E75 in Sweden from November until March. Brazilian flex fuel vehicles are optimized to run on any mix of E20-E25 gasoline and up to 100% hydrous ethanol fuel (E100). The Brazilian flex vehicles are built-in with a small gasoline reservoir for cold starting the engine when temperatures drop below . An improved flex motor generation was launched in 2009 which eliminated the need for the secondary gas tank. 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