Evening star., 1926-09-05

the car. lie could not be expected
, operated atits economical speed
. which is obviously the speed at
We less trouble.
! work the less strain there is on the
! clutch plates and bearings. With the
engine straining to pull and the car
holding back, the clutch unit is bound
to suffer. Plates warp. perhaps burn
out. If nothing worse, friction is gen
Grated. and friction is waste. Besides,
there is the possible damage to the
clutch parts through rusting. due, in
| turn, to condensation when the over
| heated clutch cools off.
Very rapidly engineers are coming
! to recognize the part that the momen-
| tum of gases plays in engine perform
ance and gasoline economy. 1t is some
times difficult for the motorist to pic
ture an invisible unit of gas as hav
| ing momentum. yet that is the Situa
| ton. The momentum of the gas and
of the raw gasoline molecules, which
are also present in low operating tenn
| peratureS. is constantly varying, ac
| Cording to the speed of the pistonS.
, Going back still farther, it may be said
that for all practical purposes the mo-
mentum of the gas is controlled by
the driver when he operates the ac-
celerator.
Suppose he steps on the gas sud
denly. What happens? The gas de-
velops a terrific speed, forcing the gas
ahead of it to it's destination in the
| cylinders and pulling. through suction,
| the gas that is behind it. Naturally
when the driver takes his foot off the
| accelerator. automatically closing the
throttle and blocking the way between
carburetor and intake manifold, there
Ir !, i.,1 i,,f 70
| intake. The next minute he sees a
chance TO pass another car, steps on
| the accelerator again, but finds the
engine giving an unexpected gasp
The engine has simply struck the air
pocket or dead spot. It is only an in
stantaneous gasp for gas, but it serves
to retari the engine, waste momentum
and, worst of all. intiict a little more
wear on the moving parts involved.
One OF the first rules of economy in
driving is IN feeding gas progressively.
and the interesting part about 1t is
that it is also one OF the first rules for
saving repairs and troubles.
Many motorists learn that 1t does
not always pay to try to save gas.
This is quite as important as knowing
what forms o. gas economy lead to
the more important economies, such as
freedom from trouble, efficient per-
car owners have made the mistake of
confusing lean mixture with true
economy, and Of late there has been
tendency to coast too much at the
wrong time. This can be traced to the
easy clutches with which the majority
Of cars are now equipped. 1t requires
so little effort to hold out the clutch
when descending a hill and the four
wheel brakes are so effective and
secure.
Springs May BE Injured.
In many instances the greater case
of these newer clutches has been ef-
fected through pairing down the ten
sion of the clutch springs. In some
types of clutches there is very little
provision for clutch spring tension
loss, which means that il the driver
coasts excessively the spring tension
suffers and the clutch gets to slip
ping. The great increase in traffic
congestion necessitating as it does so
much gear shifting and depressing OF
the clutch pedal. provides for about as
much spring compression as the
clutch springs should have for their
own good To ride down the hills
with the clutch held down simply
means sacrificing anything that may
seem to be gained by the process.
There is no real economy in trading
gallon of gas for repair Dill.
Economy can lead to freedom from re-
pairs or make the repair shop desti-
nation. The motoriSt chooses.
For instance, if it is seen that the
car must be stopped at the next in
tersection. and if a stop could be made
several hundred feet ahead without
placing too much reliance upon the
brakes. what is wrong with coasting
to the corner? The clutch springs can
be saved by shifting to neutral, thus
making it unnecessary to depresS the
clutch pedal for the entire length of
the coast This method will help save
gas. will slow down the speed of the
engine when it is not needed and will
serve to compensate for those situa-
tons when coastinG would save gas
but burn out brake lining.
If economy, carefully thought out,
can lead to a better acquaintance with
the car, it is obvious that the reverse
is also true. Some car owners may
he able to make more progress by re-
VerSing the order suggested in this
article. Sometimes it is safer than
the usual way. When the mileage of
the car jumps from Is to u miles to
the gallon there may be grounds for
suspicion. Perhaps the motorist would
have found it more practical to be
content with u mileage of l3 had he
reversed the process and discovered
that the increase could be had by rum
ming with the tires pumped up to a
dangerous pressure and the carbu-
rotor mixture leaned down to such a
point that there was danger Of stall
ing when the clutch was pressed out.
In any event, economy always can
be more than a mere saving. even II
il turns out 10 be the wrong kind of
economy. Remember. there is the
new and better car TO think of. Many
a motorist is now reaplng the rewards
OF lessons learned with his first car.
,CoDyriGht. 1920