Well, it isn't scientific, but I ran my Rabbit and Lori's Golf on
Super Shell, that's RU-2000 (92 octane) and I got 209,000 miles on the
original bottom end of the Rabbit and 120,000 on the head VW replaced for
leaking seals. Lori's car went 117,000 with no problems in the engine
what so ever.

	Cost of ownership, per mile, of even old busses, isn't solely
gas. The 87 octane stuff, IMHO, is a commodity product blended for a low
price. The 89 and 92 octane products are less prone to detonation, have
cleanlyness promoting additives, etc. 

	I figure gasoline is like most things- if there's a modest difference
in price, the manufacturer is very often selling a markedly better product
for the small increment. This sure holds true for food (Compare cheap
peanut butter to good stuff, or cheap vegetables to good organics...).
The bottom of any market is price driven, and the top is features and
customer relations driven. VWs were never the cheapest cars to buy
or to own, although they were arguably the best buy for many years.

	Bill