A tractor unit , also known as a truck unit , lorry unit , power unit , prime mover , ten-wheeler , semi-tractor , semi-truck , semi-lorry , tractor cab , truck cab , lorry cab , big rig tractor , big rig truck or big rig lorry or simply a tractor , truck , lorry , semi , big rig or rig , is a characteristically heavy-duty towing engine that provides motive power for hauling a towed or trailered load. These fall into two categories: heavy- and medium-duty military and commercial rear-wheel-drive semi-tractors used for hauling semi-trailers , and very heavy-duty typically off-road -capable, often 6×6 , military and commercial tractor units, including ballast tractors .
31-665: A ctive T ime (regional) The Iveco Stralis is a heavy-duty truck produced by the Italian manufacturer Iveco between 2002-2019. The Stralis replaced the EuroStar and EuroTech models; it covers the range above the Eurocargo , between 19 and 44 tonnes. The fire version of the Stralis released with the German based Iveco Magirus . In 2007, the Stralis received minor changes to cabin and front of
62-529: A multi-ratio transmission (10, 13, or 18 gears) for maximum flexibility in gearing. The tractor–trailer combination distributes a load across multiple axles while being more maneuverable than an equivalently sized rigid truck . The most common trailer attachment system is a fifth-wheel coupling , allowing a rapid shift between trailers performing different functions, such as a bulk tipper and box trailer . Trailers containing differing cargos can be rapidly swapped between tractors, eliminating downtime while
93-464: A certain amount of weight must be spread over driven axles, which led to heavier varieties having six-wheel drive , otherwise, another tractor unit would have to be used. Heavy haulage variants of tractor-units are often turned into a ballast tractor by fitting temporary ballast, which may require special permitting. Gross vehicle weight rating Vehicle weight is a measurement of wheeled motor vehicles; either an actual measured weight of
124-459: A class C1 licence. Anyone with a class C licence can drive class C1 vehicles. In the United States, three important GVWR limitations are 6,000, 8,500, and 26,000 pounds [lb] (2,722, 3,856, and 11,793 kg). Vehicles over 6,000 lb are restricted from some city roadways, although it is not always clear if this restriction is for actual curb weight or GVWR. Commercial vehicles over
155-633: A different class of licence is required. A vehicle with a GVM up to 4,500 kg is termed a light vehicle, while those over 4,500 kg are termed heavy vehicles. Many models of small trucks are manufactured to have a GVM rating of 5,000 to 7,000 kg (11,023 to 15,432 lb) but sold with the option of a GVM of just under 4,500 kg so that they can be driven on a car licence. Many minor roads, including some in rural areas and some in suburban areas, have GVM restrictions such as 5,000 kg or 8,000 kg. These restrictions may be applied for technical reasons such as load limited bridges, or as
186-484: A high performance decompression exhaust brake known as Iveco Turbobrake. This truck-related article is a stub . You can help Misplaced Pages by expanding it . Tractor unit It should not be confused with a tractor-trailer which is a combination of a tractor unit and semi-trailer , whereas a tractor unit describes only the tractor portion. Tractor units typically have large-displacement diesel engines for power, durability, and economy; several axles ; and
217-470: A method of reducing the number of heavy vehicles on local roads. A standard car driving licence issued by an EU country (i.e. class B) limits the licence-holder to driving vehicles with a "maximum authorised mass" (i.e. GVWR) of 3,500 kg (7,700 lb). This includes holders of UK class B driving licences who passed their driving tests on or after 1 January 1997. A UK driving licence holder who passed his or her class B driving test in or before 1996
248-527: A trailer is unloaded or loaded. Drawbar couplings are also found, particularly in dedicated exceptionally heavy-duty ballast tractors and as a means to connect intermediate fifth-wheel dollies for pulling multiple semi-trailers. Most tractor units are based on the chassis of a large truck (Class 8 in North America) minus the cargo body, with shorter frames used for cabovers and day-cab tractors, and longer frames used for Sleeper cab tractors, to accommodate
279-403: A trailer with a Gross Trailer Weight over 10,000 lb (4,536 kg) where the combined weight ratings of the vehicle and trailer are greater than 26,000 lbs. Laws vary from state to state, but typically vehicles over 10,000 lb are required to stop at weigh stations . Sometimes large passenger or non-commercial vehicles such as RVs are exempt from this. Additionally, many states use
310-561: A vehicle is rated to tow by the manufacturer. In the United States and Canada, the static tongue load, the weight of the trailer as measured at the trailer coupling, is generally recommended to be 10–15% of the GTWR. In the United States and Canada, there are four main weight classes of trailer hitches as defined by the Society of Automotive Engineers (SAE): The gross combined weight rating or gross combination weight rating (GCWR), also referred to as
341-440: Is larger and includes the maximum payload of passengers and cargo. This definition may differ from definitions used by governmental regulatory agencies or other organizations. For example, many European Union manufacturers include the weight of a 75-kilogram (165 lb) driver and luggage to follow European Directive 95/48/EC. Organizations may also define curb weight with fixed levels of fuel and other variables to equalize
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#1732858759959372-443: Is limited to driving vehicles with a GVWR of 7,500 kg (16,500 lb) or less, including minibuses not used for hire or reward. Anyone looking to drive a heavy goods vehicle (i.e. any vehicle other than those used for passenger transport) with a GVWR of over 7,500 kg (16,500 lb) must obtain a class C licence. Anyone looking to drive any vehicle with a GVWR of up to 3,500–7,500 kg (7,700–16,500 lb) must obtain
403-469: Is no standardized way to test the dry weight of a motorcycle. Inconsistencies will almost always be found between a motorcycle manufacturer's published dry weight and motorcycle press and media outlet's published dry weight. This is due to different testing techniques, differences in what is being excluded, and a lack of defining how testing was conducted by the organization doing the testing. The gross vehicle weight rating (GVWR), or gross vehicle mass (GVM),
434-477: Is significantly less than the weight of a vehicle in a drivable condition and therefore rarely used. Quoting a dry weight can make a car's weight and power-to-weight figures appear far more favorable than those of rival cars using curb weight . The difference between dry weight and curb weight depends on many variables such as the capacity of the fuel tank. There is no standard for dry weight, so it's open to interpretations. Some vehicle manufacturers have used
465-445: Is the maximum operating weight/mass of a vehicle as specified by the manufacturer including the vehicle's chassis, body, engine, engine fluids, fuel, accessories, driver, passengers and cargo but excluding that of any trailers . The weight of a vehicle is influenced by passengers, cargo, even fuel level, so a number of terms are used to express the weight of a vehicle in a designated state. Gross combined weight rating (GCWR) refers to
496-480: The fourth power of the axle weight. This means that doubling the axle weight will increase road damage (2x2x2x2)=16 times. For this reason, trucks with a high axle weight are heavily taxed in most countries. Examples of GAWR on common axles: In the EU and U.S. legal maximum load restrictions are placed on weight, independent of the manufacturer's rating. In the EU a tractor can generally have 10 tonnes (22,000 lb) on
527-631: The 8,500 lb threshold are required to have insurance under the Motor Carrier Act of 1980 and 49 CFR 387.303 . Vehicles or combinations with a GVWR over 26,000 lb (11,793 kg) generally require a Commercial Driver License (CDL) or a Non-Commercial Class "A" or "B" license. A CDL is also required for certain vehicles under 26,000 lb GVWR, such as buses and for-hire passenger vehicles of 16 or more passengers, all vehicles transporting placarded hazardous materials or wastes regardless of weight or load class, and any vehicle towing
558-656: The GVWR for registration purposes, where over a certain weight such as 8,000 lb, a mill rate is applied to the GVWR to arrive at a registration fee. . On vehicles designed for the North American market, the GVWR can be found alongside other vehicle technical specifications on the Vehicle ID Plate that is usually located on the interior of the B-pillar according to U.S. or Canadian Federal Motor Vehicle Safety Standards (inside
589-472: The capacity of the radiator , and the ability of the chassis to withstand that torque. The gross axle weight rating (GAWR) is the maximum distributed weight that may be supported by an axle of a road vehicle. Typically, GAWR is followed by either the letters FR or RR, which indicate front or rear axles respectively. Road damage rises steeply with axle weight, and is estimated "as a rule of thumb... for reasonably strong pavement surfaces" to be proportional to
620-405: The driven axle. The 6×6 units have three axles, all can be driven, and 8×6 units have four axles, with either the rear three driven and the front axle not, or the front and rear-most two axles powered and an unpowered lifting center axle to spread the load when needed. The 8×8 units also have four axles, but with all of them driven, and 10×8 units have five axles with the rear four usually driven and
651-427: The driver's door, near the door latch). Most U.S. and Australian commercial trucks are required by licensing authorities to have this information printed on the outside of the vehicle, and for it to be clearly visible from a specified distance. The gross trailer weight rating (GTWR) is the total mass of a road trailer that is loaded to capacity, including the weight of the trailer itself, plus fluids and cargo, that
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#1732858759959682-440: The front axle for steering. All five axles of 10×10 units are driven. The front two axles are usually both steer axles. The axle configurations are usually based on axle load legislation, and maximum gross vehicle weight ratings (BDM). Heavier versions of tractor units, such as those used in heavy haulage and road trains , tend to have four or more axles, with more than two axles driven. In certain countries (such as Switzerland),
713-424: The gross combination mass (GCM), gross train weight (GTW), is the maximum allowable combined mass of a road vehicle, the passengers and cargo in the tow vehicle, plus the mass of the trailer and cargo in the trailer. This rating is set by the vehicle manufacturer. The GCWR is a function of the torque output of the engine, the capacity and ratios of the transmission , the capacity of the driving axles and tires ,
744-418: The longer cabin. There have been three common cab configurations used in tractors, two are still widely used. A tractor unit can have many axles depending on axle load legislation . The most common varieties are those of 4×2, 6×2, and 6×4 types . However, some manufacturers offer 4×4, 6×6, 8x4, 8×6, 8×8, 10×8, and 10×10 axle configurations. A 6×4 has three axles, normally an undriven front steer axle and
775-445: The term shipping weight , which refers to the vehicle in as-built, no-option condition. This would include engine oil, coolant, brake fluid and at least some small quantity of fuel, as vehicles have traditionally been driven off the assembly line and these fluids were necessary to do so. The dry weight of a motorcycle excludes some or all of the following: gasoline (or other fuel), engine oil, coolant, brake fluid, or battery . There
806-401: The total mass of a vehicle including all trailers. GVWR and GCWR are used to specify weight limitations and restrictions. Gross trailer weight rating specifies the maximum weight of a trailer and the gross axle weight rating specifies the maximum weight on any particular axle. A car driver licence is limited to driving vehicles up to a maximum GVM of 4,500 kg (9,921 lb). Beyond this,
837-479: The two rear axles driven. 6×4 units are more common in long-distance haulage in larger countries such as the United States and Australia. In Europe , the 4×2 and 6×2 variants are more commonplace. Tractors with three axles or more can have more than one steering axle, which can also be driven. Most 6×2 units allow the undriven rear axle to be raised when lightly loaded, or running without a trailer, to save tire wear, save toll road fees, and increase traction on
868-419: The value for the comparison of different vehicles. The EU-directive actually defines Mass in running order, not curb-weight. Mass in running order is without the 75kg driver mentioned above. Definition of mass in running order stated in the directive. The United States Environmental Protection Agency regulations define curb weight as follows: Curb weight means the actual or the manufacturer's estimated weight of
899-421: The vehicle in operational status with all standard equipment, and weight of fuel at nominal tank capacity, and the weight of optional equipment computed in accordance with §86.1832–01; incomplete light-duty trucks shall have the curb weight specified by the manufacturer. For a motorcycle, wet weight is the equivalent term. Dry weight is the weight of a vehicle without any consumables, passengers, or cargo. It
930-466: The vehicle under defined conditions or a gross weight rating for its weight carrying capacity. Curb weight (American English) or kerb weight (British English) is the total mass of a vehicle with standard equipment and all necessary operating consumables such as motor oil , transmission oil, brake fluid , coolant , air conditioning refrigerant, and sometimes a full tank of fuel, while not loaded with either passengers or cargo. The gross vehicle weight
961-719: The vehicle. All models have the EuroTronic gearbox, which have full or semi-automatic modes. The original Stralis, introduced in 2002, was the first heavy truck with an automated gearbox as standard equipment. An updated version known as Stralis Hi-Range debuted in 2012, featuring Euro 6 engines, improved cabin ergonomics and facelifted design. It was available with three different cabs: Hi-Way (long haul sleeper), Hi-Road (sleeper) and Hi-Street (day cab). All engines are four-valve straight-6 with modern pump nozzle injection. Different performance levels from three different capacity variants are available: All engines are equipped with