Unleaded Fuel Has Changed

As part of the government’s ongoing drive to reduce carbon emissions, September 1 2021 saw the standard grade of unleaded petrol switch from E5 to E10. Not all fuel stations will have made the switch immediately but, once they do, they will cease to offer the older E5 fuel. So, what exactly is E10 and how will it affect motorists filling up at the pump?

E10 fuel explained

E10 fuel is made up of 90% standard unleaded petrol and 10% ethanol that’s been generated from materials such as low-grade grains, sugars and waste wood. The change means that the amount of ethanol used has gone up from 5% to 10%.

Why is it changing?

The government estimates that the switch will reduce CO₂ emissions by as much as 750,000 tonnes. To put this figure into perspective, that’s the equivalent of taking up to 350,000 cars off the road completely.

Can all vehicles run E10 fuel?

The environment’s gain could be some motorists’ pain, as not all vehicles will be able to run the new fuel. On the plus side, all petrol cars built from 2011 onwards are E10 compatible. However, the Department for Transport (DfT) estimates that around 700,000 vehicles could have trouble running E10 fuel.

To find out if you are affected by the change, the government has launched a free compatibility checker. Before you start, you will need to know the model, engine size and year of manufacture for each vehicle you want to check. You can find this information in the vehicle’s logbook (V5C) or by entering your registration number into the DVLA’s online tool.

Will E10 fuel damage incompatible vehicles?

Most incompatible vehicles will run on the new fuel but, as times goes on, the corrosive properties of bioethanol will start to cause problems with seals, plastics, and metals. You might also notice some ‘pinking’ and a little sluggishness when starting from cold.

If you do fill up with E10 by mistake, just try and top up with the correct fuel as soon as possible. Generally, this should be when the tank is 50-75% full but try not to leave the car unused for a long period of time.

Is E10 fuel efficient?

The increased amount of ethanol means that drivers using E10 fuel in compatible vehicles will get slightly fewer miles to the gallon. The government estimates the difference at around 1% which, given variable fuel efficiencies caused by driving styles or tyre pressure, is unlikely to be particularly noticeable.

Is there any alternative to E10?

Some forecourts will still be supplying Super Unleaded E5 fuel however, with prices on average 12p per litre more expensive than regular unleaded, the increase in cost could quickly add up for higher mileage drivers.

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