I need some help deciding on oil. I want to get one synthetic that I can use year-round in everything from high HP tractors to pick-ups to small gas engines. I had planned to switch everything to Rotella 5W-40 syn, but the price has really gone up! The specs look pretty good for the Amsoil and the total cost is $0.40/gal cheaper. I have not really found any good reason to not go with this oil, but I'm open to suggestions/opinions. Thanks for any guidance!