breakdown e10


In the UK most petrol stations offer E5 fuel, which is petrol (derived from crude oil) with up to a 5% mix of bio-ethanol (derived from crops).


Currently, there are plans afoot to raise the ethanol content of UK petrol to 10% (E10 fuel) in a supposedly environmentally-friendly move designed to reduce carbon emissions. Countries like France and Belgium already offer E10 fuel at the pumps, and petrol stations in the United States have been selling high ethanol content fuel for years.


Media channels are referring to these proposals as a ‘no-brainer’, but are they really of advantage to scooter riders or even the general public? Sticky delves into this murky subject.


“I remember when all this was concrete”
“I remember when all this was concrete”


What is Ethanol?


Essentially it is an alcohol, produced in the ancient way by allowing yeast to act on sugars within crops. As you know from flaming sambuccas, alcohol is combustible and can therefore be used as a fuel.


Bio-ethanol fuel is made from commercially-grown crops such as sugar beet and wheat.


As you can imagine, there is an innate attraction to a fuel that you can ‘grow’ in a field, compared to one that has to be extracted from under the earth or seabed, often in a warzone.


Those who ride on the continent will already have encountered E10 at the pumps.
Those who ride on the continent will already have encountered E10 at the pumps.


What is bad about ethanol in fuel?


Actually, quite a lot; especially for 2-stroke engines.


  1. Ethanol is a detergent. It acts to strip oil from surfaces, harming the lubricating properties of 2-stroke oil on the moving parts of an engine.
  2. Ethanol attacks certain materials. Nitrile rubbers that were used in older vehicles for oil-seals, fuel lines, petrol tap and cap gaskets etc are all adversely affected by Ethanol. For this reason most engine builders now recommend the use of Viton oilseals in an engine. Ethanol also attacks some sorts of fibreglass resin and many of the older types of sealer used to line rusty fuel tanks. An increase in ethanol content is likely to increase problems with these parts in older vehicles.
  3. Ethanol is hygroscopic. This means that Ethanol fuels absorb water from the moisture in the air if not held in a sealed container. Putting water into an engine is not a really great idea because it promotes rust on con-rods and bearing surfaces. Water transferred to the float-bowl of a carburettor can cause massive running problems.
  4. Ethanol is energy inefficient. Compared to the same volume of premium petrol, Ethanol yields about 33% less energy. This means that fuel economy (miles per gallon) gets progressively worse the greater concentration of Ethanol is in the fuel.
  5. Ethanol fuel may require engine recalibration. The low calorific value of Ethanol may require adjustment to the fuel-air mixture for the engine to maintain efficiency. Fuel-injected engines built after year 2000 ‘should’ be able to adjust their fuelling dynamically to be able to cope with running on fuel with an ethanol content of up to 10%. Older engines, particularly air-cooled with carburettors, may need to be manually adjusted (made richer by upjetting) when changing to higher ethanol fuels.


VIDEO | Removing ethanol from petrol


Will Ethanol make my engine run hotter?


I’ve read claims of US studies which discovered that using higher concentrations of Ethanol in fuel raised the operating temperature of 2-stroke engines, but I’ve not been able to track these papers down. If true, this result could be explained by several factors:


    • Increased friction due to reduced lubrication effectiveness.
    • Reduced energy available from ethanol meaning that an engine has to be worked harder to achieve the same performance.
    • In air-cooled engines where fuel evaporation is used to help cool the engine, a richer mixture of ethanol-rich fuel is required to maintain a similar cooling effect.


Does higher Ethanol content have any good effects on an engine?


Ethanol is actually higher octane-rating than petrol. This means that it is  more resistant to engine ‘knock’ than straight petrol. Effectively Ethanol content can be used as an additive to reduce the risk of ‘knock’ or ‘pinking’ where previously other additives (MTBE and before that TEL tetra-ethyl-lead) were used to perform the same job.


There are videos online which show how you can use water to remove the ethanol content from petrol, specifically for old 2-strokes. Sadly this laborious process can’t be advised because it will reduce the octane rating of the remaining petrol. Unless you add octane booster afterwards then you are still risking running on a fuel that will damage your engine.



So if E10 is bad for my engine, what can I do about it?


The first thing to do is not to panic. People on the continent where E10 is far more common continue to ride old scooters and use 2-stroke engines, so the motors can cope when they are set up correctly.


If E10 does become regularly available in the UK we’d advise the following:


  1. Change all your fuel lines for Ethanol-resistant alternatives.
  2. Run a good quality 2-stroke oil with excellent lubricity.
  3. Pay attention if your fuel tap feels stiff to turn. This may be due to the Nitrile washer used in the tap swelling and getting stiff. If this happens the washer can start to break up and the tap will either leak or bits of the washer will find their way through to the carburettor. Viton sealing washers are now available for many old fuel taps.
  4. When rebuilding a motor ensure that all fuel-facing oilseals are Viton or another ethanol-resistant material.
  5. If you are using E10 all the time you may well need to upjet your carburettor slightly.
  6. If you are using E10 all the time then you can in theory retard the ignition timing by a degree or so to cope with the faster burn of E10 fuels. [N.B. this section revised 5/3/20 as a result of reader feedback and checking studies such as this]
  7. E10 burns cooler and liberates less energy than E0 or E5 fuel so if you use an Exhaust Gas Temperature gauge (EGT) then you should expect to revise your expected temperatures. 
  8. If you aren’t using your scooter for any great length of time then seal the fuel tank breather so that ethanol can’t absorb any water. Want to see how quickly ethanol fuels can absorb water? Watch this video.


What the introduction of E10 will do is reduce the margin of error for setting up tuned engines. An engine that is on the absolute edge of safely for jetting, ignition timing and cooling on E5 fuel might be tipped over the edge into meltdown or seizure if you fill it with E10.


The solution then will be to increase the margin of safety in respect to your fuelling and lubrication by upjetting and maybe running a slightly richer oil mixture, particularly if you are doing any long-distance work where you’d expect your engine to get hot.


In Spain - E10 fuel and Millers VsPE 3-in1 Ethanol protector. Incidentally, Iggy blew his Quattrini up in the UK whilst using this fuel additive...
In Spain – E10 fuel and Millers VsPE 3-in1 Ethanol protector. Incidentally, Iggy blew his Quattrini up in the UK whilst using this fuel additive…


Are anti-ethanol fuel additives any good?


There are dedicated fuel additives – sometimes called stabilisers – that are supposed to counter the effects of Ethanol-rich fuels, however without a degree in Chemistry and months of study in a lab – then it is impossible to know if these additives actually work.


I’ve been involved in the motor trade long enough to be very cynical of any miracle formulas. History teaches us that you can tell people pretty much anything and if they want to believe it works then they’ll spend good money on snake oil, based on bad science.


As an example of bad science, I myself produce a fluid that both wards off vampires and combats the signs of ageing when applied to directly a woman’s face. None of my former girlfriends have died from vampire bites so it has a 100% success rate. Side effects of misuse include pregnancy.


People who use fuel stabilisers might tell you that they 100% work because their engines haven’t blown up. Equally, it could be that their engines wouldn’t have blown up without the additives. This is another example of bad science.


I don’t have enough knowledge to say whether substances like the Millers Oils fuel stabiliser Iggy was using when his Quattrini M210 melted a crank on the way back from Exmouth last year actually work or not but he was advised to stop using it by Chiselspeed.


There are plenty of different additives on the market. The material safety data sheet for Lucas Safeguard Stabiliser shows the main ingredient is up to 80% ‘hydrotreated heavy naphtha’ (petroleum), which is a product derived from crude oil.


Imagine this; if you add more neat petrol (or naphtha) to petrol/ethanol mix, what you are actually doing is reducing the percentage ethanol content in the tank a little bit. It’s certainly not doing any harm but equally it’s impossible to know if any of the other ingredients are doing any significant good either.


So for me, the jury’s still out.



E10 – High Ethanol content fuel – will it kill my scooter? | OPINION


If Ethanol in fuel is so harmful to engines, why is it being promoted as a good thing?


Organisations like Extinction Rebellion have governments in a flap. Most people agree that the climate is changing but not every scientist agrees about why. Carbon dioxide gas emissions are one of the factors getting the blame for the greenhouse effect, so the current buzzword is ‘carbon reduction’.


As a politician this is an ideal time to release a knee-jerk sticking plaster remedy that looks like it might have some environmental benefit, until you actually study it closely. This is where you have to drill down into the news to find out who benefits financially, because the world still remains a money-go-round.


The headline on the news was that increasing Ethanol content from 5% to 10% was going to cut UK carbon exhaust emissions by as much as 6%, but that doesn’t actually make any sense.


Ethanol contains carbon atoms and when you burn it those carbon atoms still combine with oxygen to make carbon monoxide and carbon dioxide as by-products. I’d be surprised if adding this shit to petrol would have a significant impact on carbon emissions from exhausts, but it certainly will not achieve a 6% reduction. 


So if burning Ethanol still releases carbon dioxide, how is it helping?


Ah, this is where we enter the realms of more bad science with the absolute bullshit concept of ‘carbon offsetting’.


The claimed net reduction in carbon emissions actually comes from the process of growing the wheat or sugar-beet because the plants absorb carbon dioxide from the atmosphere as they grow. This is supposedly ‘renewable’, because the carbon dioxide emitted from the exhaust is captured by the plants.


Apparently it’s all ok, because one offsets the other.


That’s fine until you start to think about this for a moment. If that wheat wasn’t grown to make crappy fuel for petrol engines, what would be in the field in its place? Well, you could grow wheat and feed it to humans unless world famine was solved while I was sleeping.


Even if you didn’t sow wheat, something would grow there – that field wouldn’t be a desert. Those plants would still be absorbing carbon like they have for millions of years before they knew that they were also doing the important job of ‘carbon offsetting’.


Carbon offsetting is a load of unadulterated bullshit aimed at making you feel less bad about polluting.


We all pollute; even the people from Extinction Rebellion.


So who profits?


This is where we get to the interesting bit. Companies running farms and refineries based mostly in the north of England took a gamble on the future demand for bioethanol. It’s an industry already worth £1BN in the UK.


Sadly the demand for ethanol from the petrol companies has not been as high as expected so the industry is not as profitable as anticipated.


Thankfully we have the All-Party Parliamentary Group for British Bioethanol to protect us. They are basically a cross-party bunch of MPS from the constituencies in Scotland and the North East; where the farms and refineries are located. Coincidence I’m sure. They are supported by an expensive-looking PR company called Finn Communications; no doubt paid for by the Bio-ethanol industry’s lobbying war-chest.


Obviously if the fuel specification for the UK went from 5% ethanol to 10% then ethanol demand would increase massively, these businesses would do well and the MPs of those areas would be able to stand tall knowing that they’ve contributed to saving the planet.


Only they haven’t.


They will have introduced a fuel that some sources estimate will result in 880,000 incompatible cars going on the scrap heap. Think of all the energy, resources and pollution required to replace almost a million vehicles?


Is forcing people to buy new when they were satisfied with old really environmentally friendly, or is it just feeding the consumerist beast?


Isn’t keeping old vehicles on the road a form of recycling?




Final word


Basically after the diesel fiasco it’s as clear as vodka that politicians can’t be trusted to make the right call on anything environmental.


They thought they were doing the right thing by promoting diesel due to the lower carbon emissions, only to later discover the harm resulting from their increased nitrogen oxide emissions.


The whole thing is a farce. My suspicion is that they will believe whatever the lobbying groups tell them at expensive parties.


Now the solution is to introduce more ethanol to fuel, crippling part of the current vehicle fleet, reducing the fuel economy of most engines, and still pumping out roughly the same levels of carbon. And all of this is supposed to be of great benefit the environment?


If you believe that then maybe I could interest your wife/girlfriend/daughter in an anti-vampire service that I offer. As a favour, I’ll do the first treatment free of charge…


Words: Sticky

Images: Iggy

Intro Image: From Vince (Olympic SC) as featured in Sticky’s book Scooterboys – The Lost Tribe which is available here.



SLUK Shop – products made for polluting vehicles, no food crops harmed during their production

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