Way back IIRC around 71 or 72? Mobil came out with the new Mobil One in the silver metal can. It came in only one grade (5W20) and I began using it in my 69 Caddy Coupe Deville with the big 472 V8, I used it in my BMW R60/6 motorcycle, my buddy used it in his 70 Camaro V8, and his 66 Triumph 650...