I haven't been impressed with the Amsoil and since the price is better on the Rotella and Valvoline I'm switching back. Don't expect to get better than 7k out of the Amsoil......
Has anybody tried the Mobil 1 5w-40 oil yet? It's about 6 something a quart up here, so I'm looking at $100 in just oil.. I run it in everything else I have, but this is a bit steep, compaired to $60 in Rotella...