12th July 2021

Does E10 petrol pose a threat to classic cars?

The proposed introduction of E10 petrol poses some serious challenges for owners of classic vehicles. But now, the Government is consulting on ways to preserve supplies of E5 fuel for classic cars…

After an initial consultation period, the Department of Transport has reaffirmed its intention to introduce a “greener” standard of unleaded fuel, E10, in 2021.

As part of the government’s stated target of reaching a net zero on carbon emissions by 2050, Grant Shaps, the Transport Secretary announced that a move to the E10 grade of petrol, which contains up to 10% bioethanol and could save up to 750,000 tonnes of CO2 per year. The government estimates that this would have the same effect as removing 350,000 vehicles from the road.    

But for owners of classic cars there’s a big problem on the horizon. While classic vehicles can happily run on the E5 petrol currently on sale, the new E10 fuel with its higher percentage of ethanol can cause all sorts of problems for them.

According to the Department for Transport (DfT), the potential issues include:

  • Blocked fuel filters
  • Damaged fuel pumps
  • Degradation to flexible fuel hoses
  • Corroded carburettors

Footman James asked an expert, Martin Greaves of Classic Performance Engineering, to clarify the situation for motorists.

How does E10 fuel cause problems?

“The move to change to mainly E10 fuel is a real concern for classic car owners. Ethanol in fuel has been around since 2008, and in the industry we are already seeing problems arising from the current addition of low levels of ethanol in existing fuels (even up to the 5% level). These problems include deposits blocking fine mesh fuel filters, degradation of fuel pipes and hoses and internals of carburettors suffering corrosion.

The regime required to fully empty and clean fuel systems between uses of the car is prohibitive both in terms of time and practicality, and replacing components with ethanol compatible ones may not always be economical, or in certain cases, even possible.”

How many cars will be affected?

While current estimates suggest that there are 700,000 vehicles that are incompatible with E10 fuel in regular use on the UK’s roads, the government estimates that scrappage schemes will remove the majority of these, leaving only a few of what they term “cherished and classic” vehicles.

What can owners of classic cars do?

Martin commented, "Classic cars will still be able to run on E5 petrol, as the Government has pledged that there will be continued supplies of E5 petrol when E10 goes on sale, however there is an economic sting in the tail for classic car owners, as it may only be sold in the form of ‘Super’ grade unleaded." 

The same day as the consultation was announced, the Federation of British Historic Vehicle Clubs (FBHVC) Chairman David Whale attended a meeting at the House of Commons with the All Party Parliamentary Historic Vehicles Group, chaired by Sir Greg Knight, to reinforce the concerns of the Federation’s members directly with MPs.

The following question was posed to the Secretary of State for Transport by Sir Greg Knight, Conservative MP for East Yorkshire:

"To ask the Secretary of State for Transport, what assessment he has made of the potential effect of the use of E10 fuel on older vehicles?”

Which received the following response from Rachel Maclean, Parliamentary Under-Secretary (Department for Transport):

“Increasing the share of bioethanol in petrol by blending up to 10 per cent, known as E10, could provide significant carbon savings, helping us meet our climate change commitments. One of the main barriers to introducing E10 has been vehicle compatibility. Currently, around 95% of petrol cars used in the UK can use E10, but around 700,000 are not warranted by their manufacturers to use E10. This number is expected to decrease as vehicles come to the end of their life. However, some classic and cherished vehicles that are not advised to use E10 will remain in use. The prolonged use of E10 fuel in those older and classic vehicles not under manufacturer warranty can cause corrosion of some rubbers and alloys used in the engine and fuel systems. For those vehicles, the Department remains committed to ensuring that E5 is retained as a protection grade, if E10 is introduced.”

The DfT have also said there would be a review after five years to consider whether there is a viable and widely available alternative for owners of older cars and whether continuing to sell E5 remains appropriate.

For information from the FBHVC on their position on the E10 fuels consultation, visit their website.

David Bond, Managing Director at FJ has commented, “There’s already an agreement in terms of petrol stations needing to be selling E5 petrol where there is a certain volume of petrol being sold. In time that may dwindle. But at the same time the history of cars has been about innovation, development. Manufacturers are already looking at things like synthetic fuels.”

He added: “Filling stations that stock both grades of petrol and supply at least 1million litres of fuel each year will need to make sure one product is the super E5 protection grade. So not all filling stations necessarily will be able to do that so you could see some petrol station not supplying it. But there’s still going to be plenty out there and also others are looking at additives you could put into the vehicle or whether actually the cars may run OK on E10."

Is there a downside to ‘super’ grade unleaded?

Martin commented, “The downside to this ‘super’ grade unleaded at the 5% ethanol level is that we are already seeing issues being caused at this 5% level. When these are factored in alongside the additional cost which will be levied on this fuel, it becomes a greater cause for concern."

"Aside from the mere cost, the other main concern shared by many within the industry centres around whether or not the fuel will continue to be readily and widely available in the long term."

"Overall, the low mileages covered by the average classic car owner will likely lessen any possible deleterious effects of ethanol fuel found in ‘Super’ grade unleaded, as well as minimising the actual additional cost of the ‘Super’ grade petrol."

Could E10 actually be good for your classic?

Fuel expert Paul Ireland believes the positive effects of E10 on how your classic engine runs, may actually outweigh the negatives. You can read more about his thoughts on our blog post New E10 Petrol May Mean Classics Will "Run Better".

What do you think? Let us know your thoughts in the comments below.

The information contained in this blog post is based on sources that we believe are reliable and should be understood as general information only. It is not intended to be taken as advice with respect to any specific or individual situation and cannot be relied upon as such.

I have a 1983 Mercedes, which I tried to fill up today 6.3.22 with E5 Petrol from Gainsborough Lincs. Tesco & Morrisons. Neither of which now stocks E5 fuel. Although when I searched for garages that stock these, they were both listed as doing so. I was unable to fill my car up. I don't know where to go to get this now, as the internet is not correct about where to get this. I also don't know if I can put E10 in the tank, with or without an additive. I don't want to ruin my Classic car which I have owned for the past 22yrs.

Mercedes Lady, 06/03/2022

Following the first fill up of e5 for my 1951 Land Rover, the garage took on a foul smell traced to a leaking fuel tank.

GNV, 02/01/2022

As far as I know the U.S. has been using E10 gasoline for years now with no problems.

Phil, 08/10/2021