Flexible-fuel Vehicle - Terminology

Terminology

As ethanol FFVs became commercially available during the late 1990s, the common use of the term "flexible-fuel vehicle" became synonymous with ethanol FFVs. In the United States flex-fuel vehicles are also known as "E85 vehicles". In Brazil, the FFVs are popularly known as "total flex" or simply "flex" cars. In Europe, FFVs are also known as "flexifuel" vehicles. Automakers, particularly in Brazil and the European market, use badging in their FFV models with the some variant of the word "flex", such as Volvo Flexifuel, or Volkswagen Total Flex, or Chevrolet FlexPower or Renault Hi-Flex, and Ford sells its Focus model in Europe as Flexifuel and as Flex in Brazil. In the US, only since 2008 FFV models feature a yellow gas cap with the label "E85/Gasoline" written on the top of the cap to differentiate E85s from gasoline only models.

Flexible-fuel vehicles (FFVs) are based on dual-fuel systems that supply both fuels into the combustion chamber at the same time in various calibrated proportions. The most common fuels used by FFVs today are unleaded gasoline and ethanol fuel. Ethanol FFVs can run on pure gasoline, pure ethanol (E100) or any combination of both. Methanol has also been blended with gasoline in flex-fuel vehicles known as M85 FFVs, but their use has been limited mainly to demonstration projects and small government fleets, particularly in California.

• Bi-fuel vehicles. The term flexible-fuel vehicles is sometimes used to include other alternative fuel vehicles that can run with compressed natural gas (CNG), liquefied petroleum gas (LPG; also known as autogas), or hydrogen. However, all these vehicles actually are bi-fuel and not flexible-fuel vehicles, because they have engines that store the other fuel in a separate tank, and the engine runs on one fuel at a time. Bi-fuel vehicles have the capability to switch back and forth from gasoline to the other fuel, manually or automatically. The most common available fuel in the market for bi-fuel cars is natural gas (CNG), and by 2008 there were 9,6 million natural gas vehicles, led by Pakistan (2.0 million), Argentina (1.7 million), and Brazil (1.6 million). Natural gas vehicles are a popular choice as taxicabs in the 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.

• Multifuel vehicles are capable of operating with more than two fuels. In 2004 GM do Brasil introduced the Chevrolet Astra 2.0 with a "MultiPower" engine built on flex fuel technology developed by Bosch of Brazil, and capable of using CNG, ethanol and gasoline (E20-E25 blend) as fuel. This automobile was aimed at the taxicab market and the switch among fuels is done manually. In 2006 Fiat introduced the Fiat Siena Tetra fuel, a four-fuel car developed under Magneti Marelli of Fiat Brazil. This automobile can run as a flex-fuel on 100% ethanol (E100); or on E-20 to E25, Brazil's normal ethanol gasoline blend; on pure gasoline (though no longer available in Brazil since 1993, it is still used in neighboring countries); or just on natural gas. The Siena Tetrafuel was engineered to switch from any gasoline-ethanol blend to CNG automatically, depending on the power required by road conditions. Another existing option is to retrofit an ethanol flexible-fuel vehicle to add a natural gas tank and the corresponding injection system. This option is popular among taxicab owners in São Paulo and Rio de Janeiro, Brazil, allowing users 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.

• Flex-fuel hybrid electric and flex-fuel plug-in hybrid are two types of hybrid vehicles built with a combustion engine capable of running on gasoline, E-85, or E-100 to help drive the wheels in conjunction with the electric engine or to recharge the battery pack that powers the electric engine. In 2007 Ford produced 20 demonstration Escape Hybrid E85s for real-world testing in fleets in the U.S. Also as a demonstration project, Ford delivered in 2008 the first flexible-fuel plug-in hybrid SUV to the U.S. Department of Energy (DOE), a Ford Escape Plug-in Hybrid, which runs on gasoline or E85. GM announced that the Chevrolet Volt plug-in hybrid, launched in the U.S. in late 2010, would be the first commercially available flex-fuel plug-in capable of adapting the propulsion to several world markets such as the U.S., Brazil or Sweden, as the combustion engine can be adapted to run on E85, E100 or diesel respectively. The Volt is expected to be flex-fuel-capable in 2013. Lotus Engineering unveiled the Lotus CityCar at the 2010 Paris Motor Show. The CityCar is a plug-in hybrid concept car designed for flex-fuel operation on ethanol, or methanol as well as regular gasoline.