Vavoline VR1 20W50 Racing Oil

I run straight 30W Valvoline Racing in the summer, and Valvoline Racing 20W-50W in winter. From the "66" 273 Barracuda to the "96" ACR Neon. I change it every 3,000 miles. I have 250,000 miles on 2 or 3 cars with engines running almost like new. Both the Chrysler and Chevrolet racing manuals say, for increased life use straight 30W oil. I will not change my mind. My system works. Y'all make your own decisions.