OK heres my two cents. Ive seen the results of Mobile 1 in a 380 SL with over 150K cross hatch still visiable. and this guy only change the filter and added oil (maybe why the timing chain let go so early) . I subscribe to the theory of if you change it on regular intervals you cant go wrong. I use mobile 1 in my truck, and Shell Rotella in my 300D, but considering some of the other post I am considering a change to castrol or mobile 1. My intervals are 5to7K on the truck and 5K even on the 300D. Ofcourse the Harley uses H.D. 20w50 at every 5K. For what it's worth.
99 Harley Davidson Ultra Classic
97 Dodge Ram 1500
auto\hydraulic mechanic 20 yrs
[This message has been edited by shoe (edited 08-01-2000).]