Evening star., 1926-03-07
BY WILLIAM ULLMAN.

What is the automobile fuel of the
future and when will it be adopted
generally? These are questions being
asked by many far-seeing motorists.
The answer, given by scientists. is,
tersely:
When motorists quit believing their
present engines are marvelS OF etfl'
cheney and demand something that ap-
proximates the marvellous potential
performance of the internal combus-
ton power plant for automobiles.
The first step in production of this
wonder food for engines is education
of the car owner. experts insist. He
must realize that the average auto
mobile utilizes but per cent of the
heat or mechanical power content OF
the gasoline it burns. These figures
offer an astonishing truth upon which
the motorist might well ponder.
This condition is due primarily to
the preponderant use of straiSht-run
gasoline which will not permit the
general adoption of higher and more
| efficient engine compressions. In the
average engine today, the pistons
| compress gas Vapor to about one
quarter of it's normal volume before
! ignition occurs. With the higher COM
preston advocated by engineers.
|
| efficiency and better gas mileage, the
to one-sixth before the explosion with
in the cylinder
Claims Not Mere Theory.
This is not theory. In the labora-
tory of experience. it has been proved.
| Higher compression engines have been
| built. They are in use today. They
! are productive of gasoline mileage
| figures of which most motorists mere
| ly dream. Unparalleled power comes
with the use of this improved design.
The question arises. Why is not this
| type Of engine universally used? The
answer lies in the fact that fuels that
suit this better power plant are not
we'll enough distributed. No one
wants to limit the range of his auto
mobile to the field covered by but one
or two filing stations. This might
easily be the situation in which one
would find ones self. however.
Such fuels are available but in no
way near the quantity to supply the
demand that would follow general
adoption of higher compression en-
gines by standard automobile makers.
| In the event such fuel was available
in sufficient quantity, there still would
be the problem of distribution.
Invariably, the question comes back
! to the motorist for an answer. He
wants greater power with more econ
omy. but he is far from aggressive in
his determination to get them. Until
| he backs up his ambitions with more
than words. the Straight-run gasoline
or some of the milder forms of the no
| knock variety probably will suffice.
| There is no shortage of this fuel.
scientific investigation shows. 1t is
| available and will be available so long
| AS the motorist registers no dissatis-
faction with it.
The automobile factories and re
fineries are waiting for the motorist' S
word Co
One thing is certain--the higher
compression power plant cannot he
used with ordinary gasoline. The
habit of this fuel to knock precludes
such possibility Knocking destroys
the advantages of higher compression
by straining the engine and retardins
the pistons. With fuels of the no
knock order. however. the presen
type of automobile engine can bt
operated with the spark farther ad
vanced, which means higher engine
speed and more power. Also, an &C
emulation of carbon which raise:
compression in an engine by cutting
down cylinder capacity will not cause
compression knock.
There is much mystery as to what
the knock really is. Its technical def
nition is detonation. Engineers an6
chemists. however. know how it car
be eliminated. and that is the bis
story Also they know that without
detonation higher compressions re
suit in increased power and much
| greater efficiency.
Detonation is fuel affair. lr
petroleum fuels such as Kerosene and
gasoline it is especially pronounced
i while In, slch flelS as alcohol and ben