Will the new Green E10 petrol cost you dear?

Posted on October 19th, 2018 by Rob Marshall

Will the new Green E10 petrol cost you dear?

The government consultation (which lasted for fewer than two months) closed on the 16th September. In it, the Department of Transport (DfT) sought public feedback on whether and how to introduce E10 petrol in the UK, in what way to label the new fuel, plus for how long a continued supply of the ‘traditional’ E5 petrol should be maintained for the c.635,000 cars that are incompatible with the new petrol blend.


What is E5 and E10 petrol?
Currently, petrol is blended with a maximum of 5% ethanol, which is derived not from crude oil but plants. The current proposals wish to raise the alcohol content to 10%. The government loves it, because it helps it to comply with the EU-set biofuel directive and environmental groups are in favour; according to the DfT, E10 would reduce an average car’s CO2 emissions by 2%.


It sounds great – what is the catch?

5% ethanol in petrol tends to be the maximum level at which damage will not occur, generally. Yet, increasing the percentage raises the risk of fuel leaks, fire and fuel system corrosion. These safety issues are created by the increased ethanol content attacking various rubbers and metals used in fuel systems of older cars. The safety risk affects mainly Historic Vehicles, although some vehicles made up to 2004 may be incompatible as well. All new cars from 2011 had to be E10-compliant legally but, in reality, most cars produced after 2000 should not experience such issues. Here is a list of cars that are known to be compatible. Double-check with your carmaker, if you are unsure.


Yet, I share a few other reservations that do not seem to have been considered in detail, even on compatible vehicles. Many small but high performance modern turbocharged engines are suffering from internal damage due to LSPI (low speed pre-ignition, or ‘knock’) and the research that I have seen on how E10-blended 95 octane petrol influences knock and the resultant engine damage in the real world appears to be inconclusive. I welcome any experts in the field to make contact via our Facebook page, to further my knowledge in this area.

Additionally, ethanol tends to absorb water and some onlookers are concerned about E10 not lasting well in storage, because the ethanol separates from the fuel itself, which could increase the risk of breakdowns and engine/fuel system damage in all cars, not just older ones.

Presuming that the fuel was not left long enough to go ‘stale’ at the fuel station before being dispensed, this would effect vehicles mainly that are not used often, unless low-mileage owners choose to run their fuel tanks as low as possible all of the time, which itself introduces further issues.

The real-world environmental benefits of E10 are also questionable. While the CO2 emissions that are associated with its production are highlighted by critics (although consider that producing and transporting petrol also has CO2 implications), E10 is expected to make your car’s fuel consumption increase by around 3%, due to the lower energy content of the alcohol, compared to petrol. This might obviate the earlier mentioned CO2 saving of 2% quoted by the DfT. Interestingly, the DfT is quoted and criticised by Vivergo (the UK’s largest biofuel producer) for saying that “E10’s impact on air quality (that is exhaust emissions that exclude CO2) is ‘negligible’.

So, E10 is likely to make you fill-up more often and, as ethanol costs more to produce, it could be more expensive. Therefore, expect fuel prices to rise – unless government decides to cut duty on E10 (and not just cynically hike tax on E5) to make it more attractive to the general public, which is unlikely. Several organisations claim that the main way for widespread public acceptance is to cut fuel duty for the new petrol significantly, which the public purse is unlikely to stomach.


Is it worth it?

Any move to reduce road transport’s impact on the environment has to be lauded. Yet, too many questions about the real-world environmental and safety credentials of E10 remain, when balanced with informing the public about the fuel and avoiding any potential backlash, such as that experienced in Germany during 2011. Additionally, the government is proposing that the current E5 petrol will be available only until 2020, which is insufficient time and could force many older vehicles off the road.

A benefit of the consultation, however, is that the UK Government can demonstrate to the EU that it is making proactive moves to comply with the EU Biofuels and Renewable Energy Directives, by altering its own Road Transport Fuels Obligation and seeking to introduce E10. Yet, with the current political situation, this might be a smoke-and-mirrors display, by moving to introduce the fuel but not doing so, if the EU is unable to penalise any non-compliance.

I will blog on the result of the DfT’s consultation, when it is made available.