Forget the brands and the whatever else. Look at the specs. The AX-15 as far as I know, requires a GL-4 oil. They don't work for shit with a GL-5 oil. Mine had some unknown stuff in it when I bought it...likely GL-5 because it didn't shift for shit, so I replaced with it a GL-4 oil....I used Amsoil, because it was on the shelf at my local parts house. If redline was there, I would have used that...but the brand DOES NOT MATTER, as long as the product meets the specification. After putting 100 30 or so miles on my shitbox with the new gear oil...damn thing shifts like butter...wife even stopped complaining about it. I used to road race a VW and had a pile of very stout (relatively speaking) 020 transmissions with different gear ratios...all of which were gone through after every track day because I was told they were the weak link....they needed a GL-4 oil, and I ran redline, because it was free at the time. Then when it started costing money, some guy gave me a 5 gallon bucket of no name GL-4 oil so I started using that...it worked just as well. Ignore the name on the front of the bottle, pay attention to the specs listed on the back of the bottle...that's the important info and the only info that matters.