"Max-Gear" from Royal Purple is an ideal gear lube for use in front or rear drive differentials, manual transmissions, or marine gear drives that specify the use of an API GL-5 or GL-4 fluid. It will provide maximum protection for heavily loaded gears and will outperform other gear oils by combining Royal Purple's proprietary "Synslide" additive with the highest quality synthetic oil available. It will help to maximize power and make your differential or gear drive run smoother and quieter. Royal Purple's "Max Gear" will reduce operating temperatures and help your dif go longer between overhauls.