"Petrol is changing,” according to the government, and many of us will need to pay attention. It’s all about E numbers: never mind which chemicals are in your packet of Angel Delight, it’s the ingredients keeping your car going that you need to know, and the new concoction is called E10.
Here’s the E-based backstory. In order to make conventional fuels less bad, it was decided to blend in some renewable content such as biodiesel and ethanol. This is nothing new: it has been going on with petrol and diesel in the UK for the past 10 years. Apparently, blending renewable fuels in this way has contributed to a CO2 emissions reduction equal to taking more than a million cars off the road.
The labelling has never been terribly clear, but presently petrol is called E5 (up to 5% ethanol) and diesel B7 (up to 7% biodiesel).
The label we now have to look for on the pump reads E10. This is a biofuel made up of 90% regular unleaded and 10% ethanol, hence the name.
Ethanol is an alcohol-based fuel that’s produced from a range of plants, including sugar cane and grains. The upside is that, unlike regular unleaded petrol, ethanol actually absorbs CO2, partially offsetting greenhouse gas emissions.
The SMMT estimated that 92.2% of the petrol-engined vehicles in the UK are compatible with E10. Since 2011, all new cars sold in this country have had to be E10-compatible.
Vehicles manufactured from 2019 onwards usually have an E5 and E10 label close to their fuel filler caps, showing which fuels they can accept. So what’s the problem? Well, drivers of cars registered before 2002 have been advised not to use E10 in their vehicles, because problems have been reported.
Research carried out by our sister title What Car? revealed that E10 is potentially less efficient than the current E5 blend of petrol, with the problem being worse in smaller-engined vehicles. Drivers of shopping cars would end up filling their cars more often, which isn’t the point of owning a small car with a tiny engine.