Date:         Fri, 9 Sep 2005 20:50:48 -0500
Reply-To:     Joel Walker <jwalker17@EARTHLINK.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Joel Walker <jwalker17@EARTHLINK.NET>
Subject:      Re: gas mileage
Content-Type: text/plain; format=flowed; charset="Windows-1252";
              reply-type=original

>I took the recent suggestions on the list regarding improving one's
>gas
> mileage.  I aired all the tires to the proper psi, slowed down to 60
> (occasionally 65), and have quit downshifting to come to a stop.  I
> have
> always used the gears to slow down and I'm not sure how it helps to
> just
> use the clutch and brake.  Does it have to do with disengaging the
> gears
> and not putting torque on the engine?  I know my ignorance is
> probably
> showing again, but oh well.  At any rate, I am up to 21 or 22 mpg
> (previously 18 to 20).

in the digital fuel injection, both Digijet (which you have) and the
Digifant (of the 86-91 buses), it's more a question of taking your
foot off the gas ... that triggers the throttle-position switch, which
signals the computer to shut off the fuel injectors completely ...that
is, NO gas going to the engine. no gas = no unburned fuel = better
emissions. but it also means no wasted gas, so better mpg. :)

first time i knew about it was in an 86 bus that i had put a trip
computer into. the trip computer was hooked up to a fuel injector
wire, so it could count the number of times the injector 'fired' and
figure out how much gas i'd used (had to calibrate it over a tankful).
so i've got the trip computer set on instantaneous mpg and am cruising
down the byways and pull over to take an exit, taking my foot off  the
gas pedal. suddenly, the instantaneous mpg being displayed started
climbing!!! 60, 90, 200, 600, 900!!!! freaked me out. so i went back
to read the digifant fixit manual and there it was:
Fuel shut-off on deceleration
   has been added as an auxiliary function of the ECU for improved
emissions and fuel economy.

More Than Your Really Wanted to Know. ;)
joel