E10: How ethanol’s cleaning up gasoline

The key to understanding E10 is to realize that the E stands for ethanol, as E10 is made up of 90% regular unleaded fuel and 10% bioethanol. Many people will have heard of ethanol as a simple alcohol, and we apply ‘bio’ in this case because most of the world’s fuel ethanol is obtained from plants.

The chief benefit of using E10 fuel is that it can lower harmful emissions, as research has confirmed bioethanol’s carbon footprint and greenhouse gas reduction benefits. These advantages are partly due to the way fuel ethanol is produced, and partly because it offers greater energy efficiency with a higher octane rating than regular gasoline. Octane ratings are measures of fuel stability – the higher the octane rating, the better the fuel burns. And E10’s superiority has been responsible for it becoming the reference fuel against which new cars have been tested for emissions and performance since 2016, while car enthusiasts may be inspired by the elite motorsport series Formula 1 changing its fuel to E10 this year in an effort to reduce carbon dioxide (CO2) emissions.

The UK is one of the current areas of E10 focus because all of the nation has made this fuel its standard as of this month, and the government hopes E10 could help cut transport CO2 emissions by 750,000 tonnes per year. Yet, the UK has several other case studies to refer to. For instance, almost all U.S. gasoline was blended with 10% bioethanol as long ago as 2016, while E10 had become the top-selling petrol in France by 2017. More recently, E10 use in India has been rising, and Brazil has for a long time used much higher percentages of bioethanol in its fuel than E10.

But E10 has also faced some challenges. For example, sales of E10 fell in Germany in 2016 because of concerns that it is not suitable for all cars, despite being able to boast a price advantage. While nearly all vehicles manufactured after 2000 can be fueled using E10, older models need to be modified. And an even bigger issue facing Germany and the rest of the world is the price of fuel. Although bioethanol has been cheaper this year than straight gasoline, and E10 is usually cheaper than E5 (with 5% ethanol) in the UK, concerns have been raised that E10 may lower a car’s fuel economy compared with E5. The rising price of fuel generally will inevitably lead to more drivers considering alternatives such as electric and hydrogen-powered vehicles. Looking further ahead, the European Union has agreed that new cars must be emissions-free after 2035, casting doubt on fuel ethanol’s long-term future.

Yet, the transition to an emissions-free global transport ecosystem will be gradual, and E10 is helping to reduce emissions during this shift. Even just in Europe, let’s take a look at the potential impact if every car used E10 fuel.