I've been wondering the same thing...no matter how empty I have let my tank go,
I have never been able to use up that 'reserve' 2.5 gallons.  Maybe my tank is
dented? ...not sure, but I decided I dont want to find out...all I can imagine
is kicking up 15 years worth of Crap at the bottom of the tank to do it and
inviting more problems.  good luck
-gina

Brent Christensen wrote:

> I'm finally getting around to posting this, though it has always been a
> mystery to me...
>
> (I'm working from memory here, so forgive me if I am a bit off)  The owners
> manual for my '89 Syncro Westy indicates a fuel tank capacity of 18.5 gals,
> and a "reserve capacity" of 2.5 gals.
>
> I have *never* been able to put more than about 14.5 gals  into it (and yes,
> it does read full afterwards).  On Friday, I let the needle get deep into
> the "red" zone before I had a chance to fill up, and guess what?  15 gallons
> was all it took!
>
> So my question is, when they say "2.5 gallon reserve capacity" are they
> talking about a "hidden" 2.5 gallons that is still left even when the needle
> shows dead-empty?
>
> I am going to drive around with a 2 gallon can of gas until I run out,
> unless someone can help me unravel this mystery...
>
> Brent Christensen
> '89 GL Syncro Westy
> Santa Barbara, CA