As the percentage blend of ethanol increases, so its corrosive impact increases and over about 10 percent susceptible conventional vehicle components(particularly the rubber elements) need to be replaced by ethanol resistant components. However, with biodiesel this problem is reduced. In the United States, the most common blend is B20, but in Germany Austria and Sweden 100 per cent pure blended biodiesel is used in goods vehicles and buses with only very minor engine modifications(EA, 2004). Vehicles that can use conventional fuel or any blend of biofuels are known as flexible-fuel vehicles(sometimes called flex-fuel vehicles) One of the main reasons why biofuels have gained so much attention is that low blends generally agreed to be up to about 10percent) can be used directly in existing cars with no engine modifications, and the refuelling infrastructure is exactly the same as for conventional fuel(ie through fuel pumps) In early 2008, there were 165 biodiesel and 16 stations around the UK(Anon, 2008). This makes it very convenient and cheap compared with the development of other renewable fuel alternatives(such as hydrogen, electric power or L which require major modifications to both vehicles and refuelling distribution systems.