[Vwdiesel] Genset RPM and Diesels

[Area31 Research Facility]

Loren,

I can tell you that with no electrical load on the alternator if I spin the
engine at 1200 RPM I get much longer run time on a litre of fuel than if I
'idle' it at 1800 RPM.  The throttle is open just a hair above the idle stop
to do 1200 RPM, no load.  To do 1800 RPM no load it has to open about 1/8".
Add 4 kW electrical load at 1800 and the throttle opens further to about
1/4" (under governor control).

Now consider that I can load the engine lightly with an electrical load of
about 1500-2000 watts with the throttle open about 30 thou of an inch above
the idle stop (~1200 RPM).  The presence of the load does not increase the
fuel usage in this model. (no governor, fixed throttle setting) because the
throttle opening has not been increased.  Efficiency is low but fuel usage
is low also.

Rob

----- Original Message -----
From: <LBaird119 at aol.com>
To: <vwdiesel at vwfans.com>
Sent: Tuesday, May 24, 2005 1:46 AM
Subject: Re: [Vwdiesel] Genset RPM and Diesels


>   Just a thought on the higher fuel consumption at higher rpm thought.
> Seems logical however many of the early Rabbits got as good or better
> mileage with a 4 speed than a 5 speed.  Same as only driving the 5
> speed in 4th gear.  The difference is generally minimal.  In my personal
> experience in the 55mph days, I got 45 city and 40 highway with the
> 4 speed.  That was when I decided I needed a 5 speed.  It stabilized
> things a tad above 45mpg for the most part but mostly I gained a loss
> in cabin noise.
>      Loren
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