New-York tribune., 1922-03-05
= By II. Clifford Brokaw
Technical Director, West Side y. NJ

Iechnscot Dsrect0r, West Side y. NJ.
G. A. Automobile Schools
A man has certain amount of power
when it comes to lifting objects Some
men have more than others. But any
person by systematic training of GER
tain muscles man increase his lifting
power somewhat. A gallon of gaso-
line has certain amount of power in
1T. When put into an automobile it
will carry the car certain number of
miles. But II the car is kept in the
pink of condition in every respect the
gallon of gasoline will be able to ac-
complish greater results than if it is
neglected.
Under very good conditions about
80 per cent of the power in gallon
of gasoline is lost in the engine. After
this thermal or heat loss is accounted
for there remains about 20 per
cent of power left. And most of this
is lost in the mechanical deyices of the
car. II the automobile is we'll tuned
the driver is apt to have from S to 6
per cent of power left for speeding up
or climbing hills.
When the driver comes to a stiff
Hill And is unable to get his car up
the steep grade the reason is apt to
be that he has some trouble that is
using up more power than should be
consumed Consequently, he hasn't
enough in reserve to get over the hill
ahead of him. When a driver is unable
to go ahead on al ordinary country
road on high speed and has to shift
into second speed to make any prog
ress. the reason is apt to be found in
the same sort of power losses.
Mechanical Losses
Outside of the 80 per cent therma al
and frictional losses in the engine
there are the mechanical losses in the
balance Of the working parts that use
up about is per cent more. The main
mechanical losses include losses in the
transmission gearing, in the universal
joints on the propeller shaft, in the
gears and bearings in the rear axles,
in the tires and in the wind resist
ance.
The loss of power in the transmits
sion gears, through the gears them
selves, the bearings on which the gears
revolve and their lubricant, is esti-
mated to average about Il, per cent
The loss through the bearings has
been made slightly lower than was
formerly the case because of the use
of ball or roller bearings, which are
now used in most instances.
Whenever gear reduction is employed
there is a loss of power through the
gears. This is the reason that the
speed which is used most is made the
direct drive. In this case there is no
gear reduction and therefore no loss
through the gears. On reverse speed
and on first and second speeds gearing
is employed, with its consequent loss
of power, but this does not apply to
third speed, which is used most Of the
time. In some cases where a very
high speed is desired fourth speed
through gearing is employed, but still
retaining the direct drive on third
speed.
Transmission Losses
In the transmission there are also
losses in power on account of the lubri-
cant which must necessarily be used.
The higher the speed the greater the
loss and the heavier the lubricant the
greater the loss. On the amount Of
amount of power that is lost. The
larger the amount the greater the loss.
That is to say, the lubricant should be
carried no higher in the gear case than
just touching the under side Of the
shaft on which the gears are mounted.
This is just sufficient to allow the gears
to dip into the oil and throw it around.
thus giving ample fabrication to all
parts. If more than this amount of oil
is carried it means there is simply that
surplus to be displayed by the gears,
with the consequent loss or absorption
of power.
Some manufacturers recommend light
oil in the transmission case, so as to
reduce the loss in power. The COM
promise between the loss of power and
effective fabrication would indicate a
very light grease and just enough to
sure good fabrication. Many transmits
sion cases leak a little, especially if
light oil is used, and need therefore to