Omaha daily bee. (Omaha [Neb.]) 187?-1922, 1910-08-28
MOTOR HORSE PJwER TEST
How Car Users Can Easily Determine
Power Of Car.
TAX IN PROPORTION TO POWER
Piston speed ~ Not an Element OF
the FormuIa---NearIy as Accurate
ms the More Complicated
Methods.

According TO the provisions OF the new
automobile law Of New York state. which
went into effect August 1. motorists must
pay annually tax according 20 the horse
power OF their cars. based on the horse
power formula adopted some years ago by
the Association Of Licensed Automobile
Manufacturers, and known as the A. L. A.
NJ. horsepower formula.
The annual taxes are as follows:
For cars of twenty-five horsepower or
less, IS.
For cars of more than twenty-five and
loss than thirty-five horsepower, $40.
For cars of thirty-five and less than
| fifty horsepower. SIS.
For cars Of fifty horsepower or more. s25.
There have been so many inquiries re-
Gently that Il Is thought well 10 explain
how the user OF an automobile driven by a
gasoline engine can tell easily the official
horsepower rating Of his car under the
New York law.
The Association Of Licensed Automobile
Manufacturers publishes in the annual hand
book Of Gasoline automobiles table from
which can be seen at a glance the rating
OF a car according to the official formula.
This table is also published In pamphlet
form, showing the ratings OF all motors OF
from one to six cylinders, having a bore
Of from two and one-half to elk inches Cor
sixty-four TO 1852 millimeterD.
Figure for Yourself.
Anybody can, however figure for himself
the rating Of his car without referring to
this table. Because the formula is very
simple being as follows. ID square times
N divided by two and one-halD, wherein d
represents the cylinder bore, N the number
Of cylinders ahd 2.B 4 constant based on the
average view of the engineers as to a fair
conservative rating for a four-cylinder
motor. at 1000 feet per minute piston speed,
All there is to do, after knowing the
cylinder bore is to square the same, multi
| ply by the number OF cylinders and divide
the result by two and one-hah
| The Association of Licensed Automobile
Manufacturers formula, therefore, con-
stitites a simple, fair, uniform rating basis
for automobile engines. within the limits
OF construction which have for some time
come to be recognized in the motor car
industry as commercially satisfactory. The
primary purpose of the formula was to give
light to the public as between motors rated
high, as Offering big value. and those rated
modestly, as showing superior performance
over nominally high-powered cars 1t is
now adequately realized that the Associa-
| uon OF Licensed Automobile Manufacturers
type of formula is OF by far the most simple
character that can be devised and that it
is, moreover, almost inappreciaby less ac-
curate than any Of the most complicated
formulate that have been advanced, so long
as It is applied to the ordinary standard
engines which are used for the propulsion
of pleasure vehicles.
Piston speed is not an element of the
Association OF Licensed Automobile Manu-
lecturers formula itself. But the formula
is based on 1000 feet per minute piston
speed; that is, in the case OF two motors
having the same number of cylinders and
the same cylinder bore. but different length
of stroke, It is assumed that the motor
with the shorter stroke will make q greater
number OF revolutions per minute relatively.
AS per example the application OF the
Association Of Licensed Automobile Manu-
facturers formula TO four-cylinder motor
with q five-inch bore would be as follows:
Square OF Eve inches equals twenty-five;
multiplied by four, the number of cylinders,
equals 100; divided by two and one-half.
gives forty horsepower.