An automobile or motor car is a
wheeledmotor
vehicle for
transportingpassengers,
which also carries its own
engine or motor. Most definitions of the term specify that automobiles are
designed to run primarily on roads, to have seating for one to eight people, to
typically have four wheels, and to be constructed principally for the
transport
of people rather than goods.[1]
However, the term "automobile" is far from precise, because there are many types
of vehicles that do similar tasks.
Automobile comes via the
French language, from the
Greek language by combining auto [self] with mobilis [moving];
meaning a vehicle
that moves itself, rather than being pulled or pushed by a separate animal or
another vehicle. The alternative name car is believed to originate from
the Latin word
carrus or carrum [wheeled vehicle], or the
Middle English word carre [cart]
(from
Old North French), and karros; a
Gallicwagon.[2][3]
As of 2002, there were 590 million passenger cars worldwide (roughly one car
per eleven people).[4]
Although
Nicolas-Joseph Cugnot is often credited with building the first
self-propelled mechanical vehicle or automobile in about 1769 by adapting an
existing horse-drawn vehicle, this claim is disputed by some, who doubt Cugnot's
three-wheeler ever ran or was stable. Others claim
Ferdinand Verbiest, a member of a
Jesuit mission in China, built the first steam-powered vehicle around 1672
which was of small scale and designed as a toy for the Chinese Emperor that was
unable to carry a driver or a passenger, but quite possibly, was the first
working steam-powered vehicle ('auto-mobile').[5][6]
What is not in doubt is that
Richard Trevithick built and demonstrated his Puffing Devil road
locomotive in 1801, believed by many to be the first demonstration of a
steam-powered road vehicle although it was unable to maintain sufficient steam
pressure for long periods, and would have been of little practical use.
François Isaac de Rivaz, a Swiss inventor, designed the first
internal combustion engine, in 1806, which was fueled by a mixture of
hydrogen
and oxygen and
used it to develop the world's first vehicle, albeit rudimentary, to be powered
by such an engine. The design was not very successful, as was the case with
others such as
Samuel Brown,
Samuel
Morey, and
Etienne Lenoir with his
hippomobile, who each produced vehicles (usually adapted carriages or carts)
powered by clumsy internal combustion engines.[8]
In November 1881 French inventor
Gustave Trouvé demonstrated a working three-wheeled automobile that was
powered by electricity. This was at the International Exhibition of Electricity
in Paris.[9]
An automobile powered by his own
four-stroke cycle gasoline engine was built in
Mannheim,
Germany by
Karl Benz in 1885 and granted a
patent in
January of the following year under the auspices of his major company,
Benz & Cie., which was founded in 1883. It was an
integral design, without the adaptation of other existing components and
including several new technological elements to create a new concept. This is
what made it worthy of a patent. He began to sell his production vehicles in
1888.
Community Action for Sustainable Transport - Draft 18.11.2008
This policy uses some strategies first developed by Motorcycling
Australia.
Background
For trips where public transport, walking and cycling are not good
options people should consider using a two-wheeled motor vehicle (TWMV)
rather than a car.
Switching from a car to a motorcycle, scooter or electric bike is an
easy way for people to reduce congestion, greenhouse emissions and save
money on fuel.
TWMVs make more efficient use of fuel, road space and parking space than
a single occupant car and can play a part in the campaign to reduce
congestion and climate change.
When driven below the speed limit TWMVs also pose less of a safety risk
to other road users than cars, trucks and buses due to their weight.
TWMVs are a more affordable transport option than driving a single
occupant car, and will also help preserve oil reserves for essential
agricultural, medical and transport uses.
All levels of Government should be doing more to encourage people to
switch from their car to TWMVs.
Proposed strategies
More free parking spaces for TWMVs at activity centres and public
transport nodes. Parking must be safe, conveniently located and ensure
pedestrian, wheelchair and cyclist access is not obstructed. Car parks
should be reclaimed for TWMV parking where possible.
Inclusion of two-wheeled motor vehicles in National Road Transport
policies
Reduction in registration fees for TWMVs
Provision of TWMV-only lanes on key arterial roads
Exemption from tolls on tolled roads and infrastructure for TWMVs
Mandatory TWMV parking to be included in the construction plans for new
buildings
Integration of TWMVs into the planning for Public Transport projects,
such as park and ride for bikes.
A national standard that restricts the speed of new TWMVs available for
the general public to 120km/hr
Advertising campaigns to encourage people to switch from a car to a
two-wheeled motor vehicle
Government purchase of electric bicycles for use by employees and
citizens
Fuel efficiency, in its basic sense, is the same as
thermal efficiency, meaning the efficiency of a process that
converts chemical potential energy contained in a carrier
fuel into
kinetic energy or
work. Overall fuel efficiency may vary per device, which in turn may
vary per application, and this spectrum of variance is often illustrated
as a continuous
energy profile. Non-transportation applications, such as
industry, benefit from increased fuel efficiency, especially
fossil fuel power plants or industries dealing with combustion, such
as
ammonia production during the
Haber process. The United States Department of Energy and the EPA
maintain a Web site with fuel economy information, including testing
results and frequently asked questions.
In the context of
transportation, "fuel efficiency" more commonly refers to the
energy efficiency of a particular vehicle model, where its
total output (range, or "mileage" [U.S.]) is given as a
ratio of
range units per a unit amount of input fuel (gasoline,
diesel, etc.). This ratio is given in common measures such as "liters
per 100
kilometers" (L/100 km) (common in Europe and Canada or "miles
per gallon"
(mpg)
(prevalent in the USA, UK, and often in Canada, using their respective
gallon measurements) or "kilometres per litre"(kmpl) (prevalent in Asian
countries such as India and Japan). Though the typical output measure is
vehicle range, for certain applications output can also be
measured in terms of weight per range units (freight)
or individual passenger-range (vehicle range / passenger capacity).
This ratio is based on a car's total properties, including its
engine
properties, its body
drag, weight, and
rolling resistance, and as such may vary substantially from the
profile of the engine alone. While the thermal efficiency of
petroleum
engines has improved in recent decades, this does not necessarily
translate into fuel economy of
cars, as people in
developed countries tend to buy bigger and heavier cars (i.e.
SUVs will get less range per unit fuel than an
economy car).
Hybrid vehicle designs use smaller combustion engines as electric
generators to produce greater range per unit fuel than directly powering
the wheels with an engine would, and (proportionally) less
fuel emissions (CO2
grams) than a conventional (combustion engine) vehicle of similar
size and capacity. Energy otherwise wasted in stopping is converted to
electricity and stored in batteries which are then used to drive the
small electric motors. Torque from these motors is very quickly supplied
complementing power from the combustion engine. Fixed cylinder sizes can
thus be designed more efficiently.
"Energy efficiency" is similar to fuel efficiency but the input is
usually in units of energy such as British thermal units (BTU),
megajoules (MJ), gigajoules (GJ), kilocalories (kcal), or kilowatt-hours
(kW·h). The inverse of "energy efficiency" is "energy intensity", or the
amount of input energy required for a unit of output such as
MJ/passenger-km (of passenger transport), BTU/ton-mile (of freight
transport, for long/short/metric tons), GJ/t (for steel production),
BTU/(kW·h) (for electricity generation), or litres/100 km (of vehicle
travel). This last term "litres per 100 km" is also a measure of "fuel
economy" where the input is measured by the amount of fuel and the
output is measured by the
distance travelled. For example:
Fuel economy in automobiles.
Given a heat value of a fuel, it would be trivial to convert from
fuel units (such as litres of gasoline) to energy units (such as MJ) and
conversely. But there are two problems with comparisons made using
energy units:
There are two different heat values for any hydrogen-containing
fuel which can differ by several percent (see below). Which one do
we use for converting fuel to energy?
When comparing transportation energy costs, it must be
remembered that a
kilowatt hour of electric energy may require an amount of fuel
with heating value of 2 or 3 kilowatt hours to produce it.
The specific energy content of a fuel is the heat energy obtained
when a certain quantity is burned (such as a gallon, litre, kilogram).
It is sometimes called the "heat of combustion". There exists two
different values of specific heat energy for the same batch of fuel. One
is the high (or gross) heat of combustion and the other is the low (or
net) heat of combustion. The high value is obtained when, after the
combustion, the water in the "exhaust" is in liquid form. For the low
value, the "exhaust" has all the water in vapor form (steam). Since
water vapor gives up heat energy when it changes from vapor to liquid,
the high value is larger since it includes the latent heat of
vaporization of water. The difference between the high and low values is
significant, about 8 or 9%.
In
thermodynamics, the thermal efficiency ()
is a
dimensionless performance measure of a thermal device such as an
internal combustion engine, a
boiler,
or a
furnace, for example. The input,
,
to the device is
heat, or
the heat-content of a fuel that is consumed. The desired output is
mechanical
work,
,
or heat,
,
or possibly both. Because the input heat normally has a real financial
cost, a memorable, generic definition of thermal efficiency is[1]
When expressed as a percentage, the thermal efficiency must be
between 0% and 100%. Due to inefficiencies such as friction, heat loss,
and other factors, thermal efficiencies are typically much less than
100%. For example, a typical gasoline automobile engine operates at
around 25% thermal efficiency, and a large coal-fueled electrical
generating plant peaks at about 46%.
The largest diesel engine in the world peaks at 51.7%. In a
combined cycle plant, thermal efficiencies are approaching 60%.[2]
The
second law of thermodynamics puts a fundamental limit on the thermal
efficiency of heat engines. Surprisingly[citation
needed], even an ideal, frictionless engine can't
convert anywhere near 100% of its input heat into work. The limiting
factors are the temperature at which the heat enters the engine,
,
and the temperature of the environment into which the engine exhausts
its waste heat,,
measured in the absolute
Kelvin
or
Rankine scale. From
Carnot's theorem, for any engine working between these two
temperatures:
This limiting value is called the Carnot cycle efficiency
because it is the efficiency of an unattainable, ideal, lossless (reversible)
engine cycle called the
Carnot cycle. No heat engine, regardless of its construction, can
exceed this efficiency.
Examples of
are the temperature of hot steam entering the turbine of a steam power
plant, or the temperature at which the fuel burns in an internal
combustion engine.
)
is a
dimensionless performance measure of a thermal device such as an
internal combustion engine, a
boiler,
or a
furnace, for example. The input,
,
to the device is
heat, or
the heat-content of a fuel that is consumed. The desired output is
mechanical
work,
,
or heat,
,
or possibly both. Because the input heat normally has a real financial
cost, a memorable, generic definition of thermal efficiency is[1]
,
and the temperature of the environment into which the engine exhausts
its waste heat,
,
measured in the absolute
Kelvin
or
Rankine scale. From
Carnot's theorem, for any engine working between these two
temperatures:
