Current research and development is largely centered on "hybrid" vehicles that use both electric power and internal combustion. The first hybrid vehicle available for sale in the United States was the Honda Insight, achieving around 70 miles per gallon (25.5km per liter). Other research and development efforts in alternative forms of power focus on developing fuel cells, alternative forms of combustion such as GDI and HCCI, and even the stored energy of compressed air (see Air Engine).
This engine was used to power an urban car with room for five passengers and a projected range of about 100 to 200 miles (160 to 320 km), depending on traffic conditions. The main advantages are: no roadside emissions, low cost technology, engine uses food oil for lubrication (just about 1 liter, changes only every 30,000 miles (50,000 km) and integrated air conditioning. Range could be quickly tripled, since there are already carbon fiber tanks which have passed safety standards holding gas at 10,000 lbf/in² (70 MPa).
The tanks may be refilled in about three minutes at a service station, or in a few hours at home plugging the car into the electric grid via an on-board compressor. The cost of refilling is projected to be about US$3.
Battery Electric Vehicles (BEVs) are electric vehicles whose main energy storage is in the chemical energy of batteries. BEVs are the most common form of what is defined by the California Air Resources Board (CARB) as zero emission (ZEV) passenger automobiles, because they produce no emissions while being driven. The electrical energy carried onboard a BEV to power the motors is obtained from a variety of battery chemistries arranged into battery packs. For additional range genset trailers or pusher trailers are sometimes used, forming a type of hybrid vehicle. Batteries used in electric vehicles include "flooded" lead-acid, absorbed glass mat, NiCd, nickel metal hydride, Li-ion, Li-poly and zinc-air batteries.
Attempts at building viable, modern battery-powered electric vehicle began in the 1950s with the introduction of the first modern (transistor controlled) electric car - the Henney Kilowatt. Despite the poor sales of the early battery-powered vehicles, development of various battery-powered vehicles continued through the 1960(notably General Motors with the EV1), but cost, speed and inadequate driving range continued to make them impractical. Battery powered cars have primarily used lead-acid batteries and NiMH batteries. Lead-acid batteries' recharge capacity is considerably reduced if they're discharged beyond 75% on a regular basis, making them a less-than-ideal solution. NiMH batteries are a better choice, but are considerably more expensive than lead-acid. Lithium-ion battery powered vehicles such as the Venturi Fetish have recently demonstrated excellent performance and range, but they remain very expensive.
The first commercial vehicle that used ethanol as a fuel was the Ford Model T, produced from 1908 through 1927. It was fitted with a carburetor with adjustable jetting, allowing use of gasoline or ethanol, or a combination of both. Other car manufactures also provided engines for etanol fuel use. In the United States, alcohol fuel was produced in corn-alcohol stills until Prohibition criminalized the production of alcohol in 1919. The use of alcohol as a fuel for internal combustion engines, either alone or in combination with other fuels, lapsed until the oil price shocks of the 1970s. Furthermore, additional attention was gained because of its possible environmental and long-term economical advantages over fossil fuel.
Both ethanol and methanol have been use as an automotive fuel. While both can be obtained from petroleum or natural gas, ethanol has attracted more attention because it is considered a renewable resource, easily obtained from sugar or starch in crops and other agricultural produce such as grain, sugarcane or even lactose. Since ethanol occurs in nature whenever yeast happens to find a sugar solution such as overripe fruit, most organisms have evolved some tolerance to ethanol, whereas methanol is toxic. Other experiments involve butanol, which can also be produced by fermentation of plants. Support for ethanol comes from the fact that it is a biomass fuel, which addresses climate change and greenhouse gas emissions, though these benefits are now highly debated, including the heated 2008 food vs fuel debate.
Ethanol has the property of slowly decomposing certain rubber compounds such as are found in the fuel lines and seals used in vehicles produced before the mid 1980s. Also, because gasoline is more volatile than ethanol, it can be harder to start some engines using higher ethanol percentages than they were designed to use, especially when the engine is cold during the winter. Ethanol is also electrically conductive (gasoline is an effective insulator) which can cause problems with some early electric fuel pump designs and fuel tank sensors. Corrosion of magnesium and aluminium parts is also a concern at higher ethanol percentages. Most modern cars are designed to run on gasoline are capable of running with a blend from 10% up to 15% ethanol mixed into gasoline (E10-E15). With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85% (E85), the maximum set in the United States and Europe due to cold weather during the winter, or up to 100% (E100) in Brazil, with a warmer climate. Ethanol has close to 34% less energy per volume than gasoline, consequently fuel economy ratings with ethanol blends are significantly lower than with pure gasoline, but this lower energy content does not translate directly into a 34% reduction in mileage, because there are many other variables that affect the performance of a particular fuel in a particular engine, and also because ethanol has a higher octane rating which is beneficial to high compression ratio engines.
For this reason, for pure or high ethanol blends to be attractive for users, its price must be lower than gasoline to offset the lower fuel economy. As a rule of thumb, Brazilian consumers are frequently advised by the local media to use more alcohol than gasoline in their mix only when ethanol prices are 30% lower or more than gasoline, as ethanol price fluctuates heavily depending on the results and seasonal harvests of sugar cane and by region. In the US, and based on EPA tests for all 2006 E85 models, the average fuel economy for E85 vehicles was found 25.56% lower than unleaded gasoline. The EPA-rated mileage of current American flex-fuel vehicles could be considered when making price comparisons, though E85 has octane rating of about 104 and could be used as a substitute for premium gasoline. Regional retail E85 prices vary widely across the US, with more favorable prices in the Midwest region, where most corn is grown and ethanol produced. In August 2008 the US average spread between the price of E85 and gasoline was 16.9%, while in Indiana was 35%, 30% in Minnesota and Wisconsin, 19% in Maryland, 12 to 15% in California, and just 3% in Utah. Depending of the vehicle capabilities, the break even price of E85 usually has to be between 25 to 30% lower than gasoline. (See price comparisons for most states at e85prices.com)
Reacting to the high price of oil and its growing dependence on imports, in 1975 Brazil launched the Pro-alcool program, a huge government-subsidized effort to manufacture ethanol fuel (from its sugar cane crop) and ethanol-powered automobiles. These ethanol-only vehicles were very popular in the 1980s, but became economically impractical when oil prices fell - and sugar prices rose - late in that decade. In May 2003 Volkswagen built for the first time a commercial ethanol flexible fuel car, the Gol 1.6 Total Flex. These vehicles were a commercial success and by 2008 other nine Brazilian manufacturers are producing flexible fuel vehicles: Chevrolet, Fiat, Ford, Peugeot, Renault, Honda, Mitsubishi, Toyota and Citröen. The adoption of the flex technology was so rapid, that flexible fuel cars reached 87.6% of new car sales in July 2008. As of August 2008, the fleet of "flex" automobiles and light commercial vehicles had reached 6 million new vehicles sold, representing almost 19% of all registered light vehicles. The rapid success of "flex" vehicles, as they are popularly known, was made possible by the existance of 33,000 filling stations with at least one ethanol pump available by 2006, a heritage of the Pro-alcool program.
In the United States, initial support to develop alternative fuels by the government was a also response to the oil crisis, and later on, as a goal to improve air quality. Also, liquid fuels were preferred over gaseous fuels not only because they have a better volumetric energy density but also because they were the most compatible fuels with existing distribution systems and engines, thus avoiding a big departure from the existing technologies and taking advantage of the vehicle and the refueling infrastructure. California led the search of sustainable alternatives with interest in methanol. In 1996, a new FFV Ford Taurus was developed, with models fully capable of running either methanol or ethanol blended with gasoline. This ethanol version of the Taurus was the first commercial production of a E85 FFV. The momentum of the FFV production programs at the American car companies continued, although by the end of the 90's, the emphasis was on the FFV E85 version, as it is today. Ethanol was preferred over methanol because there is a large support in the farming community and thanks to government's incentive programs and corn-based ethanol subsidies. Sweden also tested both the M85 and the E85 flexifuel vehicles, but due to agriculture policy, in the end emphasis was given to the ethanol flexifuel vehicles.
Today the most common commercially available FFV in the market is the ethanol flexible-fuel vehicle, with around 13 million vehicles on the road around the world by mid-2008, concentrated in the United States (6.8 million),Brazil (6 million), and Europe, led by Sweden (116 thousand).
The main benefit of Diesel combustion engines is that they have a 40% fuel burn efficiency; compared with just 25-30% in the best gasoline engines. In addition diesel fuel has slightly higher Energy Density by volume than gasoline. This makes Diesel engines capable of achieving much better fuel economy than gasoline vehicles.
Biodiesel is commercially available in most oilseed-producing states in the United States. As of 2005, it is somewhat more expensive than fossil diesel, though it is still commonly produced in relatively small quantities (in comparison to petroleum products and ethanol). Many farmers who raise oilseeds use a biodiesel blend in tractors and equipment as a matter of policy, to foster production of biodiesel and raise public awareness. It is sometimes easier to find biodiesel in rural areas than in cities.
Some Diesel-powered cars can run with little or no modification on 100% pure biodiesel, a fuel that can be made from vegetable oils. Vegetable oils tend to solidify in cold weather conditions so vehicle modifications may be required in order to heat the fuel prior to use under those circumstances. Modern low emission diesels (most often Euro -3 and -4 compliant), typical of the current production in the European industry, require extensive modification of injector system, pumps and seals etc. due to the higher operating pressures. The result is sensitive lubrication & sealing systems that bio diesel fuels do not protect and may even attack. This reduces the market for bio diesels as increasing numbers of new vehicles are not able to use it.
Biodiesel has lower Energy Density than fossil diesel fuel or gasoline, so biofueled vehicles are not quite able to keep up with the fuel economy of a fossil fueled diesel vehicle. But they're still better than 4 stroke gasoline engines, and they aren't burning fossil fuels.
High pressure compressed natural gas, mainly composed of methane, that is used to fuel normal combustion engines instead of gasoline. Combustion of methane produces the least amount of CO2 of all fossil fuels. Gasoline cars can be retrofitted to CNG and become bifuel NGV Natural gas vehicles as the gasoline tank stays. You can switch between CNG and gasoline during operation.
Worldwide, as of 2006 there are roughly 5 million natural gas vehicles (NGVs), with the largest number of NGVs in Argentina, Brazil, Iran, Pakistan and Thailand. In Europe they are popular in Germany and Italy.
CNG vehicles are commonly used in South America, where these vehicles are mainly used as taxicabs in main cities of Argentina and Brazil. Normally, standard gasoline vehicles are retrofitted in specialized shops, which involve installing the gas cylinder in the trunk and the CNG injection system and electronics. By 2006 there were more than a 1.2 million retrofitted vehicles in Brazil, with a higher concentration in the cities of Rio de Janeiro and São Paulo. In 2006 the Brazilian subsidiary of FIAT introduced the Fiat Siena Tetra fuel, a four-fuel car developed under Magneti Marelli of Fiat Brazil. This automobile can run on 100% ethanol (Common ethanol fuel mixtures#E100), Common ethanol fuel mixtures#E25 (Brazil's normal ethanol gasoline blend), pure gasoline (not available in Brazil), and natural gas, and switches from the gasoline-ethanol blend to CNG automatically, depending on the power required by road conditions. Other existing option is to retrofit an ethanol flexible-fuel vehicle to add a natural gas tank and the corresponding injection system. Some taxicabs in São Paulo and Rio de Janeiro, Brazil, run on this option, allowing the user to choose among three fuels (E25, E100 and CNG) according to current market prices at the pump. Vehicles with this adaptation are known in Brazil as tri-fuel cars.
A small number of prototype hydrogen cars currently exist, and a significant amount of research is underway to make the technology more viable. The common internal combustion engine, usually fueled with gasoline (petrol) or diesel liquids, can be converted to run on gaseous hydrogen. However, the most efficient use of hydrogen involves the use of fuel cells and electric motors instead of a traditional engine. Hydrogen reacts with oxygen inside the fuel cells, which produces electricity to power the motors. One primary area of research is hydrogen storage, to try to increase the range of hydrogen vehicles while reducing the weight, energy consumption, and complexity of the storage systems. Two primary methods of storage are metal hydrides and compression. Some believe that hydrogen cars will never be economically viable and that the emphasis on this technology is a diversion from the development and popularization of more efficient hybrid cars and other alternative technologies.
High speed cars, buses, motorcycles, bicycles, submarines, and space rockets already run on hydrogen, in various forms. There is even a working toy model car that runs on solar power, using a reversible fuel cell to store energy in the form of hydrogen and oxygen gas. It can then convert the fuel back into water to release the solar energy.
BMW's Clean Energy internal combustion hydrogen car has more power and is faster than hydrogen fuel cell electric cars. A limited series production of the 7 Series Saloon was announced as commencing at the end of 2006. A BMW hydrogen prototype (H2R) using the driveline of this model broke the speed record for hydrogen cars at 300 km/h (186 mi/h), making automotive history. Mazda has developed Wankel engines to burn hydrogen. The Wankel uses a rotary principle of operation, so the hydrogen burns in a different part of the engine from the intake. This reduces pre-detonation, a problem with hydrogen fueled piston engines.
The other major car companies like Daimler, Chrysler, Honda, Toyota, Ford and General Motors, are investing in hydrogen fuel cells instead. VW, Nissan, and Hyundai/Kai also have fuel cell vehicle protoypes on the road. In addition, transit agencies across the globe are running prototype fuel cell buses. Fuel cell vehicles, such as the new Honda Clarity, can get up to 70 miles on a kilogram of hydrogen (roughly equivalent to a gallon of gasoline.)
A solar car is an electric vehicle powered by solar energy obtained from solar panels on the car. Solar cars are not a practical form of transportation; insufficient power falls on the roof of a practically sized and shaped vehicle to provide adequate performance. They are raced in competitions such as the World Solar Challenge and the North American Solar Challenge. These events are often sponsored by Government agencies such as the United States Department of Energy keen to promote the development of alternative energy technology such as solar cells and electric vehicles. Such challenges are often entered by universities to develop their students engineering and technological skills as well as motor vehicle manufacturers such as GM and Honda.
The North American Solar Challenge is a solar car race across North America. Originally called Sunrayce, organized and sponsored by General Motors in 1990, it was renamed American Solar Challenge in 2001, sponsored by the United States Department of Energy and the National Renewable Energy Laboratory. Teams from universities in the United States and Canada compete in a long distance test of endurance as well as efficiency, driving thousands of miles on regular highways.
Nuna is the name of a series of manned solar powered vehicles that won the World solar challenge in Australia three times in a row, in 2001 (Nuna 1 or just Nuna), 2003 (Nuna 2) and 2005 (Nuna 3). The Nunas are built by students of the Delft University of Technology.
The World solar challenge is a solar powered car race over 3021 km through central Australia from Darwin to Adelaide. The race attracts teams from around the world, most of which are fielded by universities or corporations although some are fielded by high schools.
A steam car is a car that has a steam engine. Wood, coal, ethanol, or others can be used as fuel. The fuel is burned in a boiler and the heat converts water into steam. When the water turns to steam, it expands. The expansion creates pressure. The pressure pushes the pistons back and forth. This turns the driveshaft to spin the wheels forward. It works like a coal-fueled steam train, or steam boat. The steam car was the next logical step in independent transport.
Steam cars take a long time to start, but some can reach speeds over 100 mph (161 km/h) eventually. the late model doble could be brought to operational condition in less than 30 seconds, and were fast, with high acceleration, but they were ridiculously expensive.
A steam engine uses external combustion, as opposed to internal combustion. Gasoline-powered cars are more efficient at about 25-28% efficiency. In theory, a combined cycle steam engine in which the burning material is first used to drive a gas turbine can produce 50% to 60% efficiency. However, practical examples of steam engined cars work at only around 5-8% efficiency.
The best known and best selling steam-powered car was the Stanley Steamer. It used a compact fire-tube boiler under the hood to power a simple two-piston engine which was connected directly to the rear axle. Before Henry Ford introduced monthly payment financing with great success, cars were typically purchased outright. This is why the Stanley was kept simple; to keep the purchase price affordable.
Steam power can be combined with a standard oil-based engine to create a hybrid. Water is injected into the cylinder after the fuel is burned, when the piston is still superheated, often at temperatures of 1500 degrees or more. The water will instantly be vaporized into steam, taking advantage of the heat that would otherwise be wasted.
Wood gas can be used to power cars with ordinary internal combustion engines if a wood gasifier is attached. This was quite popular during World War II in several European and Asian countries because the war prevented easy and cost-effective access to oil.
A flexible-fuel vehicle (FFV) or dual-fuel vehicle is an alternative fuel automobile or light duty truck with a multifuel engine that can use more than one fuel, usually mixed in the same tank, and the blend is burned in the combustion chamber together. These vehicles are colloquially called flex-fuel, or flexifuel in Europe, or just flex in Brazil. FFVs are distinguished from bi-fuel vehicles, where two fuels are stored in separate tanks. The most common commercially available FFV in the world market is the ethanol flexible-fuel vehicle, with the major markets concentrated in the United States, Brazil, Sweden, and some other European countries. In addition to flex-fuel vehicles running with ethanol, in the US and Europe there were successful test programs with methanol flex-fuel vehicles, known as M85 FFVs, and more recently there have been also successful tests using p-series fuels with E85 flex fuel vehicles, but as of June 2008, this fuel is not yet available to the general public.
Ethanol flexible-fuel vehicles have standard gasoline engines that are capable of running with ethanol and gasoline mixed in the same tank. These mixtures have "E" numbers which describe the percentage of ethanol in the mixture, for example, E85 is 85% ethanol and 15% gasoline. (See common ethanol fuel mixtures for more information.) Though technology exists to allow ethanol FFVs to run on any mixture up to E100, in the U.S. and Europe, flex-fuel vehicles are optimized to run on E85. This limit is set to avoid cold starting problems during very cold weather. The alcohol content might be reduced during the winter, to E70 in the U.S. or to E75 in Sweden. Brazil, with a warmer climate, developed vehicles that can run on any mix up to common ethanol fuel mixtures#E100, though common ethanol fuel mixtures#E20 is the mandatory minimum blend, and no pure gasoline is sold in the country.
The US has the biggest fleet of flex-fuel vehicles in the world, with 6.8 million as of February 2008, followed by Brazil with 6.0 million as of August 2008. However, the actual number of American FFVs using E85 is much lower, as surveys conducted in the US have found that 68% of American flex-fuel car owners were not aware they owned an E85 flex. This is due to the fact that the exterior of flex and non-flex vehicles look exactly the same; there is no sale price difference between them; the lack of consumer's awareness about E85s; and also the decision of American automakers of not putting any kind of exterior labeling, so buyers can be aware they are getting an E85 vehicle. In contrast, all Brazilian automakers put a visible fixture or decal in the exterior body, with some variant of the prefix "flex" to clearly identify the flex-fuel models. As of 2007, new FFV models feature a yellow gas cap with the label "E85/gasoline" written on the cap, in order to remind drivers of the E85 capabilities.. Use of E85 is also affected by the relative low number of E85 filling stations across the country, as just over 1,750 were available by August 2008, and highly concentrated in the Corn Belt states, led by Minnesota with 353 stations, followed by Illinois with 181, and Wisconsin with 114.
Also, there have been claims that American automakers are producing E85 flex models motivated by a loophole in the CAFE (Corporate Average Fuel Economy) requirements, that allows for a fuel economy credit for every flex-fuel vehicle sold, whether or not in practice these vehicles are fueled with E85. This loophole might allow the car industry to meet the CAFE targets in fuel economy just by spending between USD 100 to USD 200 that it cost to turn a conventional vehicle into a flex-fuel, without investing in new technology to improve fuel economy, and saving them the potencial fines for not achieving that standard in a given model year.
In the United States E85 flexible-fuel vehicles use a technology that allows the fuel mixture to be automatically detected by one or more sensors, and once detected, the ECU tunes the timing of spark plugs and fuel injectors so that the fuel will burn cleanly in the vehicle's internal combustion engine. Originally, sensors in both the fuel-line and in the exhaust system were used for flexible fuel vehicles. In recent years, manufacturers have instead opted to use only sensors in the exhaust manifold, before the catalytic converter, and to eliminate the fuel inline sensor. A separate small storage tank for gasoline used for a cold starting the engine in early US models is no longer required.
Brazilian flex-fuel technology developed an engine capable of running on any blend between common ethanol fuel mixtures#E20 gasohol to Common ethanol fuel mixtures#E100, and uses the lambda probe to measure the quality of combustion in conventional engines, so informing the engine control unit (ECU) which blend of gasoline and alcohol is being actually burned. This task is accomplished automatically through software developed by Brazilian engineers, called "Software Fuel Sensor" (SFS), fed with data from the standard sensors already built-in the vehicle, avoiding the need for an additional dedicated sensor to monitor the ethanol-gasoline mix. The technology was developed by the Brazilian subsidiary of Bosch in 1994, but was further improved and commercially implemented in 2003 by the Italian subsidiary of Magneti Marelli, located in Hortolândia, São Paulo. A similar fuel injection technology was developed by the Brazilian subsidiary of Delphi Automotive Systems, and it is called "Multifuel", based on research conducted at its facility in Piracicaba, São Paulo. This technology allows the controller to regulate the amount of fuel injected and spark time, as fuel flow needs to be decreased and also self-combustion needs to be avoided when gasoline is used because ethanol engines have compression ratio around 12:1, too high for gasoline.
A hybrid vehicle uses multiple propulsion systems to provide motive power. This most commonly refers to gasoline-electric hybrid vehicles, which use gasoline (petrol) and electric batteries for the energy used to power internal-combustion engines (ICEs) and electric motors. These powerplants are usually relatively small and would be considered "underpowered" by themselves, but they can provide a normal driving experience when used in combination during acceleration and other maneuvers that require greater power.
The Toyota Prius is one of the world's first commercially mass-produced and marketed hybrid automobiles. Manufactured by Toyota, the Prius first went on sale in Japan in 1997. The car was introduced to the worldwide market in 2000 and almost 160,000 units had been produced for sale in Japan, Europe, and North America as of the end of 2003. As of May 15th, 2008 Toyota had announced that it had reached a sales figure surpassing the mark of one million units. Toyota Press Release
The Honda Insight is a 2-seater hatchback hybrid automobile manufactured by Honda. It was the first mass-produced hybrid automobile sold in the United States, introduced in 1999, and produced until 2006. Honda now offers the Civic as an optional hybrid.