[Vwdiesel] New to list

[Scott Kair]

    Welcome to the list, Doug.
    Fuel economy varies, as has been pointed out, due to injection timing
and pump setting.  A couple of other variables include transmission code,
filling technique, use or non-use of fuel additive, and fuel quality.
    VW used a number of transmissions with various ratios, some of which
yielded better economy than others.  Roger Brown, one of our listees,
maintains a substantial website which includes a page breaking down the
transmission codes by gear and final drive ratio.  (Unfortunately, I don't
have the URL close to handy.) It might be worth considering that speed
limits were lower when most of the 1.6 L engines were built, so the
transmissions were geared for optimal economy at speeds that would get us
run over today.
    Diesel fuel foams like beer when filling, and requires a bit of time to
get the tank completely full.  It may sound elementary, but I can usually
get at least an extra gallon in the tank after the handle first shuts off.
I've also had suspicions about how scrupulous a set of records are kept by
those who claim 45-50 mpg for in-town driving.
    Some have noted apparent gains in economy through the use of various
fuel additives, but that can be opening a can of worms here. :)  Hagar noted
that it might be prudent to look into the issue due to possible pump seal
issues with CA fuel.  This might be worth pursuing as a preventive.
Stanadyne Performance Additive isn't the universal choice, but does seem to
keep pump seals happy.
    Fuel quality varies greatly.  Lower cetane is lower energy content and
thus lower economy.  Depending on CA's labelling laws, premium Diesel might
be something to try, if the cetane rating is posted at the pump- Amoco used
to market a 50 cetane premium that some people swore by. It's also prudent
to keep an eye on various stations and buy where the turnover seems to be
highest.  Here in Illinois, fuel isn't always rated, and I've measured the
low-bid garbage at work at around 34.  In some areas, bioDiesel blends are
available to boost cetane, but as in all cases, it boils down to what's cost
effective for you.
    I've had a  few tanks average to 45 mpg., but they've been few and far
between, with almost all the driving on highways at slightly below 70mph.
For mixed town and highway, slightly below 40 is closer to average, except
in winter, when it drops to around 32.  An average of 35 at 85 mph wouldn't
be surprising.
    HTH,
    Scott Kair
    92 Jetta ECO