i'm most interested in the viscosity and overall properties - atf, +4 +f, dexron, mercon, etc. is the difference just friction modifiers? i'm well aware of usage per recommended in owners manual for cars/trucks -i own a dodge :) . i'm more interested in which works best in clutches/transmissions for 2t bikes.....modern and vintage.. i'm already using atf+f in some bikes, and it works fine, just wondering if there is a 'best' formulation.... and any drawbacks to using atf? it's dirt cheap - i switched from amsoil 0w-40 in my gasgas to atf, and it's working great so far. i'm changing atf every 2-3 hours, so i'm most interested in what works best during this limited (albeit difficult) lifespan..