Figure 1	Figure 2

  With these many options available to the consumer, there are also opportunities for a repair facility to become exposed to different types of vehicle fuel systems. The two most recent fuel system introductions are the gasoline-electric hybrid and vehicles capable of burning ethanol-blended fuels, E85 being the most common (see Figure 1). It is important for collision repair technicians to know the differences between blended fuels and what can go wrong when servicing vehicles with ethanol-blended fuel.
 Ethanol is an alcohol derived from corn and is used, in general, for two basic reasons: economics and to reduce pollutants introduced into the environment. Ethanol is mixed with fuel in three common formula ratios, though depending on your location in the world, the common ratios can be different.
Fuel Ratios
 Fuel ratios are expressed in the mixture of ethanol to gasoline, with the letter “E” and a number. The number indicates the percent of ethanol in the fuel mixture (see Figure 2).
 E10, which is a mixture of 10% ethanol and 90% gasoline, can be used in internal combustion engines of most modern vehicles. E10 is available in North America and the only type of gasoline sold in Minnesota, along with E85. As of the Spring of 2006, due to the phasing out of methyl tertiary butyl ether (MTBE), which was used as a gasoline additive in the place of lead, E10 has become common throughout North America.
 Similar blends to E10 include E5 and E7, which are generally safe for engines that run on pure gasoline. Some regions mandate that locally sold fuels contain at least some ethanol. It is in this situation where these smaller ratio fuels may be sold.
 E15 (15% ethanol/85% gasoline) is generally the highest ratio of ethanol to gas that is recommended by vehicle makers selling vehicles in North America in vehicles that do not carry the designation of E85 or flex-fuel.
 E20 (20% ethanol/80% gasoline) is not yet widely used in North America, but will be mandated by Minnesota for all gasoline sold by 2013. Since February 2006, E20 is the required mixture for all gasoline sold in Brazil.
 E85 (85% ethanol/15% gasoline) is generally the highest ethanol fuel mixture found in the U.S. It is common in Sweden, and is gaining in popularity across North America.
 E95 contains just 5% gasoline and is used in some diesel engines where high compression is used to ignite the fuel, as opposed to the operation of gasoline engines where spark plugs are used. This is because as octane ratings increase, compression ratios must also increase to cause the fuel to ignite.
 E100 is straight ethanol used in Brazil and Argentina. Ignition in temperatures below 15 C (59 F ) causes problems when using pure or neat ethanol. A common cold-weather solution is adding a small gasoline reservoir to increase the gasoline content momentarily so ignition can occur and the engine can start. Once started, the engine can be operated on pure ethanol. In Brazil, ethanol fuel is hydrated ethyl alcohol, which is a mixture of 96% ethanol and 4% water. This distillation creates the purest form of ethanol.
 To clearly know which vehicles are designed to operate on which types of fuel, refer to the vehicle owner’s manual, fuel fill cap, signage on the vehicle, or vehicle maker’s service information.