SUV

A sport utility vehicle, or SUV, is a type of passenger vehicle which combines the

load-hauling and versatility of a pickup truck with the passenger-carrying space of a van or

station wagon. Most SUVs are designed with a roughly square cross-section, an engine

compartment, a combined passenger and cargo compartment, and no dedicated trunk. Most

mid-size and full-size SUVs have 5 or more seats, and a cargo area directly behind the last

row of seats. Mini SUVs, such as the Jeep Wrangler, may have fewer seats.

It is known in some countries as an off-roader or four wheel drive, often abbreviated to 4WD

or 4x4, and pronounced "four-by-four". More recently, SUVs designed primarily for driving on

roads have grown in popularity. A new category, the crossover SUV uses car components for

lighter weight and better fuel economy.


Design characteristics

SUVs were traditionally derived from light truck platforms, but several SUVs and crossover

SUVs are based on platforms of unibody construction.[1].

SUVs typically have high seating and most can be equipped with four wheel drive, providing

an advantage in low traction environments. The design also allows for a large engine

compartment, which allows for a wide variety of engine choices, both gasoline and diesel.


Popularity

SUVs became popular in the United States, Canada, and Australia in the 1990s and early 2000s

for a variety of reasons. Buyers became drawn to their large cabins, higher ride height, and

perceived safety when in the market for a new vehicle. Additionally, most full-size SUVs

have far greater towing capacities than conventional cars, allowing owners to tow RVs,

trailers, and boats with relative ease, adding to the utilitarian image.

A large growth in SUV popularity and sales is due to advertisement targeted towards women.

Women constitute more than half of SUV drivers, and SUVs are the most popular vehicle choice

of women in the United States. [citation needed]

In Australia, a unique situation resulted in the growth in popularity of SUVs. There, SUVs

have a much lower import duty compared with cars. This means a typical SUV has a significant

price advantage over a similarly-equipped, imported sedan. However, in recent years, the

import duty has been lowered for cars as well, and is currently at 10% (compared with 5% for

SUVs).

A common reason for SUV popularity cited by owners was their perceived safety advantage in a

collision with regular cars. For instance, the higher profile allows for better visability

and anticipation of danger. The enhanced weight helped reduce the risk of injury by a third

in children under the age of 16, though the roll-over fatality risk is much higher in SUVs

than cars negating the advantage.[citation needed] Some of their success could also be

attributed to their "utilitarian" image. In the late 1990s and early 2000s, vehicle

manufacturers sold SUVs very effectively, with per-vehicle profits substantially higher than

other automobiles. Historically, their simpler designs often made the vehicles cheaper to

make than comparably-priced cars.

In the mid 2000s, however, their popularity has waned, due to higher gasoline

prices[citation needed], rollover accident fatalities[citation needed] and higher relative

pollution.[citation needed] As of the spring of 2006, some of the larger SUVs now require

over 100USD per fillup, making thier everyday use more cost-prohibitive.[citation needed]

Current model SUVs (crossovers) take into account that 98% of SUV owners never

offroad[citation needed]. As such, SUVs now have lower ground clearance and suspension

designed primarily for paved road usage.
[edit]

SUVs in remote areas

SUVs are often used in places such as the Australian Outback, Africa, the Middle East,

Alaska, Northern Canada and most of Asia, which have limited paved roads and require the

vehicle to have all-terrain handling, increased range, and storage capacity. The low

availablity of spare parts and the need to carry out repairs quickly allow model vehicles

with the bare minimum of electric and hydraulic systems to predominate. Typical examples are

the Land Rover, the Toyota Land Cruiser and the Lada Niva.

SUVs targeted for use in civilization have traditionally originated from their more rugged

all-terrain counterparts. For example the Hummer H1 is derived from the HMMWV, originally

developed for the US Armed Forces.
[edit]

Other names

Outside of North America and India, these vehicles are known simply as four-wheel-drives,

often abbreviated to "4WD" or "4x4". They are classified as cars in countries such as the UK

where the U.S. distinction between cars and 'light trucks' is not used. In Australia, the

automotive industry and press have recently adopted the term SUV in place of four wheel

drive in the description of vehicles and market segments. "Utility" or "ute" refers to an

automobile with a flatbed rear or pick-up, typically seating two passengers and is often

used by tradesmen, and is typically not a 4WD vehicle.
[edit]

SUVs in recreation and motorsport

SUVs are also used to explore off-road places otherwise unreachable by vehicle or for the

sheer enjoyment of the driving. In Australia, China, Europe, South Africa and the U.S. at

least, many 4WD clubs have been formed for this purpose. Modified SUVs also take part in

races, most famously in the Paris-Dakar Rally, and the Australian Safari.

With the increasing urbanisation of the world, SUVs are also becoming more of a requirement

for those seeking unmodified landscapes and isolation, especially in nations with large

wilderness areas through which a viable road network could not be maintained without

excessive costs. Of course, roads are rarely constructed with scenic purposes foremost in

mind, instead trying to utilise the shortest and most economical length in order to reach a

specific destination and in many cases this means many natural features of interest are

inaccessible to cars. To travel with the absence of this infrastructure (which often leads

to settlements being built) serves to add to the appeal of SUV ownership due to a sense of

independence this invokes in many people, an ability to appreciate natural landscapes upon

their own terms.

The recreation value of SUVs also brings with it a pro environmentalist agenda which is

often overlooked in debates over their overall merits. By allowing owners to go off road,

SUVs promote a greater value being applied to wilderness areas, an attachment difficult to

gain through reading or simply seeing things on television. SUV clubs often promote this

ideal and a commercial manifestation of this can be seen in the number of tourism operators

dependent on SUVs for their activities, Australia being a strong example. Sensible off road

driving can promote a greater physical connection between people and the pristine

environment, something which has decreased with ever growing urban areas


Fuel economy

The recent popularity of SUVs is one reason the U.S. population consumes more gasoline than

in previous years. SUVs are as a class much less fuel efficient than comparable passenger

vehicles. The main reason is that SUVs are classified by the U.S. government as light

trucks, and thus are subject to the less strict light truck standard under the Corporate

Average Fuel Economy (CAFE) regulations. The CAFE requirement for light trucks is an average

of 20.7 mpg (US), versus 27.5 mpg (US) for passenger cars (8.6 and 11.4 km/L, respectively).

As there is little incentive to change the design, SUVs have numerous fuel-inefficient

features. The high profile of SUVs increases wind resistance. Heavier suspensions and larger

engines increase vehicle weight. Some SUVs also often come with tires designed for off-road

traction rather than low rolling resistance.

The low fuel economy is caused by

* high parasitic masses (compared to the average load) causing high energy demand in

transitional operation (in the cities) {P_{accel}= m_{vehicle} \cdot a \cdot v } where P

stands for power, mvehicle for the vehicle mass, a for acceleration and v for the vehicle

velocity.
* high cross-sectional area causing very high drag losses especially when driven at high

speed {P_{drag}= A_{cross} \cdot cw_{vehicle} \cdot \frac {v_{air}^3 \rho_{air}} {2} } where

P stands for the power, Across for the cross-sectional area of the vehicle, ρair for the

density of the air and vair for the relative velocity of the air (incl. wind)
* high rolling resistance due to all-terrain tires (even worse if low pressure is needed

offroad) and high vehicle mass driving the rolling resistance {P_{roll}= \mu_{roll} \cdot

m_{vehicle} \cdot v } where μroll stands for the rolling resistance factor and mvehicle for

the vehicle mass.

Average data for vehicle types sold in the U.S.A. (source theautochannel.com):