- Joined
- Dec 7, 2020
- Posts
- 6,891
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- Location
- Minneapolis, MN
- Ram Year
- 2017 2500 Laramie Crew Cab
- Engine
- 6.4L HEMI
I know this comment will incite a riot, but I'm gonna do it anyway. Full disclosure - I have no cultural or financial interest in ANY lubricant company. As a lifelong engineer, my quest is always to search for the most cost effective designs.
Lubricant film strength tests show Amsoil is significantly stronger than Red Line, for a given viscosity. Since they both are similar price, I am going with Amsoil.
Which has the most dry lubricant addivtive, and how much it helps, is up for discussion. PUP elected to put a whole bunch of soluble moly additive in. Think they were concerned with somebody? (FCA contract, perhaps?) Cam lubrication was the basis for ZDDP (zinc) antiwear additive, which has been cut back from poisoning exhaust catalysts from blowby gases. But too much ZDDP isn't good either, as it gets too active and starts eating too much metal away. Moly is inert (not metallically active) and serves as a coating, as in chassis greases. Is it effective here? I don't think anybody knows. I do know there a a number of lifter / cam failures in forum using the high moly PUP, so I would say no. At least it doesn't prevent all failures.
In terms of viscosity, my estimate is 0W-40 was a hunch specification, not knowledge. My assessment is 5W-30 is the best compromise with highest film strength as well as other attributes (low sheardown, low volatility, low cranking vis, etc. etc.). That said, I'll start with 0W-40 before I consider moving to 5W-30.
FCA / Ram / Chrysler provides zero help or consultation.
Lubricant film strength tests show Amsoil is significantly stronger than Red Line, for a given viscosity. Since they both are similar price, I am going with Amsoil.
Which has the most dry lubricant addivtive, and how much it helps, is up for discussion. PUP elected to put a whole bunch of soluble moly additive in. Think they were concerned with somebody? (FCA contract, perhaps?) Cam lubrication was the basis for ZDDP (zinc) antiwear additive, which has been cut back from poisoning exhaust catalysts from blowby gases. But too much ZDDP isn't good either, as it gets too active and starts eating too much metal away. Moly is inert (not metallically active) and serves as a coating, as in chassis greases. Is it effective here? I don't think anybody knows. I do know there a a number of lifter / cam failures in forum using the high moly PUP, so I would say no. At least it doesn't prevent all failures.
In terms of viscosity, my estimate is 0W-40 was a hunch specification, not knowledge. My assessment is 5W-30 is the best compromise with highest film strength as well as other attributes (low sheardown, low volatility, low cranking vis, etc. etc.). That said, I'll start with 0W-40 before I consider moving to 5W-30.
FCA / Ram / Chrysler provides zero help or consultation.