Will my car run on E10 fuel? Why the new fuel might damage your car

Transport secretary Grant Shapps made the announcement this morning, revealing that the government was consulting on whether to make it the standard grade at British filling stations from 2021. Ethanol absorbs carbon dioxide, and by increasing the percentage in UK fuels, he estimated a reduction of CO2 emissions by about 750,000 tonnes per year – equivalent to taking 350,000 cars off the road.

Currently, UK fuels only contain up to five per cent ethanol (E5), whereas the E10 blend, which contains 90 per cent regular unleaded and 10 per cent ethanol, is offered at petrol stations across the EU.

But drivers of older cars have been left alarmed at the announcement, for the standardisation of such ‘biofuel’ could physically rule their car redundant. While new cars sold in the UK since 2011 have had to be E10 compatible, the Society of Motor Manufacturers and Traders (SMMT) has estimated almost 8 per cent of petrol-engined vehicles in the UK are not compatible with E10. In fact, according to the RAC, 'owners of cars registered prior to 2002 are advised not to use E10 in their vehicle, as problems have been reported'. Such problems are said to include damage to seals, plastics and metals, caused by bioethanol's corrosive properties due to its high water content.

Many carburetted cars, or those that previously ran on leaded fuel, are included in this warning, while some turbocharged or performance vehicles require a minimum octane rating of 95 or 98 and so should not be refuelled with E10.

It’s an alarming reality for many classic car owners, and while the Department for Transport has now confirmed that E5 fuels will remain available from 2021, it is as yet unknown whether they will command a premium. Motorists wondering whether their car is compatible with E10 fuels should contact the manufacturer.

And while the introduction of E10 fuels will likely appease environmentalists, and help the government meet its emissions targets, it’s likely to be the little guys that take the hit. Research carried out by What Car? in 2014 revealed that E10 is potentially less efficient than the current E5, particularly in smaller-engined cars, thus increasing the cost of drivers’ annual fuel bills. 

So, with E10 looming on the horizon, what should we do? Panic buy petrol? Boycott as the Germans did in 2011? Or accept that this efficiency ailment that affects combustion engines is terminal, and enjoy the twilight of its unleaded life?