The October 8/9, 1966 Pacific Raceways race program held quite a surprise for me.
This CASTROL oil World Championship ad is well known to all of us, but 3 pages in front of it is this BARDAHL oil ad!
I had never even seen the BARDAHL ad before, and was astonished that it was in the same issue as the CASTROL ad:
(http://www.saacforum.com/gallery/52-291218181504.jpeg)
(http://www.saacforum.com/gallery/52-291218181342.jpeg)
I wonder how much, if any, Bardahl was added to the cars by SA.
Maybe the same one teaspoon that Granatelli supposedly added of STP to his race cars?
I'm guessing "none at all."