Zinc oil supplement

VR-1 Valvoline 10w-30 I buy 5 quarts from Summit Racing... Once a year fall oil change and a Wix filter. No Zinc additive added as it's already formulated with Zinc and they do not advise using any additives. It already has 1400 ppm Zinc and 1300 ppm Phosphorous (conventional formulation). Use it and forget it $8 a quart and it's cheaper than steel.