SUV

A second-generation (1995-2001) Ford Explorer, the best-selling midsize SUV in the United States

A sport utility vehicle, or SUV, is a type of passenger vehicle which combines passenger-carrying and load-hauling abilities with the versatility of a pickup truck. Most SUVs are designed with a roughly square cross-section, an engine comportment, a passenger and cargo compartment, and no dedicated hood. Most midsize and large SUVs have 5 or more seats, and a cargo area directly behind the last row of seats. Small SUVs, such as the Jeep Wrangler, typically have less 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 have developed to have the general shape of a station wagon. SUVs are typically taller, though, with a roughly square cross-section.

SUVs typically have higher seating than a station wagon and can be equipped with (four-wheel drive), providing an advantage in low traction environments. The design also allows for a large engine compartment, and many SUVs have large V-6 or V-8 engines. In countries where fuel is more expensive, buyers often opt for diesel engines, which have better fuel efficiency, and given that diesel fuel itself is often much cheaper than gasoline.

Popularity

SUVs became popular in US and Australia, especially so 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 large 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 preferred vehicle choice of women.

The most common reason for SUV popularity cited by owners was their safety advantage in a collision with regular cars. Some of their success is also due to their image, a substantial factor for many buyers. In the late 1990s and early 2000s, vehicle manufacturers sold the image of SUVs very effectively, with per-vehicle profits substantially higher than other automobiles. Historically, their simple designs and often outdated technology (by passenger car standards) often made the vehicles cheaper to make than comparably-priced cars. Still, SUVs are more expensive than sedans of similar quality and features.

In the mid 2000s, however, their popularity has waned, due to higher gasoline prices after a period of low prices when SUVs became popular. Current model SUVs take into account that 98% of SUV owners never offroad. As such, SUVs now have lower ground clearance and suspension designed primarily for paved road usage.

History

File:Mosk410h.jpg

Moskvitch 410.

Descended from commercial and military vehicles such as the Jeep and Land Rover, SUVs have been popular for many years with rural buyers due to their off-road abilities. In the last 25 years, and even more in the last decade, they have become popular with urban buyers. Consequently, more modern SUVs often come with more luxury features and some crossover SUVs, such as the BMW X5, the Acura MDX, and the Toyota RAV4, have adopted lower ride heights and car chassis to better accomodate their use for on-road driving.

Hybrid technology

The 2005 Ford Escape Hybrid is the first hybrid SUV, with a hybrid version of the Lexus RX 330 (known as the RX 400h) also available. Shortly after the Escape Hybrid's introduction, Mercury introduced a hybrid version of its Mariner, which is a lightly restyled Ford Escape. A hybrid version of the Toyota Highlander is available, and hybrids of the Mazda Tribute and Saturn VUE are in the pipeline. While some manufacturers (most notably Toyota in the Lexus RX 400h) are using added power generated from the hybrid systems primarily to give vehicles added performance, these hybrid SUVs still offer equal or better fuel efficiency than their conventionally-powered counterparts.

SUVs in remote areas

SUVs are often used in places as the Australian Outback, Africa, the Middle East, 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 developed for the US Armed Forces.

SUVs in recreation and motorsport

File:Rangeroversport.JPG

Range Rover Sport

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.

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.

Criticism

The explosive growth in SUV ownership has attracted a large amount of criticism, mainly of the risks to other road users and the environment, but also on the basis that the perceived benefits to the vehicle owner are illusory or exaggerated.

Tax benefits

In the United States, the so-called 'SUV subsidy' (Section 179 depreciation deduction) allows small-business owners to deduct up to $25,000 of the cost of a vehicle with a Gross vehicle weight rating of over 6000 lb (2722 kg) from their income tax calculation. Small-business owners may deduct $10,610 of the cost of a passenger automobile. This provides a slight tax incentive for businesses to purchase an SUV. However, the cost of both SUVs and automobiles is fully deductible over future years using normal depreciation. In previous years, this deduction reached $120,000 and was the subject of much criticism.

Safety

A Ford Excursion SUV next to a Toyota Camry

Safety is a common point of criticism. The majority of modern automobiles are constructed by a method called unibody or monocoque construction, whereby a steel body shell absorbs the impacts of collisions in crumple zones. Many SUVs, on the other hand, are constructed in the traditional manner of light trucks: body-on-frame, which, when negligently designed can provide a comparatively lower level of safety. However, some SUVs have designs based on unibody construction: the Ford Escape/Mazda Tribute, Lexus RX 330 and RX 400h, Hyundai Santa Fe, and Acura MDX are some examples. In fact, the Jeep Cherokee/Liberty (1984 on) and Grand Cherokee (1993 on) have used unibody construction from the start, and have hardly sacrificed ruggedness or offroad prowess in the process.

Risk to other drivers

Because of SUVs' greater height and weight, and often usage of body-of-frame constructions, it is documented many SUVs hurt overall public road safety by slightly reducing risk for people inside the SUV, but substantially increasing risk for those outside the SUV (in other vehicles or on foot). This is due to the SUVs' weight and height advantage in multi-vehicle accidents (resulting in much less deaths in the vehicle, but increasing risks for others) being counter-balanced by their raised center of gravity, which increases potential for rollover.

The considerable weight of larger SUVs (such as the Chevrolet Suburban and the Ford Excursion) makes collisions with other, smaller cars much less dangerous for the SUV and much more dangerous for the car. The higher ride and other design characteristics of many SUVs may also lead to greater damage to smaller crash partner cars. These mass and design dangers are known as crash incompatibility issues in the crash testing industry, and are a topic of active research. The most notable statistic in SUV design crash incompatibility is an increase in fatalities when an SUV strikes the head of a passenger or driver in a side-impact collision. This is one of the motivations for the development of side-curtain airbags in standard autos.

The high center of gravity of SUVs makes them more prone to rollover accidents (especially if the vehicle leaves the road or in emergency manoeuvres) than lower vehicles. In recent years, Consumer Reports has found a few unacceptable SUVs due to their rollover risk. This was also dramatically demonstrated in one Fifth Gear show using a Range Rover. Modern SUVs are usually designed to prevent rollovers on flat surfaces.

In 2004, the National Highway Traffic Safety Administration released figures showing that drivers of SUVs were 11 percent more likely to die in an accident than people in cars. [1] These figures may be confounded by variables other than the vehicles' inherent safety, for example the documented tendency for SUVs to be driven more recklessly (most sensationally perhaps, the 1996 finding that SUV drivers are more likely to drive drunk [2]). SUV drivers are also statistically less likely to wear their seatbelts. [3]

SUV safety concerns are compounded by a perception among some consumers that SUVs are safer for their drivers than standard autos; this perception is generally incorrect, although SUVs might provide more safety in a few situations. According to G. C. Rapaille, a psychological consultant to automakers (as cited in Gladwell, 2004), many consumers feel safer in SUVs simply because their ride height makes "[their passengers] higher and dominate and look down (sic). That you can look down [on other people] is psychologically a very powerful notion." This and the massive size and weight of SUVs may lead to consumers' false perception of safety (Gladwell, 2004). [4].

Similarly, a related perceived benefit for SUV drivers is that their higher seating enables them to have a better overview on the road, and may therefore be able to react sooner to crossing pedestrians or hazards ahead. However, this advantage is only relative to other vehicles: a higher vehicle, while affording a better view for its own driver, will tend to obscure the view for all other road users, thus decreasing general road safety, and sometimes frustrating other drivers.

In Europe, effective 2006, the fitting of bull bars, also known as grill guards to vehicles such as 4x4s and SUVs is illegal.

Risk to pedestrians

An SUV hitting a pedestrian is about twice as likely to kill as a car at equal speed. This is in part because the collision of an SUV with a pedestrian tends to impact the chest, while the collision of a car with a pedestrian tends to impact the knees.

Also the size and design of SUVs leads to a restricted driver's view of the area immediately surrounding the vehicle. The back view is particularly restricted. Young children and cars behind the SUV may be completely invisible. While it's a non-issue on the road, this makes backing out of a stall or a driveway more difficult and dangerous. Quite a few manufacturers try to remedy the problem by offering rear-view cameras or simple sensors that sound the alarm if the car is about to hit something. This is still rather new technology and is not fool-proof. Unfortunately, those tend to be pricey options and only a fraction of SUVs have them installed. Aftermarket offerings also exist for interested buyers.

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 (11.4 and 8.6 L/100 km, respectively).

As there is little incentive to change the design, SUVs have numerous fuel-inefficient features. The high profile of SUVs increases wind resistance. The heavy suspension and large engines increases vehicle weight. SUVs also often come with tires designed for off-road traction rather than low rolling resistance. The more car-like SUVs tend to have a somewhat lower profile and better road performance tires, but often still have several disadvantages, such as large, fuel-inefficient engines, more mass, and aerodynamics.

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, $m_{vehicle}$ for the vehicle mass, a for acceleration and v for the vehicle velocity.
• high crossectional area causing very high drag losses especially when driven at high speed ${F_{drag}=A_{cross}\cdot cw_{vehicle}\cdot {\frac {v_{air}^{2}\rho _{air}}{2}}}$ where F stands for the force, ${A_{cross}}$ for the crossectional area of the vehicle, ${\rho _{air}}$ for the density of the air and ${v_{air}}$ 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 ${F_{roll}=\mu _{roll}\cdot m_{vehicle}}$ where ${\mu _{roll}}$ stands for the rolling resistance factor and ${m_{vehicle}}$ for the vehicle mass.

Diesel-engined versions tend to show better fuel economy figures than gasoline-burning versions - checking a few offical figures shows that a small diesel 4x4 has better touring economy than the supercharged Mini Cooper S or many large saloon cars. Note though that gasoline contains about 15% less energy than diesel fuel per unit of volume, so direct comparison of fuel economy numbers can be misleading. Also, bear in mind that diesel is a more polluting fuel than gasoline, so a direct comparison of gallons/liters per mile/kilometer can be misleading.

Although SUVs have the image of being fuel hogs, compared to sport editions of standard cars, luxury cars and mini vans the SUV's don't come out so bad. Luxury cars and mini vans can have the same or even more weight than a SUV. Standard cars with a diesel engine can weigh more than a regular SUV. Sport editions of cars and tuned cars can have really bad fuel economics. Luxury cars and limousines often have larger engines than SUV's. The smallest consumer gasoline cars average from 1 liter per 16 km up to 1 liter per 20 km (40-50 mpg). Average gasoline cars average from 1 L/8 km up to 1 L/15 km (20-35 mpg). Most gasoline luxury cars, limousines, SUV's, sport editions and tuned cars vary from 1 L/6 km to 1 L/12 km (15-30 mpg).

Weight

The high gross vehicle weight rating of some larger SUVs (including the Ford Excursion or Hummer H2) technically limits their use on certain roads. Rural bridges often have a 6000 lb (2700 kg) weight limit, and some large SUVs surpass this limit when loaded. These laws are rarely enforced for SUVs, however, since these vehicles are seen as passenger vehicles instead of commercial trucks. Other vehicles can weigh as much as an SUV: the Dodge Grand Caravan exceeds the 6000 lb mark by 650 lb (295 kg), and the Honda Odyssey, at 5952 lb (2700 kg), and Kia Sedona, at 5959 lb (2703 kg), are close. For comparison, a midsize sedan such as the Honda Accord weighs 4080 lb (1851 kg) fully loaded. These weights are all for vehicles fully loaded to GVWR, and most owners rarely reach full capacity. However sometimes, SUVs may look heavier than they actually are. For instance, a 1999 Jeep Cherokee has a curb (empty) weight of 3300 lb (1500  kg), while a smaller car like the Volkswagen Golf diesel has a curb weight of 3100 lb (1400 kg).

Handling and braking

Due to the SUV's usually high weight and high center of mass, SUVs generally perform poorly in emergency manoeuvres. For example, in braking, the high center of mass would direct an excessive loading shift to the front tires, leading to an inefficiency of traction during braking.

Image

Some criticism of SUVs is based purely on their image as expensive, upscale status symbols for the (relatively) wealthy; and their stereotypically yuppie owners/drivers as arrogant, rude, and wasteful show-offs.

Others criticize SUVs for environmental reasons, pointing out that low fuel efficiency and high emissions make SUVs far less environmentally friendly than smaller cars. Some have gone as far as to connect recent oil crisis woes with widespread use of these vehicles.

In addition, some have criticized SUVs – particularly luxury models – because they come with electronic devices such as nagivation systems; power seats with memory settings; in-seat heaters and massage-type seat lumbar control; in-vehicle DVD players with flatscreen monitors; and vehicle stability control. Many critics see these features as simply unnecessary for normal commuting. Other points of criticism include the gadgets may become troublesome (adding to repair bills), they add to the overall weight of the vehicle, the luxury features are simply toys for the rich and provide additional opportunities for the owner to flaunt himself/herself, and – in some instances – serve as distractions to drivers and causing an accident risk.

Protests

Anti-SUV vandalism

In April 2005, William Cottrell, a 24-year-old American postgraduate student at Caltech was sentenced to more than eight years in federal prison and $3.5 million in fines for firebombing or vandalizing 125 SUVs at dealerships and a few homes in 2003.[5] Two of his associates fled the country to avoid prosecution. [6]

Slang

In southern England, SUVs, excluding farm vehicles such as Land Rovers, are often referred to in derogatory terms as "Soft-Roaders" or "Chelsea tractors", coined by London Mayor, Ken Livingstone. In the UK they are occasionally known as jeeps or Land Rovers no matter what make they actually are, although the increasing prevalence of these vehicles in recent years has decreased this colloquial usage. In New Zealand they are occasionally called "Fendalton tractors" or "Remuera tractors" after the higher priced suburbs in Christchurch and Auckland respectively. In Australia, particularly Victoria, they are referred to as "Toorak Tractors". In The Netherlands they are often called "PC Hooft-tractoren" after Amsterdam's most exclusive shopping street. SUVs are also criticized in the Netherlands for similar reasons, and some environmentalists are pushing local governments to deny SUV users parking spaces.

Recent Improvements

Manufacturers have added car-level bumpers to reduce other vehicles sliding under the SUV in collisions—SUVs have therefore become somewhat safer for other road users in recent years.

See also

• Four wheel drive

• Car classification
• Compact SUV
• Crossover SUV
• Esuvee
• RV
• Station wagon

References

• Gladwell, M. (2004, January 12). Big and bad. The New Yorker, LXXIX, 28-30. [7]
• Motor Trend. (Complete information on the Motor Trend reference is unavailable. However, the article was Motor Trend's announcement of the Lexus RX 300 as the 1999 SUV of the Year.)

Additional reading

• High and Mighty: SUVs--The World's Most Dangerous Vehicles and How They Got That Way Keith Bradsher. Published by PublicAffairs. ISBN 1586482033
• "Tragic Indifference : One Man's Battle with the Auto Industry over the Dangers of SUVs" Adam Penenberg. Published by HarperBusiness. ISBN 0060090588

External links

• SUVs actually illegal on many residential roads
• SUVs and oil dependency
• The psychology of SUV purchasing. Includes a comparison of vehicles and their 'deaths inside vehicle' and 'deaths caused/outside of vehicle' rates.
• Information on hybrid SUV's