What is your favorite motor oil? And what is your least favorite motor oil? Of the oils I have tried, I like Chevron the best for a conventional motor oil. In many vehicles over the years I have tried quite a few conventional motor oils, and Chevron stands out for me. I have not tried too many synthetic oils, but Mobil 1 10W-30 ran great in my cars. I tried an Amsoil oil but it was not a fair test, because it was one of the 7500 mile Amsoil oils. I have never tried Redline, so I can't say anything about it. I would probably give the German Castrol a try if I could find it. Of all the oil supplements I have tested, nothing seems to compare with Auto-RX. One of the few additives anybody should put in their motor oil.