A capital “E” in motoring terms these days normally refers to electric vehicles, however, another important “E” change took place at the start of April with E10 unleaded petrol replacing E5.

The E in this case refers to the level of renewable ethanol content in the fuel, which is doubling from 5% to 10%. By increasing the concentration of bioethanol, plant based material, the CO2 emissions produced from the vehicle’s engine can be further reduced.

E10 has been the standard grade of petrol in the UK and many EU countries since 2021 and the changeover has been largely uneventful. However, the Irish government has indicated that certain older cars may require increased maintenance due to the switch over.

 A higher bioethanol content can mean increased risk of corrosion especially to rubber hoses, seals and gaskets. This could affect older vehicles manufactured before 2003 with the implementation of the Euro V standard. These cars can run on E10, but drivers need to be aware of the potential issues. It is estimated that this could affect some 24,000 petrol vehicles in Ireland.

The Department of Transport is encouraging any drivers concerned about the change to E10 to consult the website gov.ie/E10. This explains the change and includes links to a vehicle check databases.

It is not thought that any Irish fuel retailers will continue to sell E5 petrol, however, there are fuel additives available that will counteract any issues caused by the higher ethanol content.