E10 Fuel and Your Motorcycle: What Does it Mean for UK Riders?



With the Government’s announcement that the UK would adopt E10 petrol as the standard grade for petrol forecourts, motorcyclists have been left in the lurch, not knowing what that means for our bikes. 

So, we have pulled together everything you need to know and laid it all out in this article.

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What is E10 fuel?

Standard unleaded petrol, also known as E5, is a combination of gasoline and up to 5% ethanol (alcohol). 

E10 fuel, however, increases the percentage of ethanol allowed to be used to 10%.

Ethanol is a renewable fuel made from crops instead of being distilled from crude oil like gasoline. 

E10 fuel is already in use in the USA and some European countries. 

Why is E10 being introduced?

In 2020 the UK Government started work on a consultation that proposed making E10 the standard fuel used as part of the first Transport Decarbonisation Plan. 

“The UK government has set ambitious targets to reduce greenhouse gas (GHG) emissions to net-zero by 2050. The transport sector accounts for the greatest share of UK GHG emissions: 27% in 2019.” Gov.uk

With the percentage of ethanol increased and ethanol being a renewable fuel, E10 is seen as a greener alternative than fuel with higher petrol formulas. 

“Switching to E10 would reduce the CO2 emissions from a petrol vehicle by around 2%… This, combined with an increase to overall renewable fuel targets, could cut overall transport CO2 emissions by a further 750,000 tonnes a year – the equivalent of taking around 350,000 cars off the road.”

So the switch to E10 is part of the Government’s plan to reduce greenhouse gas emissions.

It is one of the first steps while technology in electric vehicles continues to develop and be made more affordable for all. 

What are the problems with E10 fuel?

E10 fuel doesn’t come without issues; while the consultation documents focus on cars, many of the same problems caused will affect motorbikes. 

Here are the main problems:

Vehicles need to use more of it

E10 fuel contains less energy than E5 or pure petrol. 

As a result, engines will need to burn more fuel to achieve the same performance. 

Euractiv states that a Finnish magazine Tekniikan Maailma found that in lab tests, E10 increases fuel consumption by 3% compared to E5. 

What Car in 2014 said that E10 fuel could increase fuel consumption in some vehicles by 10%. 

Essentially, this means that fuel will end up being more expensive, with motorists needing to buy more of it on a more regular basis. 

Vehicle compatibility is an issue

When E5 fuel was introduced, the 5% ethanol content was thought to be the maximum that engines and fuelling systems used to traditional petrol could cope with without damage or affecting performance. 

Therefore, the increase to 10% ethanol content poses a risk to some vehicles, particularly older models. 

The ethanol content can cause corrosion to rubber and alloys used in the engine and fuel systems. 

The Government is fairly dismissive of this issue; as older cars are scrapped and newer ones replace them, the problem resolves itself.

The focus, however, is very much on cars with no mention of motorcycles. 

Compatibility and motorcycles specifically

Ethanol burns at a different rate than petrol. In cars with a catalytic converter and lambda sensor in the exhaust, it isn’t an issue, and the sensor tells the fuel injection system when to kick in. 

Cars have had this set up for around the last 20 years. 

However, motorcycles weren’t quite so quick to catch up with the emissions laws, so the same technology didn’t start to get put into place until 2010. 

This means that any motorcycle produced before 2010 won’t have the technology to help counteract the air/fuel ratio that higher percentage ethanol fuel needs for the bike to run right. 

E10 also poses a further problem for motorbikes as ethanol absorbs water, going as far as to suck it in from the air around it. 

As we motorcyclists know, we spend hours trying to protect our bikes from water, as water is a pest and can cause all sorts of rust/corrosion issues. 

Water content is a big reason ethanol can cause corrosion in engines and fuel systems. 

Components never meant to be exposed to water are now faced with it. 

Another problem is that ethanol is a solvent. Hence, parts made of rubber, fibreglass, and plastic intended to only be in contact with pure petrol, such as fuel tanks, now run the risk of serious damage and even melting. 

Many older motorcycles have plastic fuel tanks, posing a serious issue.  

The overriding question for all of us is, will the switch to E10 damage our bikes?

Will E10 damage my motorbike?

It is very early, and the long-term effects of using E10 fuel in new or older bikes are unknown. 

Based on what we know from how ethanol works, at the moment, we can only surmise that it is not going to be a great outcome for some bikes.

If you are riding your bike regularly, it would be pretty safe to assume that any water attracted in by the ethanol is burnt through as you ride your bike as it doesn’t have time to hang around and cause lasting damage. 

This may become a problem when a bike sits dormant for long periods with petrol in the tank. 

E10 can go stale more quickly than other fuels where the petrol and ethanol separate and the ethanol absorbs more water.  

As a result, the water can wreak havoc, and you may end up with a bike that won’t start until you drain the tank and refuel. 

Drain the bike of fuel to avoid any issues if your bike is sitting for a while. 

Doing so will also reduce the chance of the ethanol content damaging your fuel tank. 

E10 won’t be an issue for most modern motorcycles as there is an Oxygen sensor in the exhaust that communicates with the fuel injection to ensure the best combustion. 

However, it is best to avoid using E10 fuel if you have a fibreglass fuel tank, as ethanol can break down the composite and resins. 

Older motorbikes may suffer corrosion issues with gaskets and seals that were never intended to encounter ethanol. 

Key Takeaways

  • Motorcycles produced from 2011 onwards should be OK with the proper care taken
  • Older motorcycles are more at risk of damage to various parts of the engine and fuel system. 

How do I know if my bike can use E10? 

All motorcycles produced from 2011 will be compatible with E10 fuel. 

However, there are many circumstances where bikes before this will also be compatible without issue.

The best place to start is to check out the government vehicle checker.

You can also find a list of all compatible motorbikes here.

If you are still unsure, you should check your owner’s manual or contact your dealer; you could even check directly with your manufacturer. 

What if my bike can’t run E10?

E5 Super Unleaded will remain available on petrol forecourts, so if your motorbike cannot run E10, or if you have any doubts, you can still fill up with E5 fuel. 

Also, don’t worry if you use E10 by accident, as any potential issues will take time to materialise; just make sure you top up with E5 the next time you fuel up, and it will flush the system out.

The same goes if there is no E5 available when you go to fill up, it is thought that running a tank of E10 will not have any short-term problems providing you don’t leave it in the tank for a long time. 

Can I leave E10 in my tank while my bike is stored?

It is best to drain your bike of fuel before storing it for the winter

E10 fuel is affected by ‘Phase Separation’, which can take as little as 3 months. 

The ethanol separates from the petrol, which is still absorbing water. As a result, the fuel is useless when you start the bike again. 

Draining the fuel before storage will also reduce any risk of the ethanol causing unwanted corrosion damage. 

However, this is recommended regardless of whether you use E5 or E10 fuel. 

Will it affect MPG and will my bike lose power?

The AA states

“Using E10 petrol can slightly reduce fuel economy… There may be a reduction of 1%, which may not be noticeable in everyday driving and equates to no more than half a tankful per year for the average driver.”

While some studies showed that vehicles would need more fuel to get the same performance, overall, the consensus, especially for motorcycles, will be pretty nominal. 

It is unlikely that the everyday rider will notice much or any difference in their MPG. 

As for losing power, this is not an issue riders will face. 

Ethanol has a higher octane content than pure petrol, so it burns cleaner and leads to lower temperatures in the combustion chamber. 

There should be no reason for your bike to lose any power at all; perhaps it will run a little smoother.