Reduced gear oil temperatures and an optimum performance level. Castrol MTX Full Synthetic 75W-140 offers a high standard of safety, even under extreme operating conditions and also has a noise dampening effect in the drivetrain due to its viscosity level. Excellent wear protection even under extreme loads. Castrol MTX Full Synthetic is a fully synthetic transmission lubricant developed for all high performance motorcycles that have a manual transmission with a separate oil balance.. Excellent gear shiftability – Low foaming tendency, especially.