four stars five stars the very best oil on the market for synthetic oil you cannot 00 happy in my john deere z425 must have nothing better i bought this in combination with the royal purple oil ive used royal purple in just about every one on great oil five stars cant be all bad noticeably better than most engine oils oil maintains its color and protective film even after 6000 miles the best oil on the market for the everyday cartruck owner best oil on the market royal purple 061306pk apilicensed sae five stars impressive oil ive been using this since my second oil change great synthetic oil just really expensive convenient and great pirce