Date:         Thu, 13 Mar 1997 15:05:45 -0500 (EST)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         SyncroHead@aol.com
Subject:      Re: Gasoline Grade?

In a message dated 97-03-13 13:57:59 EST, kfairey@oit.umass.edu (KENYON
FAIREY) writes:

> Gasoline grades also vary among brands and with elevation.

That's right.  At higher elevations, engines don't require as high an octane
number.

>  In my '91 Westy, standard trans, I averaged 20-22 mpg on 87 octane. While
>  out west this summer in dry, higher elevation areas, I found that 'regular
>  unleaded' was only 85 octane. Being VERY CAREFUL not to purchase any gas
>  that was "blended", as many of the midrange octanes were,

Why not "blended" gases?  All manufacturers I know of (I've done computer
controlled blending and additive systems for many) that have a midgrade fuel
create it by blending the premium with the regular.  There is nothing wrong
with this fuel.  The only difference is the amount of chemical used for
determining the octane number.  They can be proportionally blended to create
any octane number between the premium and the regular.  

Additives are added seperately from the blending process, so "terminals" (the
locations where gas trucks load up and gases are blended) can additize per
the particular gas flowing at the moment.  Typically in a given market,
several makers (Chevron, Texaco, Shell, etc) will fill their trucks at the
same terminal and the octane blend of gasoline is choosen on the spot (by
driver request) and the additives added per predetermined computer program
dependent on the grade of gasoline and the "brand" of the fuel.  Shell's
additive will be added to fuel going into shell trucks, etc.  Most
independent sellers of gas and some majors too use Chevron's "generic"
additive package, which is different than the recipe used for Chevron's own
gas stations.

Regards,
Jim Davis
87 GL Syncro
88 GL Wolfsburg

 I found that I 
>  actually got 22-25 mpg on the 85 octane! And the engine purred. On the way
>  back east, you could see the octane of the "regular unleaded" go up as you

>  lost elevation.
>  
>  I ran "regular unleaded" no matter what the octane on the entire 8500 mi 
> trip
>  with absolutely no problem. I plan to do the same in my "new" '91 Westy
when
>  I get her.
>