DrewNJ posted a link to this great article that rated oils in a very controlled, evenly compared method. The author does this type of analysis for the industry. I reduced the number of entries to the ones that are commonly discussed.
This is a very valid rating system / test process. M
Maybe Drew can post the link again, it is a long read in full length but good reading if you are into it.
Lower ranked oils are not necessarily “bad”, they simply don’t provide as much wear protection capability as higher ranked oils. If you have been running a low ranked oil in your engine without issue, that does not mean you have switch to a different oil, and it also does not mean you were using a great oil. It only means that your engine’s wear protection needs have not exceeded that oil’s capability. And as long as your engine’s needs don’t exceed that oil’s capability, you will never have a problem. But, if unexpected circumstances come up that make your engine’s needs exceed that oil’s capability, such as an overheating condition, an oiling condition, a loading condition, some parts heading south, or whatever, your engine can end up junk. But, if you’d been using an oil with a much higher capability, it could still provide enough extra protection to save your engine. So, each person has to decide for themselves, which motor oil provides the wear protection capability they are comfortable with, for any given engine build.
For the test results in the Wear Protection Ranking List, the HIGHER the psi value, the BETTER the wear protection. And this applies to ALL engines, including ANY High Performance flat tappet engine. An easy way to use this ranking list, is to find an oil you are familiar with, then look at the oils ranked higher, which provide better wear protection, and look at oils ranked lower, which provide less wear protection.
You cannot advance your knowledge into the future by clinging to the incorrect thinking of the past. This is the 21st Century, and we no longer have to guess or use trial and error to decide on which oil to use. Now, we have documented wear test data available. So the future is here, and all we have to do is look at the Ranking List, to choose an oil that provides a wear protection capability level we are comfortable with for any given build.
The “Wear Protection” test data here DIRECTLY APPLIES to flat tappet lobe/lifter interfaces (no matter how wicked the engine), pushrod tip/rocker arm interfaces, non-roller tip rocker arm/valve stem tip interfaces, distributor gear/cam gear interfaces, mechanical fuel pump pushrod tip/cam eccentric interfaces, and all highly loaded engine interfaces.
Traditional 15W40 and 5W40 Diesel oils formulated for big trucks and heavy equipment, rank overall between number 33 and 165. But, if you omit the highest ranked traditional Diesel oil which is FAR, FAR MORE CAPABLE than all the other traditional Diesel oils, the rest only rank between 96 and 165. The poor wear protection performance of all but the one particular top ranked Diesel oil, makes it very clear that in general, Diesel oils are a poor choice for High Performance gas engines.
So, as you can see, oil viscosity plays no particular role in an oil’s wear protection capability. As mentioned above, an oil’s wear protection capability is determined by its base oil and its additive package “as a whole”, with the primary emphasis on the additive package, which contains the extreme pressure anti-wear components, which has nothing to do with viscosity.
I generally recommend that people choose a highly ranked motor oil to begin with, since highly ranked oils don’t need any additional help. And to use that oil just as it comes, right out of the bottle, with NO aftermarket additives at all. However, there is also data included below from testing a several different aftermarket motor oil additives, for informational purposes only, just to show how these additives actually work compared to their claims. But, I do NOT endorse them nor recommend their use.
FOR THE RECORD, I am NOT connected in any way to the Motor Oil or Aftermarket Additive Industry. I have absolutely no interest in what products people choose to use. So, I DO NOT promote any particular brand. I only share the results that come out of my Engineering tests, good or bad.The Wear Protection reference categories are:
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• Over 105,000 psi = INCREDIBLE wear protection
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• 90,000 to 105,000 psi = OUTSTANDING wear protection
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• 75,000 to 90,000 psi = GOOD wear protection
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• 60,000 to 75,000 psi = MODEST wear protection
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• Below 60,000 psi = UNDESIRABLE wear protection
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The HIGHER the psi value, the BETTER the Wear Protection.
#67. 10W40 Mobil 1 Racing 4T, four stroke Motorcycle oil, synthetic = 93,661 psi
This oil claims to meet or exceed API SN.zinc = TBD
phos = TBD
moly = TBD
#130. 5W40 MOBIL 1 TURBO DIESEL TRUCK synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4 and ACEA E7 = 74,312 psi
zinc = 1211 ppm
phos = 1168 ppm
moly = 2 ppm
#161. 5W40 SHELL ROTELLA T6 Diesel Oil, synthetic, API CJ-4, CI-4 Plus, CI-4, CH-4, SM, SL = 67,804 psi
zinc = TBD
phos = TBD
moly = TBD
#169. 10W40 Valvoline 4 Stroke Motorcycle Oil, API SJ, conventional = 65,553 psi
zinc = 1154 ppm
phos = 1075 ppm
moly = 0 ppm
#182. 10W40 Spectro Motor-Guard High Performance Motorcycle Oil, API SL, conventional = 57,977 psi
zinc = 1800 ppm (claimed on bottle)
phos = 1800 ppm (claimed on bottle)
moly = TBD
