In a sense I think you did answer the question in your first paragraph. I'm not really even considering synthetics at this point. I'm mainly picking on the petroleum oils. I'm forming the opinon, that when it comes to hydraulic oils, all the letters and numbers used by the sellers are just mumbo jumbo to confuse the consumer.
Ernie
"You can plainly see that the Alamo was never built by a military people for a fortress."
Green Jameson, Jan 1836 (in a letter to Sam Houston)
Ernie
"You can plainly see that the Alamo was never built by a military people for a fortress."
Green Jameson, Jan 1836 (in a letter to Sam Houston)