I just saw this link on another forum. Thought it was very good information. Although it is conducted by AMSOIL, there are two affidavits at the end stating that all the information in it is correct. I think that says a lot. It's a lot of reading also. It's comparing API GL-5 75W-90 oils. There are some API GL-5 80W90 oil in there as well.

http://www.synthetic-oil-tech.com/Ge...te%20Paper.pdf


Makes me want to re-think my gear oil choices.

 

Thank you - very good read. Amsoil is an excellent product, but I have been pretty happy with my choice of Redline gear lube and manual trany fluids and will most likely continue to use them. Also keep in mind that this report is now 4-1//2 years old and chemists/engineers are always making changes/adjustments to their formulations to improve their product's performance.