Date:         Thu, 8 Feb 2001 09:11:50 -0700
Reply-To:     Mark Keller <tyler@ISLANDNET.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark Keller <tyler@ISLANDNET.COM>
Subject:      Re: Poor Gas Milage
Content-Type: text/plain; charset=us-ascii

I may  regret starting this thread, but I do indeed get 19- 21 MPG with
my 91 automatic, and I have an adjustable fuel pressure regulator-- but
I do other things.

Tire pressure, I run them at 45 rear and 35 front. I basically feel the
tire argument can get so technical, but try to inflate the tires until I
feel the van is rolling down the road, and sidewall force is better than
average. Touchy feely I know. But again  tire inflation is a significant
influence on mileage.

Rolling resistance is a technical term, but not all tires roll equally.
I've felt that Michelins roll best.  My current Firestones don't roll
that well in my opinion.  My gas mileage is down 1 mpg with this set of
tires over my last set which were the PO's Republic somthings.

Weight.  It simply matters.  I keep my van empty.  The title says 3425l
bs.  I try to keep weight to a minimum.

The vacuum gauge.  If your serious about improving your fuel economy get
one. You'll be surprised at the value of this instrument.

Does your van set nose high? Greater aerodynamic drag
Do you make several startups on a tank of gas.  I.e. the fuel injections
runs rich until the Temp II kicks in.  I'm not sure what the time is to
cool the engine down, but I feel that at 15 min off in winter and temp
gauge is cold again, so the engine runs rich until the van warms up. BTW
my aftermarket TEMP II is slower than my VW brand Temp II was by a
couple of minutes at going into closed loop.  I feel this a stolen a
little economy from me.

I also run the Prolong in the xsm, diff, and engine.

I use a Gulf Coast submicronic filter system

I use synthetic oil.

All of the above contribute to keep internal friction at the lowest I
know how.

While I'm normally a touch above the speed limit up to 65 mph, I drive
the van easily.  I mange my momentum up and down hills,  I look well
ahead in traffic to avoid braking and accelerating unnecessarily.

since I have an automatic I keep my RPM above 3200, as much as possible
since the stall type torque convertor slips below this.

There, that's how I get 19- 21 MPG on a regular basis.  BTW my wife
doesn't do any of these things and the mileage sucks 17. something to
19. something when she drives.  I'd rather let the cruise control run;
which by the way eats gas too.   Only in a tailwind does a cruise seem
to be on par with a good driver for fuel economy.

Sincerely,

Mark Keller

As an addendum, this is minute, but next time you get your tires
balance, look at the roundness and runout of your rims and tires.  These
cause vibrations, and vibrations lower fuel economy.