. Please see below for a recent statement from our Technology Team regarding SDE and flat tappet cams.
"Wear protection requirements for heavy-duty motor oils are based on industry standard engine dynamometer based tests. In particular, there are three tests that specifically evaluate the oil’s ability to provide valvetrain wear protection. Notably, there are two tests (Cummins ISM and the GM Roller Follower Wear Test) that evaluate wear protection in roller follower valvetrains, and another (Cummins ISB) that evaluates wear protection in FLAT TAPPET valvetrains. This is in addition to other wear tests like the Mack T-12 that evaluates the oils ability to protect against ring/liner wear and bearing corrosion. Engine oils like Chevron’s Delo 400 SDE SAE 15W-40 that also meet the requirements of the API SN category, have also undergone testing specific to confirm protection in gasoline engines as well.
These engine tests are carefully developed to exploit specific performance areas required of lubricants, and often run at operating conditions that far exceed those that are encountered in typical engine operation. By design, the API “C-categories” are developed to be “backward compatible”. This means that when new categories are developed, they adopt the requirements of older categories and add to them. That doesn’t always mean, however, that ALL NEW OILS can be used in ALL OLDER ENGINES. OEMs ultimately make the call regarding what performance spec and viscosity grade is appropriate for a given application. It isn’t clear to me in the situations where we are being challenged, what the real vintage of these products are, and accordingly what the lubricant requirements were/are.
What I can say is that when we choose to rebalance an additive package to address new requirements, it doesn’t involve compromising performance. As it relates specifically to ZDDP, we don’t just simply drop the level of wear protection. Instead, the additive package is rebalanced with other non-Zinc containing wear control additives, and other functional components that allow us to meet or exceed the performance requirements using the fully formulated finished oil.
Oil formulation is a balancing act, and we know that in many cases “less is more”. As such, supplemental additives that purport to enhance wear protection may in fact have the opposite effect. It can also introduce other unpredictable issues regarding seal compatibility, or general interference with the other components that are native to the formulation."
I hope this helps. Let me know if you have any additional questions.
Thank you,
Meggan Frey
Lubetek