Valvoline racing oil is the 1st racing oil I ever used and might have been the 1st racing oil sold in my area. Over 40 yrs. ago I had used regular Penzoil in my '64 Olds Cutlass when the Valvoline racing oil was introduced. Back then they sold chemicals to add just before an oil change when changing oil brands. I used it, made the switch, but afterward, my engine started burning oil. I always attributed the oil consumption to the flushing chemical & not Valvoline.
Here's a bulletin issued by Valvoline this past June that contains some interesting information regarding zinc:
