In my owners manuel It states 91 octane . That  is premium go juice. The p.o.
of my
86 GL used min 93 if not 94 SUNOCO. Still has original heads @ 186k on it.As
it was explained to me and i took the pleadge higher octane Lower combustion
temps,
higher milage and less ware on the componets hoses/seals do not dry out. I
know thatyou will not agree but I cannot argue the end result on this
vanagon.

Jim Morgan  86GL "Breadbox"