Evening star., 1926-09-05

torist who saves a little gas by 5
forms an acquaintance with cert;
iustment which might otherwise
The matter of speed in relat
interesting instance to illustrate
little about economy-how to eff
duce-hc may operate the car tt
pr above the economical speed of
TO know that when car is being
it is running at its easiest speed
which it will wear longer and gi
Every owner has to discover the
economical speed of his car for him
self. and in doing this he will find that
1t varies for road conditions. tempera-
ture, weather, load. grade of gasoline
and conditions of the car itself 1t is
not something that can be ascertained
IN minute, but there are a few gen
eral rules to go by, SO that if the
owner does not find the exact eco
nomical speed every time he can en-
Joy the advantages of approXimating
Il.
Many Best at %.
Fifteen miles an hour used to he
considered the average economical
speed for the average car. but that
was in the days of rOugher roads.
open cars. uncontrolled springs and
hiGh-pressure tires. Just one newer
development, the streamlined, closed
body, has completely changed the pic
ture. A.closed car. other than one in
the so-Called pony" class, would be
dragging at Is miles an hour thereby
consuming more gas than is neces-
sary. Nowadays siX-cylinder car.
powered by any motor of so or more
horsepower and equipped with semi
automatic advance, is not likely to
reach it's normal economical running
speed until the speedometer registers
81.
There is a handy test for the ap-
rroXimate economical speed and
one which should help the mo-
torist find this speed for any given
conditions. All he has to do is note
the greatest speed at which the car
will run with the least throttle open
ing. This Is known as the throttle
test and is the sort of a test q driver
can make at any time during his driv-
ing.
When a car is dragging in high
gear it is necessary to open the throt-
tie wider than for the cars rolling
speed. This is exaggerated in the
case of hill climbing. Likewise. in or
DER TO force the car above it's rolling
speed the throttle must be opened
wider and wider.
While riding along the driver should
let off on the gas until he finds
throttle position at which the car con.
tinues to roll along at the same easy
gait. That is the practical, economi-
cal speed for the given conditions.
The scientific tests of course, calls for
actual measurement of gas consumed
and comparison, but this is not practi-
cal for everyday motoring.
Time to Shift Important.
Vow consider a more complicated
phase of the subject: Finding the
economical speed in hill climbing. Ow-
ing to the advantage of momentum
in hill climbing, it Is obvious that the
car should be accelerated as much as
possible without crowding the motor.
when approaching the hill, hut there
are other points not so obvious. One
Of these concerns the question rs to
when to shift to second gear, if at ALL
Here economy leads the motoriSt to
a. more intimate acquaintance with
his car. He may know that the en-
gine can be strained by forcing it to
pun the car all the way up a steep
hin in high gear: likewise. he may ap-
preciate that unnecessary dropping
back to second gear represents eXces.
stve wear on the transmission and
clutch, and frequently on the engine
IS well. But he is not likely TO know.
unless he has delved into the economy
feature OF it. that a legitimate shift
down to second gear Is often turned
into n loss by reason of the inexpert
way in which il is done.
Here is the way a typical driver
shifted down" the other day on a
steep hill.
For several seconds after it became
apparent that the engine would not
pull the grade in high gear ne kept
feeding the cylinders more gas than
they could comfortably handle, thus
causing bearing and p.ston pin wear
through excessive hammerinS in the
cylinders. In finally shifting he al
lowed the car to slow down to about
five miles an hour. and it was evident
that the engine was laboring even in
second gear. However. he assumed
that an engine should be thankful for
being given the assistance of second
gear. imagining that everything was
All right, when, as a matter OF fact.
everything was working TO the cars
disadvantage. The car Travelled over
100 feet before 1t accelerated to
speed where the engine was running
comfortably.
On this same hin a more expert
enced driver proceeded as follows:
Noting that the grade of the hill
vas about to exceed the cars capabili-
lies he made a quiclo shift to second
while the machine was running at 20
miles an hour. There was a slight
loss of speed during the shift, but not
enough to occasion any strain on the
engine when it was imparting power
again in the new gear combination.
Far less gasoline was consumed in the
climb under these conditions. and il
ls obvious that the car was greatly
benefited. There was no hammering
on the pistons. no strain on the con
meeting rod bearings and pressure on
the gear teeth was at no time eX-
Cessive.
1t is the false econmy of trying to
make every hin in high gear. and Of
running too slowly in second gear
when forced 10 drop down. that helps
10 cause so much clutch trouble. Few
drivers realize that the more momen-
flm there is stored llp In the ear and