Increasing the share of bioethanol in petrol by blending up to 10 per cent, known as E10, could provide significant carbon savings, helping us meet our climate change commitments. One of the main barriers to introducing E10 has been vehicle compatibility. Currently, around 95% of petrol cars used in the UK can use E10, but around 700,000 are not warranted by their manufacturers to use E10. This number is expected to decrease as vehicles come to the end of their life. However, some classic and cherished vehicles that are not advised to use E10 will remain in use.
The prolonged use of E10 fuel in those older and classic vehicles not under manufacturer warranty can cause corrosion of some rubbers and alloys used in the engine and fuel systems. For those vehicles, the Department remains committed to ensuring that E5 is retained as a protection grade, if E10 is introduced.