The Washington times., 1923-10-24
w by You Should
Shift Gears
By BARNEY oLDFIELD.


Regardless of how well car performs on high gear and
regardless of the desire Of the to drive high gear
wherever possible when the first second
speeds be used if the best and most economical
fOrmance is to be secured When hill is SO steep that the
will not climb it high gear the has choice
but shift into second first There point just short
Of this however, where it is better economy to climb NIL
for this and the appreciated them thoroughly ne
would be likely to shift his gears at the proper time
and enjoy the benefits Of longer life well the
economy in fuel which results.
When is climbing hill which it is just barely able
negotiate high gear the working much
serious disadvantage than the realizes Three
OF these disadvantages are very important They are
Excessive strain engine and propeng PARTS 2-Dsad
vantageous fuel and carbureting conditions and 3Dsad
vantageous lubricating conditions.
When you do not put your in second gear you are
asking the engine to do this work without the benefit Of
a reduction gear
mobile given hill at the rate Of six miles hour
horsepower $4,000 foot pounds minute twenty horse
power therefore would 100000 foot pounds per minute
Presenting that the engine turning this miles hour
speed at the rate of 300 revolutions per minute the crank
1900 foot pounds while travelling high gear.
Presume now that the shifted into second gear
requires the Same horsepower to pull the the hill
but the engine instead Of travelling 300 revolutions per min
ute will say travels $50 revolutions per minute The
number OF foot pounds per minute that is $780,
must be delivered through the cranksha but the crank
shaft revolving three times FAST the foot pounds there
revolution will be only onethird great whereas this
it is travelling $50 revolutions per minute foot
pounds per revolution would only be 1000 instead 1900
In this theoretical the stress the crankshaft only
half as great because of the increase in speed
If clutch is capable of delivering certain horsepower
deliver half that horsepower 500 revolutions per
In other words the capabilities of clutch measured in
terms Of torque also the capabilities propeller
shaft universal joints all of the axle parts and the
units which drive the The is keeping the torque
down by increasing the speed of these delivering
given horsepower He do this by using ntermed
ate gears There great who think that
everything highly stressed when it speeded up
possibly for this many avoid the their inter
mediate As the examples show this
opposite the truth The these parts are reduced
almost direct proportion to the speed which
Not only effected by reducing the stresses on
The
fuel will result number of years ago series of
experiments undertaken at universities to
show the effect combustion of the fuel using the
intermediate and low gears It found by anayzn0 the
combustion resulted at the higher engine speeds The
dtlons at low engine speeds particularly at wide
open throttle More unburned fuel found the
with engine running at wide throttle or in hoh
ing steep hill on high gear than at any other time
When the engine is driving through the lower gear il
running at higher speed the veloces through the intake
passages high, the fuel is mechanically vaporized to
charge and consequently the charge not rareed and
greater output for less amount Of fuel most likely to
result To all Of this in few words there is wide
effective steep hill climbing, example or ON
very heavy roads such sand where the car is actually
curing better fuel second onN high
Inc driver who changes allowing his engine to have
the advantage OF the leverage provided by the reduction
will avoid this excessive wear while is at the same Tins
saving fuel and adding to the life of the car IF the n0e
not used BRAKE the average set of brakes would
not STAND up for appreciabe length time There
only one point which be mentioned that is the ne
cessty for deciding before the hill entered Wbon ~
into second and if the hill very steep into low raar
before he starts descending the hill takes verv eTne
and practced driven to shift from high to second or from
second to first speed while descending hill