Feature: E10 petrol, is it worth it?

From September 1st 2021, E10 petrol became readily available at all UK petrol stations as part of the government’s plan to ‘build back greener.’ Air Quality News investigates the true environmental benefits of this roll out.  

What is E10?  

Up until the start of this month, the standard petrol grade in the UK was E5, meaning the petrol contains around 5% ethanol. Ethanol is a biofuel, meaning unlike fossil fuels it is produced from the fermentation of crops such as sugar or wheat and so inevitably it has a substantially lower carbon footprint.  In a bid to capitalize on the carbon savings that come from using biofuels and in order to comply with the 2008 Renewable Transport Fuel Obligation, the government has now increased the standard petrol-grade to contain 10% ethanol – known as E10 petrol.  

Andy Eastlake, chief executive officer at Zemo Partnership, the organisation who have worked with the government on the ongoing E10 marketing campaign explains: ‘Over the years, the focus when it comes to the decarbonisation of transport has been on the technology of the vehicles. But another  piece of the jigsaw is looking to see whether we can decarbonise the fuel.’  

According to the government, the introduction of E10 could cut carbon dioxide (CO2) emissions by 350,000 tonnes every single year, equivalent to the annual CO2 uptake of a forest the size of the Isle of Wight.  

Climate concerns  

However, various environmental groups have expressed concerns around these claims. Greg Archer, UK director of campaign group Transport & Environment (T&E) tells Air Quality News: ‘The problem with ethanol is how are these biofuels produced in the first place? 

‘For example, wheat that would otherwise have been going to the wheat market is now being used for biofuels, and that means that somebody elsewhere is going to have to grow that wheat. ‘Ethanol also needs an awful lot of land to produce a very small amount of fuel and so you have this problem of indirect land use change. 

‘We also know that to tackle our climate problems we are going to have to do a lot of reforestation, so increasing the amount of crops used for fuel is in effect taking up land that could otherwise be used for far more constructive purposes.’  

However, according to Andy Eastlake, under the Renewable Transport Fuels Obligation not only does the government assess the greenhouse gas impact of the biofuels, but they also assess the indirect land use change impact.  

‘The UK bioethanol market is very robust,’ he explains.  

‘In the UK we have a very transparent way of looking at biofuels and what we’re doing at Zemo is trying to encourage fuel companies to use the highest quality biofuels, meaning those that have the highest greenhouse gas savings and are of the best credibility.  

‘There are some very significant bioethanol plants here in the UK and so there is also a jobs and growth agenda, the more biofuels we can produce in the UK the better.’ 


However, with the electrification of road transport well underway, T&E has also expressed concern that these biofuels would be better used elsewhere. For example there is a strong call for the use of biofuels in the aviation and shipping industries where we do not currently have any renewable alternatives to fossil fuels.  

‘We simply don’t need biofuels in road vehicles,’ says Greg Archer.  

‘The Department for Transport says that we need to save carbon wherever we can and of course there is truth in that. But if the trucking industry becomes focused on supplying high-blend biofuels, then they’re not focused on making the switch to zero-emission vehicles, and we need to understand that without this, we will run out of time.  

‘The government seems adamant to keep raising the targets for biofuels, but in reality we need more policies to wean cars off combustion engines.’  

However, Andy Eastlake highlights that with over 19 million petrol and diesel vehicles still on the road, we are still a long way off a fully electrified fleet and so there continues to be a place for intermediate solutions.  

‘Even though E10 will result in a relatively small carbon reduction per vehicle, if you times that by 19 million vehicles, then that is equivalent to taking 350,000 vehicles off the road,’ he explains.  

‘This is not a replacement for electrification, this is a way of reducing the carbon impact on the way to an electrified fleet. We believe that whatever vehicles are on the road should be running on the lowest carbon version of the fuel that they are compatible with.’ 


Another major concern with the rollout of E10 is the compatibility of certain vehicles. According to research conducted by the RAC Foundation, there are an estimated 600,000 vehicles on the road which are not compatible with E10.  

Ivo Wengred, researcher and data manager at the RAC Foundation who helped to conduct this research explains: ‘We took all the consumer information available and tried to derive an answer of whether or not you or I would be willing to put E10 in that vehicle.  

‘There are two main ways that a vehicle can be non-compliant, the first one is if your manufacturer says no because the engine simply was not designed for this amount of ethanol in the petrol. Or the other way is if you simply cannot get the information from the manufacturer.  

‘This might sound strange but there are plenty of manufacturers out there who have either gone bust, or there is just simply no one to call. 

‘Putting E10 petrol in a non-compliant vehicle isn’t a death sentence, it’s not going to kill the vehicle immediately, but in the end it can lead to something catastrophic.’  

In a bid to prevent situations like this, and to avoid what happened in Germany where the E10 rollout had to be revoked after confusion led the majority of drivers to refuse to buy it, the government has spent £730,000 on a nationwide marketing campaign, with adverts explaining what E10 is and encouraging drivers to check if their vehicle is compliant.  

Drivers of non-compliant vehicles will still be able to purchase E5, but at an increased price, with it now coming in the form of ‘super unleaded’ premium fuels.  

Even though the compatibility of vehicles is a genuine concern for many drivers, Andy Eastlake explains: ‘In 2010 it became mandatory for every new petrol vehicle to be compatible with E10. Therefore the biggest area of concern when it comes to compatibility is someone who is using a 20-year old car to get to work, but who cannot afford a new one. 

‘However, another piece of the argument is that the cars that aren’t compatible are certainly nowhere near as efficient as a newer car. So if you’re doing a high mileage in an older car, then you should probably be thinking about upgrading it anyway, these kinds of vehicles are not Clean Air Zone compliant, they’re high-emissions.’ 

Going forward  

It is clear that for the majority of drivers, the switch to E10 will come at little cost and the roll out does have the potential to deliver some unignorable climate benefits.  

But with the latest Intergovernmental Panel on Climate Change (IPCC) Report warning that without ‘immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach,’ it does beg the question, do we have time for intermediate solutions and would this funding be better spent on improving our electric vehicle infrastructure or encouraging active travel? 

As stated by Greg Archer: ‘20 years ago, maybe it would have been fine to develop some intermediate technologies. But we don’t have time for intermediate solutions anymore. We need net-zero solutions now.’  

 This article first appeared in the Air Quality News magazine, click here to read more. 


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