accelerator pedal



This article is about the semi-truck. For the North American use of the word, see pickup truck.

A truck is a vehicle for carrying goods and materials. The word "truck" possibly derives from the Greek "trochos", meaning "wheel." In North America, the big wheels of wagons were called trucks. When the gasoline-engine driven trucks came into fashion, these were called "motor trucks." Lorry is a term from the United Kingdom and the Republic of Ireland, but is only used for the medium and heavy types (see below), i.e. a van, a pickup or a Jeep would never be regarded as a lorry. Other languages have loanwords based on these terms, such as the Malay language and the Spanish language in northern Mexico.

In Australia and New Zealand a small vehicle with an open back is called a ute (short for "utility vehicle") or a pick-up and the word "truck" is reserved for larger vehicles.

In the United States a commercial driver's license is required to drive any type of vehicle weighing 26,001 lbs or more.


The oldest truck was built in 1896 by Gottlieb Daimler. Small trucks such as SUVs or pickups, and even light medium-duty trucks in North America and Russia will use gasoline engines. Most heavier trucks use four stroke turbo intercooler diesel engines, although there are alternatives. Huge off-highway trucks use locomotive-type engines such as a V12 Detroit Diesel two stroke engine.

North American manufactured highway trucks almost always use an engine built by a third party, such as CAT, Cummins, or Detroit Diesel. The only exceptions to this are Volvo and its subsidiary Mack Trucks, which are available with their own engines. Freightliner, Sterling Trucks and Western Star, subsidiaries of Daimler AG, are available with Mercedes-Benz and Detroit Diesel engines. Trucks and buses built by Navistar International usually also contain International engines. The Swedish manufacturer Scania claims they stay away from the U.S. market because of this third party tradition.

In the European Union all truck engines must comply with Euro 5 regulations.


Small trucks use the same type of transmissions as almost all cars which have either an automatic transmission or a manual transmission with synchronisers. Bigger trucks often use manual transmissions without synchronisers which have less bulk and weight although synchromesh transmissions are used in larger trucks as well. Transmissions without synchronisers known as "crash boxes" require double clutching for each shift, (which can lead to repetitive motion injuries), or a technique known colloquially as "floating," a method of changing gears which doesn't use the clutch, except for starts and stops, due to the physical effort of double clutching especially with non power assisted clutches, faster shifts, and less clutch wear.

Double clutching allows the driver to control the engine and transmission revolutions to synchronize, so that a smooth shift can be made e.g. when upshifting, accelerator pedal is released and the clutch pedal is depressed while the gear lever is moved in to neutral, clutch pedal is then released and quickly pushed down again while the gear lever is moved to the next highest gear. Finally, the clutch pedal is released and accelerator pedal pushed down to obtain required engine rpms. Although this is a relatively fast movement perhaps a second or so while transmission is in neutral it allows the engine speed to drop and synchronize engine and transmission revolutions relative to the road speed. Downshifting is performed in a similar fashion except the engine speed is now required to increase (while transmission is in neutral) just a right amount in order to achieve the synchronisation for the smooth non-crunching gearchange. The so called skip changing is also widely used, in principle operation is the same but it requires neutral be held slightly longer than single gearchange.

Common North American setups include 9, 10, 13, 15, and 18 speeds. Automatic and semi-automatic transmissions for heavy trucks are becoming more and more common, due to advances both in transmission and engine power. In Europe 8, 10 and 12 gears are common on larger trucks with manual transmission, while automatic or semiautomatic transmission would have anything from 5 to 12 gears. Almost all heavy trucks transmissions are of a "range (double H shift pattern ) and split" type where range change and so called half gears or splits are air operated and always preselected before the main gears selection.

In Europe more new trucks are being bought with automatic or semi-automatic transmission. This may be due the fuel consumption can be lowered and truck durability improved. The primary reason perhaps is the fact that such transmissions give a driver more time to concentrate on the road and traffic conditions.


A truck frame consists of two parallel boxed (tubular) or C-shaped rails, or beams, held together by crossmembers. These frames are referred to as ladder frames due to their resemblance to a ladder if tipped on end. The rails consist of a tall vertical section (two if boxed) and two shorter horizontal flanges. The height of the vertical section provides opposition to vertical flex when weight is applied to the top of the frame (beam resistance). Though typically flat the whole length on heavy duty trucks, the rails may sometimes be tapered or arched for clearance around the engine or over the axles. The holes in rails are used either for mounting vehicle components and running wires and hoses, or measuring and adjusting the orientation of the rails at the factory or repair shop.

Though they may be welded, crossmembers are most often attached to frame rails by bolts or rivets. Crossmembers may be boxed or stamped into a c-shape, but are most commonly boxed on modern vehicles, particularly heavy trucks.

The frame is almost always made of steel, but can be made (whole or in part) of aluminium for a lighter weight. A tow bar may be found attached at one or both ends, but heavy trucks almost always make use of a fifth wheel hitch.

Environmental effects

Trucks contribute to air, noise, and water pollution similarly to automobiles. Trucks may emit lower air pollution emissions than cars per pound of vehicle mass, although the absolute level per vehicle mile traveled is higher and diesel soot is especially problematic for health. With respect to noise pollution trucks emit considerably higher sound levels at all speeds compared to typical car; this contrast is particularly strong with heavy-duty trucks.

Concerns have been raised about the effect of trucking on the environment, particularly as part of the debate on global warming. In the period from 1990 to 2003, carbon dioxide emissions from transportation sources increased by 20%, despite improvements in vehicle fuel efficiency.

In 2005, transportation accounted for 27% of U.S. greenhouse gas emission, increasing faster than any other sector.

Between 1985 and 2004, in the U.S., energy consumption in freight transportation grew nearly 53%, while the number of ton-miles carried increased only 43%. "Modal shifts account for a nearly a 23% increase in energy consumption over this period. Much of this shift is due to a greater fraction of freight ton-miles being carried via truck and air, as compared to water, rail, and pipelines."

According to a 1995 U.S. Government estimate, the energy cost of carrying a ton of freight a distance of one kilometer averages 337 kJ for water, 221 kJ for rail, 2 000 kJ for trucks and nearly 13 000 kJ for air transport. and many environment organizations favor laws and incentives to encourage the switch from road to rail, especially in Europe.

Usage and types

Trucks are mainly used for cargo transport.

Trucks have been created for specific tasks such as for mixing and transporting concrete, and light trucks for the military to use as troop carriers.

Quality and sales

Quality among all heavy truck manufacturers in general is improving, however industry insiders will testify that the industry has a long way to go before they achieve the quality levels reached by automobile manufacturers. Part of the reason for this is that 75% of all trucks are custom specified. This works against efforts to streamline and automate the assembly line.

Heavy trucks market worldwide

Largest manufacturers in Western Europe, the U.S. and Japan, over 16 tonnes GVW in 2005.
Pos. Make Units
1 Daimler AG (Mercedes-Benz,Freightliner,Sterling,Unimog,Western Star,Fuso) 241,515
2 Volvo (Volvo,Mack,Renault,UD Nissan Diesel) 177,106
3 PACCAR (DAF Trucks,Kenworth,Peterbilt,Leyland Trucks) 124,406
4 Navistar International Corporation (International,Workhorse) 61,066
5 MAN 53,379
6 Scania 53,365
7 Hino Motors (Toyota Group) 44,494
8 Iveco (Iveco,Magirus,Astra,Seddon Atkinson,Yuejin) 43,364
9 Nissan Diesel 25,852
10 Volkswagen 22,684



Heavy truck leading manufacturers:

South America

Registrations of heavy trucks in South America (2002; % breakdown by manufacturer):

North America

On the East Coast, where routes were shorter, and because the trucks were made there, many drivers preferred Mack Trucks. On the West Coast, the drivers preferred Peterbilt, Kenworth, and Freightliner. White built a new factory in California in the early 1960s, with long-haul trucking company Consolidated Freightways. The entity, which became White-Freightliner, then just Freightliner, catered directly to western fleets that wanted a lighter, aluminium cab and frame, and traveled longer distances without stopping. Drivers more concerned with safety than with fuel economy preferred the heavier Peterbilts and Kenworths. Kenworth and Peterbilt, which had started out as heavy-duty trucks for hauling logs, forest products, and steel for shipyards on the West Coast, anticipated the need for these lighter long-distance trucks.


  • SNVI (ALGERIA) different models for the Algerian market and some African and Asian countries)


  • Volvo (Australia)
  • Mack (Australia)
  • Iveco (different models for Australian market)
  • Kenworth (different models for Australian market)

Insuring trucks for commercial hauling

Primary Liability Insurance coverage protects the truck from damage or injuries to other people as a result of a truck accident. This truck insurance coverage is mandated by U.S. state and federal agencies and proof of coverage is required to be sent to them. Insurance coverage limits range from $35,000 to $1,000,000. Pricing is dependent on region, driving records, and history of the trucking operation.

Motor Truck Cargo insurance protects the transporter for his responsibility in the event of damaged or lost freight. The policy is purchased with a maximum load limit per vehicle. Cargo insurance coverage limits can range from $10,000 to $100,000 or more. Pricing for this insurance is mainly dependent on the type of cargo being hauled.

Truck shows

In the UK, three truck shows are popular - Shropshire Truck Show in Oswestry Showground during May, The UK Truck Show held in June at Santa Pod Raceway and FIA European Drag Racing Championships from the home of European Drag-Racing. The UK Truck Show features drag-racing with 6-ton trucks from the British Truck Racing Association, plus other diesel-powered entertainment.

Truck Shows provide operators with an opportunity to win awards for their trucks.

See also


  • Conduire un véhicule lourd, Société de l'Assurance Automobile du Québec, 7e édition, 2002 ISBN 2-551-19567-5

External links

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