Compared to OHV pushrod systems with the same number of valves, the reciprocating components of the OHC system are fewer and have a lower overall mass. Though the system drives the camshafts may be more complex, most engine manufacturers accept that added complexity as a trade-off for better engine performance. The fundamental reason for the OHC valvetrain is that it offers an increase in the ability to exchange induction. Another performance advantage is gained as a result of the better optimised port configurations made possible with overhead camshaft designs, with no intrusive pushrods, the overhead camshaft cylinder head design can use straighter ports of more advantageous cross-section and length. The OHC design allows for higher speeds than comparable cam-in-block designs. The higher engine speeds thus allowed increases power output for a given torque output, in earlier OHC systems, including inter-war Morrises and Wolseleys, oil leaks in the lubrication systems were an issue. Single overhead camshaft is a design in which one camshaft is placed within the cylinder head, in the SOHC design, the camshaft operates the valves directly, traditionally via a bucket tappet, or via an intermediary rocker arm. SOHC cylinder heads are less expensive to manufacture than double overhead camshaft cylinder heads.
Timing belt replacement can be easier since there are fewer camshaft drive sprockets that need to be aligned during the replacement procedure, SOHC designs offer reduced complexity compared to overhead valve designs — when used for multivalve cylinder heads, in which each cylinder has more than two valves. Exhaust and inlet manifolds were both on the side of the engine block. This did, offer excellent access to the spark plugs, in the early 1980s, Toyota and Volkswagen Group used a directly actuated, SOHC parallel valve configuration with two valves for each cylinder. The Toyota system used hydraulic tappets, the Volkswagen system used bucket tappets with shims for valve clearance adjustment. Honda used a similar system in their motorcycles, using the term Unicam for the concept. This system uses one camshaft for each bank of cylinder heads, with the cams operating directly onto the valve and indirectly, through a short rocker arm. This allows a compact, light valvetrain to operate valves in a combustion chamber.
The Unicam valve train was first used in single cylinder dirt bikes, a dual overhead camshaft valvetrain layout is characterised by two camshafts located within the cylinder head, one operating the intake valves and the other one operating the exhaust valves. This design reduces valvetrain inertia more than is the case with a SOHC engine, a DOHC design permits a wider angle between intake and exhaust valves than do SOHC engines. This can allow for a less restricted airflow at higher engine speeds, DOHC with a multivalve design allows for the optimum placement of the spark plug which, in turn, improves combustion efficiency
Ferdinand Porsche was an automotive engineer and founder of the Porsche car company. He is best known for creating the first gasoline-electric hybrid vehicle, the Volkswagen Beetle, in addition, Porsche designed the 1923 Benz Tropfenwagen, which was the first racing car with a mid-engine, rear-wheel drive layout. Porsche was an important contributor to the German war effort during World War II. He was involved in the production of advanced tanks such as the VK4501, Tiger I, Tiger II, Porsche was a member of the German Nazi party and allegedly the SS. He was a recipient of the German National Prize for Art and Science, the SS-Ehrenring and he was called the Great German Engineer by Nazi propaganda. In 1996 Porsche was inducted into the International Motorsports Hall of Fame, Ferdinand Porsche was born to German-speaking parents in Maffersdorf, northern Bohemia, part of the Austrian Empire at that time, and today part of the Czech Republic. Ferdinand was his parents third child and his father, Anton Porsche, was a master panel-beater.
He showed an aptitude for mechanical work at a very early age. He attended classes at the Imperial Technical School in Reichenberg at night while helping his father in his shop by day. Thanks to a referral, Porsche landed a job with the Béla Egger Electrical company in Vienna when he turned 18, in Vienna he would sneak into the local university whenever he could after work. Other than attending classes there, Porsche never received any higher engineering education, during his five years with Béla Egger, Porsche first developed the electric hub motor. After the breakup of the Austro-Hungarian Empire at the end of World War I, in 1934 Adolf Hitler or Joseph Goebbels made Porsche a naturalized German citizen. In 1898, Porsche joined the Vienna-based factory Jakob Lohner & Company, which produced coaches for Emperor Franz Joseph I of Austria as well as for the monarchs of the UK, and Romania. Jakob Lohner had begun construction of automobiles in 1896 under Ludwig Lohner in the suburb of Floridsdorf.
Their first design was the Egger-Lohner vehicle, first unveiled in Vienna, Austria, on 26 June 1898, Porsche had engraved the code P1 onto all the key components. The Egger-Lohner was a car driven by two electric motors within the front wheel hubs, powered by batteries. This drive train construction was expanded to four-wheel drive, by mounting two more electric motors to the rear wheels, and a four-motor example was ordered by Englishman E. W. Hart in 1900. In December that year, the car was displayed at the Paris World Exhibition under the name Toujours-Contente, even though this one-off vehicle had been commissioned for the purposes of racing and record-breaking, its 1,800 kg of lead–acid batteries was a severe shortcoming
An abbreviation is a shortened form of a word or phrase. It consists of a group of letters taken from the word or phrase, a contraction is an abbreviation, but an abbreviation is not necessarily a contraction. Acronyms and initialisms are regarded as subsets of abbreviations and they are abbreviations that consist of the initial letters or parts of words. Abbreviations have a history, created so that spelling out a whole word could be avoided. This might be done to time and space, and to provide secrecy. Shortened words were used and initial letters were used to represent words in specific applications. In classical Greece and Rome, the reduction of words to single letters was common, in Roman inscriptions, Words were commonly abbreviated by using the initial letter or letters of words, and most inscriptions have at least one abbreviation. However, some could have more than one meaning, depending on their context, Abbreviations in English were frequently used from its earliest days. Manuscripts of copies of the old English poem Beowulf used many abbreviations, for example 7 or & for and, the standardisation of English in the 15th through 17th centuries included such a growth in the use of abbreviations.
At first, abbreviations were sometimes represented with various suspension signs, for example, sequences like ‹er› were replaced with ‹ɔ›, as in ‹mastɔ› for master and ‹exacɔbate› for exacerbate. While this may seem trivial, it was symptomatic of an attempt by people manually reproducing academic texts to reduce the copy time, an example from the Oxford University Register,1503, Mastɔ subwardenɔ y ɔmēde me to you. And wherɔ y wrot to you the last wyke that y trouyde itt good to differrɔ thelectionɔ ovɔ to quīdenaɔ tinitatis y have be thougħt me synɔ that itt woll be thenɔ a bowte mydsomɔ. The Early Modern English period, between the 15th and 17th centuries, had abbreviations like ye for Þe, used for the word the, hence, by misunderstanding, during the growth of philological linguistic theory in academic Britain, abbreviating became very fashionable. The use of abbreviation for the names of J. R. R. Tolkien and his friend C. S. Lewis, but before that, many Britons were more scrupulous at maintaining the French form.
In French, the period follows a abbreviation if the last letter in the abbreviation is not the last letter of its antecedent. Like many other cross-channel linguistic acquisitions, many Britons readily took this up and followed this rule themselves, while the Americans took a simpler rule and applied it rigorously. Over the years, the lack of convention in some style guides has made it difficult to determine which two-word abbreviations should be abbreviated with periods and which should not. The U. S. media tend to use periods in two-word abbreviations like United States, many British publications have gradually done away with the use of periods in abbreviations
Internal combustion engine
An internal combustion engine is a heat engine where the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combustion engine the expansion of the high-temperature and high-pressure gases produced by combustion applies direct force to some component of the engine, the force is applied typically to pistons, turbine blades, rotor or a nozzle. This force moves the component over a distance, transforming chemical energy into mechanical energy. The first commercially successful internal combustion engine was created by Étienne Lenoir around 1859, firearms are a form of internal combustion engine. Working fluids can be air, hot water, pressurized water or even liquid sodium, ICEs are usually powered by energy-dense fuels such as gasoline or diesel, liquids derived from fossil fuels. While there are many applications, most ICEs are used in mobile applications and are the dominant power supply for vehicles such as cars, aircraft.
Typically an ICE is fed with fossil fuels like natural gas or petroleum products such as gasoline, there is a growing usage of renewable fuels like biodiesel for compression ignition engines and bioethanol or methanol for spark ignition engines. Hydrogen is sometimes used, and can be made from fossil fuels or renewable energy. Various scientists and engineers contributed to the development of internal combustion engines, in 1791, John Barber developed a turbine. In 1794 Thomas Mead patented a gas engine, in 1794 Robert Street patented an internal combustion engine, which was the first to use liquid fuel, and built an engine around that time. In 1798, John Stevens built the first American internal combustion engine, in 1807, Swiss engineer François Isaac de Rivaz built an internal combustion engine ignited by electric spark. In 1823, Samuel Brown patented the first internal combustion engine to be applied industrially, in 1860, Belgian Jean Joseph Etienne Lenoir produced a gas-fired internal combustion engine.
In 1864, Nikolaus Otto patented the first atmospheric gas engine, in 1872, American George Brayton invented the first commercial liquid-fuelled internal combustion engine. In 1876, Nikolaus Otto, working with Gottlieb Daimler and Wilhelm Maybach, patented the compressed charge, in 1879, Karl Benz patented a reliable two-stroke gas engine. In 1892, Rudolf Diesel developed the first compressed charge, compression ignition engine, in 1926, Robert Goddard launched the first liquid-fueled rocket. In 1939, the Heinkel He 178 became the worlds first jet aircraft, at one time, the word engine meant any piece of machinery — a sense that persists in expressions such as siege engine. A motor is any machine that produces mechanical power, electric motors are not referred to as Engines, combustion engines are often referred to as motors. In boating an internal combustion engine that is installed in the hull is referred to as an engine, reciprocating piston engines are by far the most common power source for land and water vehicles, including automobiles, ships and to a lesser extent, locomotives
The City Municipality of Bremen is a Hanseatic city in northwestern Germany, which belongs to the state Free Hanseatic City of Bremen. As a commercial and industrial city with a port on the River Weser, Bremen is part of the Bremen/Oldenburg Metropolitan Region. Bremen is the second most populous city in Northern Germany and eleventh in Germany, Bremen is a major cultural and economic hub in the northern regions of Germany. Bremen is home to dozens of galleries and museums, ranging from historical sculptures to major art museums. Bremen has a reputation as a working class city, along with this, Bremen is home to a large number of multinational companies and manufacturing centers. Companies headquartered in Bremen include the Hachez chocolate company and Vector Foiltec, four-time German football champions Werder Bremen are based in the city. Bremen is some 60 km south from the Weser mouth on the North Sea, with Bremerhaven right on the mouth the two comprise the state of the Free Hanseatic City of Bremen.
The marshes and moraines near Bremen have been settled since about 12,000 BC, burial places and settlements in Bremen-Mahndorf and Bremen-Osterholz date back to the 7th century AD. Since The Renaissance, some scientists have believed that the entry Fabiranum or Phabiranon in Ptolemys Fourth Map of Europe, written in 150 AD, but Ptolemy gives geographic coordinates, and by these dates Phabiranon is situated northeast of the mouth of river Visurgis. At that time the Chauci lived in the now called north-western Germany or Lower Saxony. By the end of the 3rd century, they had merged with the Saxons, during the Saxon Wars the Saxons, led by Widukind, fought against the West Germanic Franks, the founders of the Carolingian Empire, and lost the war. Charlemagne, the King of the Franks, made a new law, the Lex Saxonum which stated that Saxons were not allowed to worship Odin, in 787 Willehad of Bremen became the first Bishop of Bremen. The citys first stone walls were built in 1032, around this time trade with Norway and the northern Netherlands began to grow, thus increasing the importance of the city.
The city was recognised as an entity with its own laws. Property was to be inherited without feudal claims for reversion to its original owner. This privilege laid the foundation for Bremens status of imperial immediacy, since the city was the major taxpayer, its consent was generally sought. In this way the city wielded fiscal and political power within the Prince-Archbishopric, in 1260 Bremen joined the Hanseatic League. In 1350, the number of inhabitants reached 20,000, around this time the Hansekogge became a unique product of Bremen
Chichester is a cathedral city in West Sussex, in South-East England. It is the city in West Sussex and is its county town. It has a history as a settlement from Roman times and was important in Anglo-Saxon times. It is the seat of a bishopric, with a 12th-century cathedral, Chichester has three tiers of local government. It is a hub, and a centre for culture in the county, with a theatre, museum. Chichester Harbour and the South Downs provide opportunities for outdoor pursuits, the city centre stands on the foundations of the Romano-British city of Noviomagus Reginorum, capital of the Civitas Reginorum. The Roman road of Stane Street, connecting the city with London, started at the east gate, the plan of the city is inherited from the Romans, the North, South and West shopping streets radiate from the central market cross dating from medieval times. The original Roman city wall was over 6½ feet thick with a steep ditch and it survived for over one and a half thousand years but was replaced by a thinner Georgian wall.
The city was home to some Roman baths, found down Tower Street when preparation for a new car park was under way. A museum, the Novium, preserving the baths was opened on 8 July 2012, an amphitheatre was built outside the city walls, close to the East Gate, in around 80 AD. The area is now a park, but the site of the amphitheatre is discernible as a bank approximately oval in shape. In January 2017, archaeologists using underground radar reported the discovery of the relatively untouched ground floor of a Roman townhouse, the exceptional preservation is due to the fact the site, Priory Park, belonged to a monastery and has never been built upon since Roman times. According to the Anglo-Saxon Chronicle it was captured towards the close of the century, by Ælle. It was the city of the Kingdom of Sussex. The cathedral for the South Saxons was founded in 681 at Selsey, Chichester was one of the burhs established by Alfred the Great, probably in 878-9, making use of the remaining Roman walls. The system was supported by a network based on hilltop beacons to provide early warning.
It has been suggested that one such link ran from Chichester to London, when the Domesday Book was compiled, Chichester consisted of 300 dwellings which held a population of 1,500 people. There was a mill named Kings Mill that would have been rented to local slaves and villeins
A mid-engine layout describes the placement of an automobile engine between the rear and front axles. The mid-engine layout makes ABS brakes and traction control systems work better, the mid-engine layout may make a vehicle safer, since an accident can occur if a vehicle cannot stay in its own lane around a curve or is unable to stop quickly enough. This balance is harder to achieve when the weight of the engine is located far to the front or far to the rear of the vehicle. Some automobile designs strive to balance the fore and aft weight distribution by means, such as putting the engine in the front. Another benefit comes when the mass of the engine is located close to the back of the seats. It makes it easier for the suspension to absorb the force of bumps so the riders feel a smoother ride, but in sports cars the engine position is once again used to increase performance and the potentially smoother ride is usually more than offset by stiffer shock absorbers. The largest drawback of mid-engine cars is restricted rear passenger space, the engine in effect pushes the passenger compartment forward towards the front axle.
The mid-engine layout was common in buses in the 1950s and 1960s. The Ferrari Mondial is to date the only example of a true mid-engined convertible with seating for 4. A version of the Lotus Evora with a roof panel is anticipated. Like any layout where the engine is not front-mounted and facing the wind and this has been a problem in some cars, but this issue seems to have been largely solved in newer designs. For example, the Saleen S7 employs large engine-compartment vents on the sides, mid engined cars are more dangerous than front-engined cars if the driver loses control - although this may be initially harder to provoke due to the superior balance - and the car begins to spin. Conversely, a car is more likely to break away in a progressive. The term mid-engine has usually been applied to cars having the engine located between the driver and the drive axles. This layout is referred to here as RMR layout and racing cars typically have this mid-engine layout, as these vehicles handling characteristics are more important than other features, such as capacity.
Additionally the mechanical layout and packaging of an RMR car is substantially different from that of a front engine or rear engine car, in handling and vehicle layout FMR is substantially the same as FR. Some vehicles could be classified as FR or FMR depending on the installed engine. Historically most classical FR cars such as the Ford Models T and A would qualify as a FMR engine car, not all manufacturers use the Front-Mid designation
Automotive design is the profession involved in the development of the appearance, and to some extent the ergonomics, of motor vehicles or more specifically road vehicles. This most commonly refers to automobiles but refers to motorcycles, buses, the functional design and development of a modern motor vehicle is typically done by a large team from many different disciplines included within automotive engineering. Automotive design in context is primarily concerned with developing the visual appearance or aesthetics of the vehicle. Automotive design is practiced by designers who usually have an art background, the task of the design team is usually split into three main aspects, exterior design, interior design, and color and trim design. Graphic design is an aspect of design, this is generally shared amongst the design team as the lead designer sees fit. Design focuses not only on the outer shape of automobile parts. The aesthetic value will need to correspond to ergonomic functionality and utility features as well, though not all the new vehicular gadgets are to be designated as factory standard items, some of them may be integral to determining the future course of any specific vehicular models.
The stylist responsible for the design of the exterior of the vehicle develops the proportions, Exterior design is first done by a series of digital or manual drawings. Progressively, drawings that are more detailed are executed and approved by appropriate layers of management, Clay and or digital models are developed from, and along with the drawings. The data from these models are used to create a full sized mock-up of the final design. With three- and five-axis CNC milling machines, the model is first designed in a computer program and carved using the machine. Even in times of high-class 3d software and virtual models on power walls, here the emphasis is on ergonomics and the comfort of the passengers. The procedure here is the same as with exterior design, the color and trim designer is responsible for the research and development of all interior and exterior colors and materials used on a vehicle. These include paints, fabric designs, grains, headliner, wood trim, contrast and pattern must be carefully combined to give the vehicle a unique interior environment experience.
Designers work closely with the exterior and interior designers, designers draw inspiration from other design disciplines such as, industrial design, home furnishing and sometimes product design. Specific research is done into global trends to design for two to three model years in the future. Trend boards are created from research in order to keep track of design influences as they relate to the automotive industry. The designer uses this information to develop themes and concepts that are further refined and tested on the vehicle models
Engine tuning is an adjustment, modification of the internal combustion engine, or modification to its control unit, otherwise known as its ECU. It is adjusted to yield performance, to increase an engines power output, economy. These goals may be exclusive, and an engine may be detuned with respect to output in exchange for better economy or longer engine life due to lessened stress on engine components. It has a history, almost as long as the development of the automobile in general, originating with the development of early racing cars. Tuning can describe a variety of adjustments and modifications, from the routine adjustment of the carburetor. At the other end of the scale, performance tuning of an engine can involve revisiting some of the decisions taken at quite an early stage in the development of the engine. On modern engines, equipped with electronic ignition and fuel injection, some or all of tasks are automated. A tune-up usually refers to the servicing of the engine to meet the manufacturers specifications.
Tune-ups are needed periodically as according to the recommendations to ensure an automobile runs as expected. Modern automobiles now typically only a small number of tune-ups over the course of an approximate 250. Modern engines are equipped with a management system /Engine Control Unit which can be modified to different settings. This allows for an engine to be used by several different brands. Performance tuning focuses on tuning an engine for motorsport, although many such automobiles never compete, in this context, the power output and responsiveness of the engine are of premium importance, but reliability and fuel efficiency are relevant. In particular, the transmission and any other load-transmitting powertrain components may need to be modified in order to withstand the load from the increased power, in almost all cases, people are interested in increasing the power output of an engine. Many well tried and tested techniques have been devised to achieve this, in order to check the amount of the air/fuel mixture, air fuel ratio meters are often used.
The weight of fuel will affect the overall performance of the automobile. This means that the tuning of an engine should take place in the context of the development of the overall automobile. Using larger or multiple carburetors, to create a more controllable air/fuel mixture to burn, in modern engines, fuel injection is more often used, and may be modified in a similar manner
Mercedes 24/100/140 PS
The Mercedes 24/100/140 PS was a large luxury car introduced by Daimler of Untertürkheim in 1924. Production continued until 1929 by which time Daimler had merged with Benz & Cie as a result of which the name had changed to Mercedes-Benz Typ 630. The car was conceptually and structurally similar to the contemporary Mercedes 15/70/100 PS, a still more powerful Mercedes-Benz Modell K sports car version, sometimes known as the Mercedes-Benz 24/110/160 PS, was offered between 1926 and 1929. A defining feature of the cars was the supercharger fitted to the engine. Plans for the car were drawn up by the company’s Technical Director, Paul Daimler, following an acrimonious disagreement about new model policy, Daimler left in 1922, transferring to rival manufacturer Horch. It was left to Daimler’s successor as Technical Director, arriving at the plant from Austria in April 1923, to complete the development, by the car’s launch year of 1924 Daimler had already for many years been branding their cars with the name “Mercedes”.
Otherwise the manufacturer applied the widely followed German naming conventions of the time, on the Mercedes 24/100/140 PS the “24” defined the car’s tax horsepower, used by the authorities to determine the level of annual car tax to be imposed on car owners. The “100” and the “140” both defined the manufacturer’s claims regarding car’s actual power output as defined in metric horsepower, in Germany tax horsepower, which had been defined by statute since 1906, was based on the dimensions of the cylinders in the engine. The unusual feature in the naming of this car was the inclusion of two different power output figures and this arose from the fitting to the engine of a switchable supercharger. With the device switched off maximum claimed output was of 100 PS, with the supercharger invoked, maximum output rose to 140 PS. The Mercedes 24/100/140 PS was one of two Daimler models to survive the fusion of Daimler with Benz & Cie which came into effect in 1926, many buyers will have purchased the car in bare chassis form and purchased bodywork separately from an independent coach builder.
That included the octogenarian German President whose 1929 presidential Typ 630 featured a Pullman-Landaulet body by coachbuilders Jos. Neuss of Berlin, the six cylinder in-line 6240 cc engine featured an overhead camshaft which at the time was an unusual feature, with “bevel linkage”. However, it was the supercharger, adopted from the company’s racing cars. With the device switched off maximum claimed output was of 100 PS at 3,100 rpm, with the supercharger operating, the top speed listed was 115 km/h or 120 km/h according to which of the two offered final drive ratios was fitted. Power was transmitted to the wheels via a multi-plate dry disc clutch. The suspension configuration followed the conventions of the time, using rigid beam axles, braking operated on all four wheels using a cable linkage. The car changed little during its production life. The name change to Mercedes-Benz Typ 630 which followed the Daimler/Benz fusion was not accompanied by any changes to the car, in 1928 the effectiveness of the brakes was increased through the addition of a vacuum powered support
Auto racing is a sport involving the racing of automobiles for competition. Almost as soon as automobiles had been invented, races of various sorts were organised, by the 1930s specialist racing cars had developed. There are now numerous different categories, each with different rules and it was won by the carriage of Isaac Watt Boulton. Internal combustion auto racing events began soon after the construction of the first successful gasoline-fueled automobiles, the first organized contest was on April 28,1887, by the chief editor of Paris publication Le Vélocipède, Monsieur Fossier. It ran 2 kilometres from Neuilly Bridge to the Bois de Boulogne, on July 22,1894, the Parisian magazine Le Petit Journal organized what is considered to be the worlds first motoring competition, from Paris to Rouen. One hundred and two competitors paid a 10-franc entrance fee, the first American automobile race is generally held to be the Thanksgiving Day Chicago Times-Herald race of November 28,1895. Press coverage of the event first aroused significant American interest in the automobile, brooklands, in Surrey, was the first purpose-built motor racing venue, opening in June 1907.
It featured a 4.43 km concrete track with high-speed banked corners, One of the oldest existing purpose-built automobile racing circuits in the United States, still in use, is the 2. 5-mile -long Indianapolis Motor Speedway in Speedway, Indiana. It is the largest capacity venue of any variety worldwide, with a top capacity of some 257. NASCAR was founded by Bill France, Sr. on February 21,1948, the first NASCAR Strictly Stock race ever was held on June 19,1949, at Daytona Beach, Florida. From 1962, sports cars temporarily took a seat to GT cars. From 1972 through 2003, NASCARs premier series was called the Winston Cup Series, the changes that resulted from RJRs involvement, as well as the reduction of the schedule from 48 to 31 races a year, established 1972 as the beginning of NASCARs modern era. The IMSA GT Series evolved into the American Le Mans Series, the European races eventually became the closely related Le Mans Series, both of which mix prototypes and GTs. The best-known variety of racing, Formula One, which hosts the famous Monaco Grand Prix.
In single-seater, the wheels are not covered, and the cars often have aerofoil wings front, in Europe and Asia, open-wheeled racing is commonly referred to as Formula, with appropriate hierarchical suffixes. In North America, the Formula terminology is not followed, the sport is usually arranged to follow an international format, a regional format, and/or a domestic, or country-specific, format. In North America, the used in the National Championship have traditionally been similar though less sophisticated than F1 cars. The series most famous race is the Indianapolis 500, the other major international single-seater racing series is GP2
Governments and private organizations have developed car classification schemes that are used for innumerable purposes including regulation and categorization, among others. This article details commonly used classification schemes in use worldwide, vehicles can be categorized in numerous ways. Regulatory agencies may establish a vehicle classification system for determining a tax amount, in the United Kingdom, a vehicle is taxed according to the vehicles construction, weight, type of fuel and emissions, as well as the purpose for which it is used. Other jurisdictions may determine vehicle tax based upon environmental principles, such as the user pays principle, another standard for road vehicles of all types that is used internationally, is ISO 3833-1977. In the United States, since 2010 the Insurance Institute for Highway Safety uses a scheme it has developed that takes into account a combination of both shadow and weight. The United States Federal Highway Administration has developed a scheme used for automatically calculating road use tolls.
There are two categories depending on whether the vehicle carries passengers or commodities. Vehicles that carry commodities are further subdivided by number of axles and number of units, the United States Environmental Protection Agency has developed a classification scheme used to compare fuel economy among similar vehicles. Passenger vehicles are classified based on a total interior passenger. Trucks are classified based upon their gross vehicle weight rating, heavy duty vehicles are not included within the EPA scheme. A similar set of classes is used by the Canadian EPA, in Australia, the Federal Chamber of Automotive Industries publishes its own classifications. This is a table listing several different methods of vehicle classification. Straddling the boundary between car and motorbike, these vehicles have engines under 1.0 litre, typically only two passengers, and are sometimes unorthodox in construction. Some microcars are three-wheelers, while the majority have four wheels, microcars were popular in post-war Europe, where their appearance led them to be called Bubble cars.
More recent microcars are often electric powered, the size of ultracompact cars will be less than minicars, but have engine greater than 50cc displacement and able to transport 1 or 2 persons. Ultracompact cars cannot use standard, because of strict safety standards for minicars. The regulation about running capacity and safety performance of cars will be published in early autumn. Today, there are smaller than ultracompact cars, called category-1 motorized vehicles which it has 50cc displacement or less