I've been using Amsoil for about 25 years and use it in everything I own. Check out Project Farm on Youtube, he just did a motor oil shootout with about 16 different synthetic oils and Amsoil dusted them off.
Mobil1 is fine also. Amsoil is 90% marketing in my opinion. The various tests that support it are not scientific real world tests. Everyone has an opinion on oil. Whatever you choose, it's not likely going to alter the life of your Altima as long as you maintain it.