Units of measurement

Click para leer versión en español.

Often we have to see in articles from car magazines, video games, even in real cars, some kinds of measurement units that are different from the ones we are used to see. This could create some misunderstandings for example in top speed runs, where in some places the measurement unit is the mile per hour, but in others places, could be kilometers per hour. This is because the world used to have a few measurement systems, depending of the region, but actually nowadays, is intended to use just one system for all the regions in the world.

Non-Metric User

In red color, the nations that have not currently adopted the SI (international system of units) as their primary or sole system of measurement.

In racing video games is very common to find this kind of confusion. Some games come with a default system which can’t be changed,others games give you the option to change between systems(imperial or metric), and others allows you to choose the measurement unit of your wish in every aspect (if you want Mph or km/h for the speed, between kilograms (kg) or pounds (lb) for the (mass) weights, etc ). This kind of option should be at all the racing games over the world because allows the user to choose freely its favorite measurement unit.

If you are interested to know how to convert from a system to the other, you are in the right place, here you will find how to convert the most popular measurement units used in the automotive world (specially in racing games).

Measuring Speed

Check here the Mph, the Km/h, and some variants as “m/s” which are used in some racing games.

Ford Mondeo MK3 ST220 - Speedometer

Speedometer, with mph (black) and km/h (red) units

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Speedometer

Tachometer (left) and Speedometer in Mph (right)


The MPH is coming from the imperial system, and is used in the United States and the United Kingdom. MPH is often used in sporting events such as baseball or tennis, to express the speed of delivery of a ball.

The MPH is used to express the number of statute miles covered in one hour, should not be confused with the nautical mile and such variants.

1 MPH is equal to 1.60934 km/h.
This means, if you are in a car at 100 MPH, actually you are driving at 160 km/h.

If you want to know how much MPH are in “x” km/h, you should divide the amount of km/h between 1.609344, or multiply it by 0.62137, is the same.

Example: “400 km/h”
400/1.60934 ≈ 248.54 -> 248.54 MPH
400X 0.62137 ≈248.54 -> 248.54 MPH

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Speedometer (kmh)

speedometer using km/h only.

The km/h is coming from the metric system, and is used worldwide, except some countries
as the United States and the United Kingdom.
1km/h = 0.62137 MPH.

If you are going at the speed of 300km/h, this means that you are driving around 186.mph, this is the
equivalent speed.

If you want to know how much km/h are in “x” mph, you should multiply the amount of mph by
1.609344, or divide it by 0.62137
, is the same.

For example: “300 MPH”
300×1.609 ≈ 482.8 -> 482.8 km/h.
see also:
300/0.62137≈ 482.8 ->482.8 km/h

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Sometimes, you could find the speed expressed in “m/s“.

is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds.

If you want to know how much km/h is just 1 m/s, or how much m/s is 1 km/h, check this:

1 m/s = 3.6 km/h
1 km/h ≈ 0.277 m/s

so, with this you can figure it out how to convert between units.

Example: Convert 50 km/h to “m/s”:
1 km/h ≈ 0.277 m/s, then:
50 x 0.277 ≈ 13.88 m/s
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Example #2: Convert 100 m/s to km/h:
1 m/s = 3.6 km/h, then:
100 x 3.6 =360 km/h

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Measuring the weight or mass

The weight or mass of a car, generally could be expressed in two main units; the kilogram “kg” or the pound “lb”. You may find the weight expressed in “ton”/”metric tonne”, but don´t worry, here you will see how to convert between each unit.

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The kilogram or kilogramme (SI symbol: kg), also known as the kilo, is the base unit of mass in the International System of Units and is defined as being equal to the mass of the International Prototype Kilogram (IPK), which is almost exactly equal to the mass of one liter of water. The avoirdupois (or international) pound, used in both the Imperial system and U.S. customary units, is defined as exactly 0.45359237 kg, making one kilogram approximately equal to 2.2046 avoirdupois pounds.

After reading that, we have that 1 kg ≈ 2.2046 lb, so; to convert from kg to lb we just have to multiply the amount of kg by “2.2046”.

Example;

A car that weights 1000 kg (this is lightweight for actual production standards), just multiply “1000” by 2.2046;
1000×2.2046 ≈ 2204.6 => 2204.6 lb.

You can do the same dividing the amount of kg by 0.45359, which will bring you a very close result: 1000/0.45359 ≈ 2204.6 => 2204.6 lb

But, from where is coming the “0.45359”?
This is because: 1 lb ≈ 0.45359 kg.

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The pound or pound-mass (abbreviations: lb, lbm, lbm, [1] ) is a unit of mass used in the imperial, United States customary and other systems of measurement. A number of different definitions have been used, the most common today being the international avoirdupois pound which is legally defined as exactly 0.45359237kilograms.

With this, we have that:
1 lb ≈ 0.4535 kg.
1 kg ≈ 2.2046 lb

If you already know the amount of lb of something, and you want to convert it to kg, simply do the next:
Multiply the amount of lb by 0.4535
or
divide the amount of lb by 2.2046

Example:

1450 lb to kg:
1450 x 0.4535 657 kg.
or
1450 / 2.2046 657 kg.

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The tonne (SI unit symbol: t) is a metric system unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI.[1][2] To avoid confusion with the ton, it is also known as the metric tonne and metric ton in the United States[3] and occasionally in the United Kingdom.[4] In SI units and prefixes, the tonne is a megagram (Mg), a rarely-used symbol, easily confused with mg, for milligram.[5]

In the U.S., the National Institute of Standards and Technology supports the symbol “t” for the tonne.[6] The abbreviation “mt” or “MT” is also used in the U.S.[7]

1 tonne = 1000 kg.

The SI unit symbol for the tonne is “t”. Abbreviations for “tonne” (“metric ton” and “metric tonne”) include “T”, “mT”, “MT”, and “mt” (especially in the combination “mmt” or “MMT” for “million metric tons”), and “Te” (particularly in the offshore and nuclear industries).[citation needed] SI has no abbreviations for SI units, only symbols, and some of the abbreviations in use are actually SI symbols for other units: “T” is the SI symbol for the tesla and “Mt” is the SI symbol for megatonne.

To convert from metric ton, to kg, you have to multiply the amount of metric tons by 1000.
Example:
2 t= 2×1000 = 2000 kg.

Besides you can convert this to lb, if you want to convert metric tons, to lb directly, keep in mind that 1000 kg = 2204.623 lb. All you need is multiply the amount of metric tonnes by 2204.623:
2 t = 2×2204.623 4409.245 lb

To convert from kg to metric tonnes, divide the amount of kg by 1000:
Example:
3450 kg = 3450/1000 = 3.45 t

to convert from lb to metric tonnes, divide the amount of lb by 2204.623:
Example:

7606 lb = 7606/2204.623 3.4500 t

Measuring the torque & power

Dyno
You could find so many units to measure the power (and torque), because of this, this has to be brief. Starting with the Power:

Horsepower (hp) is the name of several units of measurement of power. The most common definitions equal between 735.5 and 750 watts.[1] Horsepower was originally defined to compare the output of steam engines with the power of draft horses in continuous operation. The unit was widely adopted to measure the output of piston engines, turbines, electric motors, and other machinery. The definition of the unit varied between geographical regions. Most countries now use the SI unit watt for measurement of power. With the implementation of the EU Directive 80/181/EEC on January 1, 2010, the use of horsepower in the EU is only permitted as supplementary unit.

1 hp ≈ 0.74569 kW ≈ 1.0138 ps

The kilowatt is equal to one thousand (103) watts. This unit is typically used to express the output power of engines and the power consumption of electric motors, tools, machines, and heaters. It is also a common unit used to express the electromagnetic power output of broadcast radio and television transmitters.

One kilowatt of power is approximately equal to 1.34 horsepower. A small electric heater with one heating element can use 1.0 kilowatt, which is equivalent to the power consumption of a household in the United States averaged over the entire year (8900 kW h divided by 365×24 hours).[5] (UK household consume about half this amount)[6] Also, kilowatts of light power can be measured in the output pulses of some lasers.

1 kW ≈ 1.341 hp ≈ 1.3596 ps

This unit (German: Pferdestärke = horse strength) is no longer a statutory unit, but is still commonly used in Europe, South America, Japan and India especially by the automotive and motorcycle industry. It was adopted throughout continental Europe with designations equivalent to the English horsepower, but mathematically different from the British unit.

DIN 66036 defines one horsepower as the power to raise a mass of 75 kilograms against the earth’s gravitational force over a distance of one metre in one second;[11] this is equivalent to 735.49875 W. Similar definitions were already common to the time of James Watt.

The PS was adopted by the Deutsches Institut für Normung (DIN) and then by the automotive industry throughout most of Europe, under varying names. In 1992, the PS was rendered obsolete by EEC directives, when it was replaced by the kilowatt as the official power measuring unit. It is still in use for commercial and advertising purposes, in addition to the kW rating, as many customers are still not familiar with the use of kilowatts for engines.

***For further reading about Wheel HorsePower or bhp, please click below:
whp, bhp, shp, ihp, nhp.***

1 ps ≈ 0.9863hp ≈ 0.73549 kW

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Summary:

1 hp 0.74569 kW 1.0138 ps -> to convert from HorsePower (hp) to kilowatts (kW) or PS you have to multiply the amount of hp by the conversion factor.

Example:

Converting 320 hp to kW -> 320 x 0.73569 238 kW

Converting 320 hp to ps -> 320 x 1.0138 324 ps

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1 kW 1.341 hp 1.3596 ps -> to convert from kilowatt (kW) to horsepower (hp) or PS, you have to multiply the amount of kW by the conversion factor.

Example:

Converting 320 kW to hp -> 320 x 1.341 429 hp

Converting 320 kW to ps -> 320 x 1.3596 435 ps

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1 ps 0.9863 hp 0.73549 kW -> to convert from ps to horsepower (hp) or kilowatt (kW), you have to multiply the amount of kW by the conversion factor.

Example

Converting 320 ps to hp -> 320 x 0.9863 ≈ 315 hp

Converting 320 ps to kW -> 320 x 0.73549 kw 235 kw

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Measuring the torque:

Boxsterdyno

Torque, moment or moment of force (see the terminology below), is the tendency of a force to rotate an object about an axis,[1]fulcrum, or pivot. Just as a force is a push or a pull, a torque can be thought of as a twist to an object. Mathematically, torque is defined as the product of force and the lever-arm distance, which tends to produce rotation.

Loosely speaking, torque is a measure of the turning force on an object such as a bolt or a flywheel. For example, pushing or pulling the handle of a wrench connected to a nut or bolt produces a torque (turning force) that loosens or tightens the nut or bolt.

Usual units in the automotive world:

A newton metre is a unit of torque (also called “moment“) in the SI system. The symbolic form is Nm or N·m,[1] and sometimes hyphenated newton-metre. One newton metre is equal to the torque resulting from a force of one newton applied perpendicularly to a moment arm which is one metre long.

Conversion factors

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A pound-foot (lb·ft or lbf·ft) is a unit of torque (a vector). One pound-foot is the torque created by one pound force acting at a perpendicular distance of one foot from a pivot point.

One pound-foot is exactly 1.3558179483314004 newton meters.[note 1]

The name “pound-foot”, intended to minimize confusion with the foot-pound as a unit of work, was apparently first proposed by British physicist Arthur Mason Worthington.[1] However, foot-pound (ft·lb or ft·lbf) is also sometimes used interchangeably with “pound-foot” to express torque.[2]

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The kilogram-force (kgf or kgF), or kilopond (kp, from Latin pondus meaning weight), is a gravitational metric unit of force. It is equal to the magnitude of the force exerted by one kilogram of mass in a 9.80665 m/s2 gravitational field (standard gravity, a conventional value approximating the average magnitude of gravity on Earth).[1] Therefore one kilogram-force is by definition equal to 9.80665 N.[2][3] Similarly, a gram-force is 9.80665 mN, and a milligram-force is 9.80665 µN.

One kilogram-force is approximately 2.204622 pounds.

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Summary:

1 Nm ≈ 0.7375 lb-ft ≈ 0.1019 Kgm

Example:
Converting 1250 Nm to lb-ft: 1250 x 0.7375 ≈ 921 lb-ft.

Converting 1250 Nm to Kgm: 1250 x 0.1019 ≈ 127 Kgm.

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1 lb-ft ≈ 1.355 Nm ≈ 0.1382 Kgm

Example:

Converting 1250 lb-ft to Nm: 1250 x 1.355 ≈ 1693 Nm.

Converting 1250 lb-ft to Kgm: 1250 x 0.1382 172 Kgm.

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1 Kgm ≈ 9.806 Nm ≈ 7.233 lb-ft

Example:

Converting 1250 Kgm to Nm: 1250 x 9.806 12257 Nm.

Converting 1250 Kgm to lb-ft: 1250 x 7.233 9041 lb-ft.

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If you want, you can use an online calculator:

http://www.numberfactory.com

main page:

power

Torque
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http://www.boosttown.com

Main page

Power & Torque:

**Both websites have different available options to convert, check them out.**

All what you need is to know the conversion factor. Basically, you have to multiply or divide, depending of the case and you will get your desired unit.

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Posted on June 30, 2012, in General, Uncategorized and tagged , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , . Bookmark the permalink. 2 Comments.

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