1¼”HS2 SU Carburettors. Air Filter Gaskets. between Carburettor and Air Filter. Top Quality. To date, petrol in the UK has contained up to 5% renewable ethanol (known as E5). as fitted to the. If your vehicle is not compatible with E10 fuel, you will still be able to use E5 by purchasing the ‘Super’ grade petrol from most filling stations.