Some people can make syn work for them and some people don't go through the effort and usually it may not be worth the effort The main advantages of syn oils are extreme cold ,extreme high oil temps and extended drain intervals. Does it prolong your engine life? Maybe maybe not. If you don't extend your oil change intervals ,live in an area with near arctic winters you may not gain any advantage with syn base oils. I have worked in fleet maintenance and seen engines with more miles on them than could be imagines by running quality dino oils and proper oil change intervals. Amsoil is a fine oil as there are other fine oils.I don't sell Amsoil . All I can say is if you want to give Amsoil a try, go for it. Remember since most properly maintained engines usually outlast the chassis or the expensive trannie rebuild I find the syn advantage next to 0 unless extended oil change intervals are used.