Nice discussion. Started with EP grease went on to ingredients of grease, its consistency and ended with EP.
I support John's arguments and ofcourse he gave the facts only. I would like to add some more points here.
"Grease making is an art & not science: This is an age old argument. Some agree some disagree".
SOME INFLUENCE:
Oil viscosity has some influence. right. If you go further i mean type of oil. Paraffinic, Naphthaneic & aromatic. They have marakable influence. Its all about solvency effect. FOr eg: for a particular grade of grease (same thickener), aromatic type requires less soap quantity than paraffinic type oil.
One cannot explain the consistency of grease just with base oil viscosity and with one type of soap. Consistency of a grease (for eg NLGI-2) depends on many factors. Type of soap, type of oil, process parameters, even additives (nature/dose) etc.... Well.. i would like to briefly touch on this. Lets make two type of greases (Al complex & BaComplex): take known qty of oil (same type & same viscosity) and take same quantity of both Aluminium complex soap and Barium complex soap. Now you will end up in different NLGI-grades. THis tells you base oil viscosity and soap quantity alone can not explain/determine the consistency of grease.
Normally for low speed high load- base oil with higher viscosity and for high speed low load -oil with lower viscosity work better. when you talk of high temperature, apart from oil viscosity (ofcourse high VI) type of soap plays significant role.
John, by the way what is that NLGI-0000 (i never heard about it) You have introduced this grade?. (hahaha... just kidding)
Cheers
Shiva