Originally Posted by JCL

I think that is a very reasonable approach, to continue with the fluid that worked for you. My only caution would be that without a spec to conform to, any fluid is subject to changes from time to time and the fluid you buy one year may be different than what you buy a year later. Oil companies are pretty famous for changing their fluids in the interests of marketing, usually calling it reformulation. What the spec does is provide some comfort that there is a standardized fluid being offered.