Date: Sun, 2 Dec 2007 13:55:16 -0800
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Poor mileage update
In-Reply-To: <475317A9.7080905@gmail.com>
Content-Type: text/plain; charset="US-ASCII"
Is it running warmly enough ?
You want it running as hot as you can get away with, especially in the
winter.
You should have the 87 degrees C thermostat,
And if someone sells one hotter, I'd try that.
Cooler is NOT better ! warmer is better.
At a FLAPS find out how hot some modern cars run, like what temp their
thermostat is - pretty far up there I think you'll find on some cars. They
also have far more evolved cooling systems designed with emissions and fuel
economy in mind in the first place, not a consideration on an 80's or 90's
something vanagon.
Combustion chamber design wise and all that, it's really an extremely
crude engine.
Some subaru 2.2 vanagon drivers report 22 - 24 on the highway, and one guy
claims 27. That engine is up to several decades more advanced than the
waterboxer engine is.
As far as I can tell, it's just a 1600 air-cooled design with bigger
displacement and 'adapted' ..crudely converted to a water cooled design.
I know you don't want to hear this, but there just are no real ways around
the limitations of the waterboxer engine in vanagons. Incremental
improvements, but no way to jump 40 % ahead I power, emissions, and fuel
economy.
I was disappointed my 85 weekender with auto trans and 2.1 waterboxer gets
16 mpg on the highway. I haven't tweaked the timing up, and I know it needs
an alignment. Waiting to get stiffer springs.
Just one small example of more modern technology .....knock sensor
ignition. Knock sensor ignition, which a waterboxer doesn't and can't have,
unless you can find or fit an aftermarket system, or adapt one from a more
modern car......tries to advance the timing as much as it can all the time,
and keeps the timing just below the knock threshold - just perfect. Can even
respond to higher octane fuel. In every case, electronics can do something
that mechanical systems can not. 2.1 waterboxers have electronic control of
the ignition curve , but it's not 'smart' since there's no knock sensor.
1.9 waterboxers depend on mechanical devices ( which CAN not have the right
timing curve anymore !!...did you check that !!!?? ....you could be 10
degrees short on timing advance at 3,500 rpm for all you know, if you
haven't check that. )
last thought, I'd try mid-grade fuel and see if that helps with fuel
mileage. You can advance the timing more too with higher octane. I have read
that you can have too advanced timing at high rpm, and thus very damaging
detonation, but not have pinging, so be careful. The whole timing curve
needs to be checked out carefully, at all rpm's and loads.
Also engine condition.......if compression is lowish .....you just can't
get around that.
Tire pressure ? you could run 60 psi on nitrogen with the right tires, for
example.
I sure hope you have nothing on the roof.
Weight in the vehicle, is only detrimental to mileage during acceleration
and climbing hills.
In cruise it doesn't matter, or going down hill.
I shut off coasting to a stop even. If automatic, I shut off in gear, THEN
put it in park
( be careful though, if you're trying to teach yourself this, 100,000
times the last 30 years doing it the old fashioned way, makes it hard for
most people to learn to put it in park after shutting off. But I shut that
sucker off absolutely as soon as possible, in all cases. If manual, before I
get it stopped, if auto the second it's not moving, THEN put it in park.
Shuts off easier that way too, being in gear, more load on the engine.
Brand of fuel - if you are using Arco, forget it. Use a higher quality
fuel. I've had bad Arco fuel for sure. It's always cheaper too. Has ethanol
in it or something like that.
I think you have a ways to go yet on sleuthing and changing tactics.
Poor fuel economy can be one of the very, very hardest things to fix in
car-dom. There are even factory new cars that get poor mileage compared to
similar models, and no one can figure it out. It can be the very most
elusive thing there is to fix. Keep going !!
Scott
www.turbovans.com
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Michael Elliott
Sent: Sunday, December 02, 2007 12:38 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Poor mileage update
I have been told that some of you are breathlessly anticipating the next
installment of this ongoing tale. I suspect that whoever told me that
greatly exaggerates how interesting this is, and is just messing with me.
But just in case there's some poor soul out there who can't find anything
more nourishing to read (like, even, porn), here is the latest:
Over the past two months I've looked at about everything I or anyone else
could think of which might explain why my 84 Westy's mileage sucks so
bad. See
http://vanagonwiki.net/index.php/Mileage for survey data showing typical
mileage for Vanagons,
and see my blog at
http://camping.elliott.googlepages.com/poormileage for info on my van's
mileage and the things I've looked at.
A good researcher would change only one thing at a time and see what
effect it has (if any) on mileage. But my van is not my daily driver, and
my "standard drive" (a 132-mile round trip up to 6,000 feet and back down)
occurs only once a month. Life's too short to try one thing at a time, so
I can't claim to show cause and effect with any confidence. Which makes me
a poor researcher. I can live with that. Results are what I want, man!
Of all the things I checked, I only changed two: advanced the timing a bit
(my threads about that are about a month old, look 'em up in the archives
if curious) and got the wheels aligned a couple weeks ago (except for the
camber of the rear wheels because the shop didn't know how, I'll have them
handle that in a week or so).
Prior to doing anything to the van, my city mileage was 11 mpg. Miserable.
My average highway mileage was 15.5 mpg, and my standard drive netted 16.7
mpg.
After the timing change (and some general cleanup of some issues that
don't appear to be related to mileage, like a failed coolant pressure
relief cap, a partially collapsed breather hose, and other minor
thingies), my city mileage seemed to improve, to about 13.7 mpg. The
engine seemed to have a little more "oomph."
After wheel alignment (save, as mentioned, the rear wheel cambers), city
mileage clocked in at 15.6 mpg. Steering felt "lighter" (i.e., easier).
I returned from my standard 132-mile drive yesterday morning (couldn't do
it in October on account of these fires that were chewing up the area; the
Forestry service closed all the national forests) and see that I got 17.9
mpg. I was also able to maintain speed on uphills where I previously
needed to downshift.
I'll be going up and back in December (if I can sort out a problem I had
up the with the engine starting) and will see what difference getting the
rear wheels aligned will do, although winter conditions might hide the
effect of that.
--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR
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