Topic: Interesting Gear Oil Test From 2007 For Amsoil

[blackdiamond]

http://www.lastgreatroadtrip.com/wp-content/uploads/2010/11/gear-oil-comparison.pdf

I ran across this test report tonight and found it to be an interesting read. I don't think I have read a more comprehensive report that provided such great descriptions of the tests being performed.  I appreciated the overall tone of the report.  Tests are indicators of how an oil will perform and not absolute proof. 

The test is somewhat outdated but I would guess that the highest rated oils could at least be considered a strong indicator of current formulations.  They didn't test the Valvoline Blend that I am currently running but it should be somewhere between the synthetic and conventional products tested which would make it a solid value that I would expect to perform just fine in my application.

I think we need to understand "off road" to be a broad term not intended to refer to rock crawling. I think Goodyear sells "off road" tires and we don't buy those!

In any case, I wish they had done the final test in the appendix on all of the gear oils and not just the Amsoil. They should have at least run one of the lowest rated oils for comparison, but it's possible that all certified oils would yield indistinguishable results.  The key statement may be the following: "Under standard operating test conditions, the L-37 is considered a severe test that accurately discriminates between gear lubes capable of protecting gears and those that cannot."  I would expect all of the oils tested to pass this test if done at the normal level. I will be trying to learn a bit more about the test as it looks like a phenomenonal test.

[SqWADoosh]

I think we need to understand "off road" to be a broad term not intended to refer to rock crawling. I think Goodyear sells "off road" tires and we don't buy those!

MTRs? 

[blackdiamond [OP]]

MTRs? 

http://www.goodyearotr.com/cfmx/web/otr/

MTRs are sold as a truck/SUV tire. The global site sells off road ties for heavy equipment.

[blackdiamond [OP]]

After reading through an old post on the BITOG forum related to this report I was a little bit curious about a few things.  At lunch today I pulled up the SAE J2360 specification for a little "light" reading.  I believe that this is the current specification required for GL-5 certification, but I could be wrong on that.  The test that interested me the most was the Copper Corrosion ASTM D-130 that showed a huge discrepancy between the Amsoil and the Lucas gear oils.  Someone on the BITOG forum indicated that this test wasn't really applicable to gear oils as the additives were known to be corrosive for the "yellow metals" and that differentials don't really contain parts using those metals.  I can't speak to what metals are in a differential, but it made me wonder if the Lucas gear oil is high in whatever additives are in play and the Amsoil has less of them (possibly uses different additives to do the same thing) then it's possible that the Lucas gear oil could be great in a differential application and not a good choice in a transmission.  It's interesting that all of the oils tested were GL-5 certified which makes one wonder about why the Lucas and Royal Purple were so far outside the specification on a couple of the tests, both really lost a lot of their viscosity in the shear test.  The result seems outside the box for what would be expected for a certified oil.  I don't really know what to think about the results...