Educate yourself. If you want some peace of mind, go to the 'used oil anlysis, gas engines' forum and do a search for 3.1 or 3100 V6, then look at some of the used oil analysis using 30 weights. I won't spoil it for you, but I don't think you will find those engines self-destructing on 30 weight. By the way, I have a Ford 3.0, an engine design that has not changed much since the 80's, that loves 5w20. Oops, I'm sorry, that's too thin, I guess my engine will explode tomorrow.