Evidently the 4-ball wear test is ASTM 4172 but it appears a different temp and RMP can be used for example :
Both the ASL 5w-30 and ATM 10w-30 has listed on the Amsoil website the following for both oils .
ASTM 4172 @ 40kgf 75c 1200RPM
The XL 7500 group III " I for get the vi " and the AMO 10w-40 lists this .
ASTM D4172 @ 40kgf 150c 1800 RPM
For a difference in 600 RPM of spinning those 4 balls in whatever way it's done .
I did not check any other oils they offer for these differences but am curious as to why the RPM differs and is not a constant
I'd just like to know for when I run across other tests on the net or elsewhere I'll be more educated on the 4-ball wear testing procedures and why they differ in terms of temps and RPM's used .
Both the ASL 5w-30 and ATM 10w-30 has listed on the Amsoil website the following for both oils .
ASTM 4172 @ 40kgf 75c 1200RPM
The XL 7500 group III " I for get the vi " and the AMO 10w-40 lists this .
ASTM D4172 @ 40kgf 150c 1800 RPM
For a difference in 600 RPM of spinning those 4 balls in whatever way it's done .
I did not check any other oils they offer for these differences but am curious as to why the RPM differs and is not a constant

I'd just like to know for when I run across other tests on the net or elsewhere I'll be more educated on the 4-ball wear testing procedures and why they differ in terms of temps and RPM's used .
