Ken is right on.
I have owned a few low mileage auto Carats and they all had better gas mileage at 55-60mph, over that and the mileage would suffer.
I am still looking for a mint 91 Carat in Tornado Red with a 4 speed.

dylan

----- Original Message ----
From: Kenneth Wilford <kenwilfy@COMCAST.NET>
To: vanagon@GERRY.VANAGON.COM
Sent: Monday, December 3, 2007 11:37:40 AM
Subject: Re: Poor mileage update

I am glad Mike and other list members are talking about the mileage
issue because I have been thinking about it for a while.

I had concerns about my 90 Carat and my 91 Carat Vanagons.  I replaced
both motors with rebuilt ones in the last year or so.  I have all new
ignition components, fuel injectors cleaned, new oxygen sensor, new
exhaust systems, and they both run great.   However around town I was
getting 16-17 mpg and on the highway about the same.  I thought that
mileage would improve after the new work but so far it hasn't.  The old
engine in the 90 had almost 300k original miles on it and the
 thermostat
was open constantly (heat was very poor in the winter).  Now I have a
brand new 87 deg (correct) thermostat puts the temp at the proper level
and I have great heat now, yet fuel mileage is still the same.

I recently took a trip from NJ to GA and back again and on the return
trip I recorded my mileage numbers.  I was driving the speed limit the
whole way with cruise control on most of the way.  65-70 mph.  I got
around 17 mpg the whole trip until I got back to NJ.  I drove about
forty miles here at 50-55 mph.  My mileage went up to almost 19mpg!  So
I think the main factor for me is speed.  With an automatic
 transmission
Vanagon at 65-70 mph you are seeing some pretty high rpms (a little
above the green zone on the tach).  However at 50-55 mph the tach is
reading around 3700 rpms which is the sweet spot for the fuel
injection/engine as far as mileage goes.  So what I think is going on
 is
that back when the vans were made the speed limit was 55 mph everywhere
in the US.  They were designed for that.  Today the speed limit has
increased and but the sweet spot can't also be easily moved.  So if you
were doing 55 mph all day long you would probably see 20 mpg.  If you
are going faster your mpg is going to go down.

I have 15" rims on the 91 and I am thinking about going to larger tires
the next time I replace them (soon).  Anyone have any input on how much
larger I would have to go to see an increase in mpg?  Or if this will
 do
anything at all?

Thanks,
Ken Wilford
John 3:16
www.vanagain.com

Michael Elliott wrote:
> Hi Scott, thanks for the detailed list o' ideas and knowledge!
>
> On 12/2/2007 1:55 PM Scott Daniel - Shazam wrote:
>
>> Is it running warmly enough ?
>
> You read my post of yesterday? About maybe a funky thermostat? Well,
 that
> applies only to this last trip, prior to that, with the old
 thermostat I
> was pushing to the right of the LED lamp in the center of the temp
 gauge.
> I was getting 15.5 mpg highway then.
>
>> 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.
>
> I'm not at all certain why the Famous Online Vendor decided to sell
 me a
> cooler thermostat.
>
>>   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.
>
> Yup. I have a stock 1600 in my 71, and the similarities are striking.
> Except for all the tubing and hoses on the 1.9L, and those odd covers
> over
> the cylinders!
>
>>   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.
>
> Me? Did I suggest I was looking for some magical increase in mileage?
 I
> wasn't looking for any 40% improvement, I just want to get my mileage
 up
> to what others with the same engine and transmission report. Did you
 see
> my article on the wiki (as noted in my post below)? Quite a few
 people
> responded, and my mileage suck(ed) big time. I'm edging closer to the
> middle of the pack now.
>
> [long bit about knock sensor not applicable to WBX engine snipped]
>
> ... > 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.  )
>
> Checked it, yup. Thanks.
>
>>  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.
>
> Beyond my skillset and toolset.
>
>>   Also engine condition.......if compression is lowish .....you just
>> can't
>> get around that. Tire pressure ?
>> I sure hope you have nothing on the roof.
>
> Thanks, it's all on my blog at
> http://camping.elliott.googlepages.com/poormileage
>
> [snip]
>
>>   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 !!
>
> Thanks. I reckon I'll take this as far as time and my small
 collection of
> Harbor Freight tools will take me. The mileage is slowly improving as
 I
> check things out. I'll see what it's like after the rear wheel
 cambers
> have been adjusted and if I'm running in the middle of the
 statistical
> pack I'll be satisfied.
>
> --
> 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
>>
>> -----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
>>
>