Question to the Department for Transport:

To ask the Secretary of State for Transport, whether she has made a comparative assessment of the potential impact of (a) E5 and (b) E10 fuel on (i) fuel consumption and (ii) emissions.

The legislation which introduced E10 across Britain in September 2021 is the Motor Fuel (Composition and Content) and the Biofuel (Labelling) (Amendment) (No. 2) Regulations 2021.

The impact assessment accompanying these regulations estimates that moving from E5 to E10 will reduce greenhouse gas emissions by 1 .8%, saving around 750,000 tonnes of CO2 per year from petrol vehicles. Ethanol contains less energy than fossil petrol and so increasing the ethanol content of petrol increases fuel consumption. The impact assessment estimates E10 will decrease the energy content of petrol by 1.7% compared to E5 and assumes fuel consumption will increase by that amount.