hey peeps - so I've spent several hours scanning the lab results from 540rat and I'd like some confirmation about what the 90,000 psi 'magic number' really means. Is that the 'requirement' for flat-tappet cam engines? I own several 'flat-tappet' hot rods, including my mighty Cummins 5.9 (solid cam), and so I've got a couple questions...
I talked with the tech folks at Shell and they claim their Rotella T4, 5 and 6 all have the 'flat-tappet' package, so I've been running Shell Rotella T4 10W30 in my hot rods, but alas the info from 540rat does not specifically list the 10W30, so I don't know how it rates.
It does list the Shell Rotella 5W30 Gas Truck oil with a nice rating of ~96,000 psi, which I am now leaning towards for my hot rods.
It also lists both the new and old Rotella 15W40 diesel oils, both of which rate in the low 70,000 range - not at/above the 90,000 number...which was very disheartening considering it's what I've been running in my solid cam Cummins.
So, looking at the results there seem to be three local off-the-shelf contenders of 'normal' oil that I'm leaning towards for my hot rods, all of which are above the 90,000 magic number:
- Quaker State Ultimate Durability 5W30, ~133,000 psi rating
- NAPA 5W30, ~105,000 psi rating
- Shell Rotella 5W30 Gas Truck oil, ~96,000 psi rating
All of these are full synthetic, and all of them list "Dexos" on the bottle - wonder what that means...
I also have a fresh 440 that needs to be broken in, and I am VERY curious about the Lucas Break In Oil I bought for the initial break-in - it only rates at ~49,000 psi - not even worth saying how low it rates...and this is a 'break-in' oil?
Meanwhile...I am still trying to determine what to run in my Cummins - none of the local 'off-the-shelf' contenders are rated above 90,000 psi; not Rotella, not Delo, so I may have to resort to the expensive mail order oils like Amsoil...and maybe they are worth it...?
Here is the link to the lab data from 540rat - https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/
Would appreciate any thoughts/recommendations.