I use regular 87 octane on my 87 GL and it has worked fine.. (original owner, 120K miles..orig engine..no rebuilt yet!)

The only additive I truely believe in is Chevron Techron. It is already in Chevron gas but before every oil change I add a bottle of Techron concentrate in the gas and it really really works to clean the injectors and valves.  After every bottle of Techron additive, I get a few mpg higher then the average.  It must sell well too since I notice that our local Shell and BP gas stations carries this additive ..in it's original Chevron label bottle.  When I take my other car (Infiniti) to the dealer for any sort of work, they always put a bottle of Techron in the tank ..just for good measures.. I think in states where there are no Chevrons, Techron are sold under the Caltex brand.. it's the same thing.  
(I don't work for Chevon..in fact I went to graduate school on a Shell fellowship!)

Yau-Man Chan
87 GL

>>> David-M <dmc@CYBURBAN.COM> 09/14 10:39 AM >>>
I just read my water-cooled Vanagon owners manual and there is a quite
lengthy section on fuel requirements.
Do I understand correctly that 87 octane fuel is correct for this
vehicle?
Also, the manual goes to great length to talk about gasoline additives
and says that some brands are better than others in this respect, but of
course mentions no particuler brand.
Apparently the important factors are protection against carbon build-up
on intake valves, and keeping the fuel injectors clean.
Has anyone researched this subject and come up with the best brand of
gasoline for the Vanagon?