I used Amsoil in my 2000 Chevy 3/4 ton. I worked with a guy who was a part time dealer, and he offered me a free oil change to try plus sponsorship for the derby cars. At 6,000 miles I sent in an oil sample for analysis, and it came back clean. The truck had 189,000 miles on it when traded in, with no engine or transmission work ever needed. Good stuff in my opinion.