E10 Fuel Issues

So with the switch to E10 fuel back in September I tried it before jumping on the buy super unleaded bandwagon everyone at work seems to be doing.

My car is a 63 plate but high mileage and 3 cylinder so it’s not smooth at the best of times.

I’ve lost 15MPG doing the same driving and it sounds like a tractor and coughs with idle. Filled the tank with Esso Super Unleaded which is ethanol free in some parts of the country and 100 miles later when the ECU had time to adjust its back to normal and normal MPG.

Anyone else had these issues.


It’s not just you.

I’ve been sticking to super unleaded myself. If E10 is the only option, I’ve driven off and looked for another petrol station to try instead.


Most will lose up to 5mpg on avg. 15mpg really sucks :grimacing:

It was sold as cleaning up the environment.

If they had also explained to motorists that the changes would cost them more to fill up then there would be uproar.

I think it’s the double whammy of swapping to a less efficient fuel plus the 140-145p liter that’s hitting people who drive a lot.

We’ll find in five years time reports of excess carbon build up knackering engines.


it’s probally going to hurt single grade petrol stations the most as theres a big uptick in demand for super unleaded.

The extra price is paid for by the better MPG and the engine not sounding like a tractor and not coughing on idle.

Other countries in Europe have been using E10 for quite a while now and I haven’t heard of ruined engines because of it. It’s less efficient, yes, but there is no need for scaremongering like there was with unleaded

Not something I’ve experienced during the 1000-odd miles I’ve driven with E10

I’ve heard in Finland from friends their regular has basicly become Super Unleaded since they brought in E10 95 with most stations only selling super.

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Most likley going to depend on the car, smaller engines with high mileage seem to be the worst. (100k miles plus) It’s like 7p extra round here for super so not much.

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Those countries are also running FFVs so the cars are built to take it. Our cars in the UK were never built to take it.

They also specifically build vehicles that can take higher amounts with this badge.



What car is it? My 2015 Auris seems fine. It’s dealer maintained, so it’s possible they’ve made some adjustments, but I haven’t done enough mileage to notice any mpg changes.

Mpg is dependent on many factors, though. Tyre pressures, air temperature etc, so there’s always some variation. A 15mpg reduction seems a lot, though.

Aren’t Flexible Fuel Vehicles those which are designed for taking a much higher E-level than anything we have at the pumps at the moment? In fact the picture you’ve just added says ‘E85’ on it, which is a massively different concentration from E10.


Yeah so in places in Europe that have been using higher amounts they purposely build their engines and tubes etc to take it. So the Volvo you buy in the UK is different from the one in Sweden.

That E85 is what you’ll see in Europe at pumps for specifically Flex-Fuel vehicles.

Brazil that take it even further so they can be entirely run on it (E100). Again these have completely different parts than the same vehicles sold around the world. Things like the rubber tubes which would get destroyed by high percentage of ethanol.

So going back to Europe and E10 they have a completely different bunch of cars on the road.
So you can’t say because they haven’t had issues that our UK will be fine. Our modern cars should* be fine.

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2013 Polo with in excess of 100k miles, self maintained oil changed yearly and sparkplugs only 6k miles old.


:thinking: Well it should be fine. :man_shrugging:

The only issue with E10 are the first gen FSI engines that VWs had.

But they had carbon coking issues back in the day :sweat_smile:

I’m using super unleaded 15MPG is alot and it coughs on idle on E10 when it never did before or about 50 miles after switching to super unleaded.

I have a 2011 Fiesta (110k+ miles).

Can’t say I have noticed any difference yet.

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Is there an owner’s club forum you could take a look at? It sounds like an ECU or sensor issue that might be preventing your car from adjusting its performance to the fuel mix.

Mine seems to be just fine on E10 at the moment, but this has reminded me that I want to use my Monzo Google Sheets export to move my fuel economy tracking out of Fuelly.

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