Date:         Fri, 6 Oct 95 16:55:34 EDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         John Anderson <ja@coe.wvu.edu>
Subject:      Re: Splitfire plugs

A little interjection about these, platinums, three electrode
Bosch, etc.  I read an extensive article a few years back
written by Dr. Jacobs, the guy with the Jacobs Electronics
ignition parts company, which was probably mostly correct
as it makes good sense.  These things are not entirely snake oil
they have a place and reason why they work.  The only place
one really sees a gain in power or mileage with such plugs is
on older cars with aging ignition systems,  his logic was that
no matter the techniche, multiple electrode (Splitfire, 3 electrode)
or sharper pointier electrode (Platinums) the effect is the same
it takes less effort for the spark to jump because there are either
more surfaces to jump to and from or because sharper surfaces let
sparks jump easier (why you should file a plug square when regapping).
Now platinums might also has some improved durability but that is
another matter.  His point was say your worn coil and wires missed
5 out of 100 firings at higher rpms where the coil is taxed to charge
and fire, well if it takes less voltage to fire the sharper plug,
voila less misses maybe 1 out of 100, and hence more power, more
mileage.  Furthermore some empirical evidence, put Standard Bosch
Platinums in my '89 Jetta, and '86 Quantum 4wd, when I owned em, never
an improvement in mileage or power over standard Bosch Super or the
3 electrode jobs that were in the Quantum.  In the Corrado which comes
facctory equiped with an evil $16 EACH Bosch surface gap plug (you
got to see one to know what it is) PO had replaced with Bosch Silvers
at 30,000 not realizing surface gap plug good to 60k.  Dealer sold him
the Silvers for $8 so he was happy (a rip off dealer also wants $20 each
for the required plugs), terrified I put back in the surface gaps,
when I bought the car to the tune of $60, no change, for the hell of
it put in some regular parts store Platinums $1.80 each, no change
and I ran each set like 5000 miles recording the mileage and doing
occasional rolling time trials in gear.  Eventually did put the correct
surface gap plugs back in, now this was all highly seat of the pants
plenty o error but my point is, you are not going to see the difference,
EXCEPT, put a set of Platinums in the '76 before I sold it, had recent
regular Bosh Supers in it, less than 5000 miles on em, immediately
mileage increased from 18-20 to 21-23, and I know from current owner it
is still there.  The car had new Bosch wires for both sets of plugs,
nothing else changed, only to the Platinums.  Blew my mind, corse
'76 coil probably was not like new, hence my rec, for our aging beasts
go pay the extra $.50 for the Bosch platinums or other brand, any more
seems ridiculous.

John
ja@coe.wvu.edu
'78 Westy Virginia (even Platinums aren't solvin her miss)