Lots of USA Harley riders rate this stuff, thought I would give it a try as my current oil also bought from Opie Oils "Amsoil Transmission Oil" seems somewhat lackluster at helping address harleys clunky gearbox. Gearchanging on these machines is brutal, the Redline is thick and pink and immediately noticed a difference, gearbox went from a clang in first to a more smoothed out clunk, gearchanges are also similar smoother clunks and the changes seem less brutal. Bike has an Ezi Shift and custom PTFE lined rod end/heim joints. I will add I tried to use as specified and ended up using the entire quart just like the last change. Bike is a 2022/23 M8 Softail Street Bob FXBBS.