I have switched to a 0W-30 Major Brand Top Tier 100% Fully all Synthetic Oil for better fuel economy,quicker oil lubrication at start up, more piston ,Ring, and Piston Skirt, and lifters and cam lobes lubrication and protection. Lubricates tighter tollerences . I checked with all as Mobil1,AMSOIL,Castrol,and a few others on my 2013 4.0 V6 Toyota Tacoma PreRunner DCLB A.T. and all say it is safe and better to use than 5W-30 and 10W-30 Synthetics Oils ! Quicker cold start and faster lube in hot enviroments. Try it out and check with Oil Manufacturers also!