UK E10 Fuel

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With the recent shortage of petrol , especially in the East of England, I filled up 10 days ago on E10. It was fine at first. I did 50 miles a couple of days later. Today, I did another 60 miles and throughout, the bike was a little hesitant, particularly on tickover and a constant throttle. It stalled at traffic lights when I gave it a small amount of throttle.

On the way home I filled up with E5, about 2 gals, just under half a tank. The bike was immediately transformed and happy again.

E5 is a higher octane fuel. 10 days seems a bit soon for E10 to go off. Possibly, the E10 I had was contaminated. Pumps in the UK have been running dry, so maybe I got the dregs? Thought I'd share the experience. Will have to take it out again tomorrow, just to be sure... :D
 
It’s not only about which type of petrol, but which brand.
Years ago I filled up my T140 on the way back from Cornwall in some small village at a no brand station.
I thought the bike was f*cked it ran so rough. But at the next fill up, normal service was resumed.
And I know of similar stories from super market petrol stations.
So not only do I always put Super Unleaded in my bikes, I also stick with known big brands.
My local Shell garage now only sells ‘Welcome Break’ fuel (its a Welcome Break services). Which essentially means they’re selling whatever they could buy that was the cheapest at the time. I don’t buy from them anymore.
 
With the recent shortage of petrol , especially in the East of England, I filled up 10 days ago on E10. It was fine at first. I did 50 miles a couple of days later. Today, I did another 60 miles and throughout, the bike was a little hesitant, particularly on tickover and a constant throttle. It stalled at traffic lights when I gave it a small amount of throttle.

On the way home I filled up with E5, about 2 gals, just under half a tank. The bike was immediately transformed and happy again.

E5 is a higher octane fuel. 10 days seems a bit soon for E10 to go off. Possibly, the E10 I had was contaminated. Pumps in the UK have been running dry, so maybe I got the dregs? Thought I'd share the experience. Will have to take it out again tomorrow, just to be sure... :D
Last night I was out on my BSA A10 and had to fill up with E10 and I've been wondering what to expect
Nothing so far but I've only done 25 miles
A mate has been running his British built 350 bullet on E10 he says it's making the bike a bit lean, taking a long time to warm up
 
Not sure what the news is telling us now (too much work and no TV!), but I filled up at a Shell station yesterday that was diesel only... So somebody got the dregs of the tank there before the petrol ran dry :-(
 
"E5 is a higher octane fuel."

I would have thought that, all else being equal, E10 would be higher octane than E5 since there is more alcohol. But I misunderstand the whole process...
 
Mine likes esso super or the shell v power (super) didn’t like e10 when I had nothing else took ages to get going and drank more
 
You may need to turn your air screws in a little. In some Triumph workshop manuals they say how much to increase jet sizes per percentage of alcohol so it was well known long before the "E" gas.

AFAIK: Ethanol does have a higher octane rating that gasoline. E gas is usually lower octane rated gas + Ethanol which raises the octane rating to what the pump says. So E10 Premium should equal Unleaded Premium in octane rating.
 
"E5 is a higher octane fuel."

I would have thought that, all else being equal, E10 would be higher octane than E5 since there is more alcohol. But I misunderstand the whole process...
In the UK we seem to have associated lower ethanol content with 'premium', so it gets a higher octane blend and a 20% price hike.
 
But octane really should not matter on stock lower compression motors. Octane is meant to inhibit pre-ignition, ping or pinking. This happens in higher compression engines like most modern cars and bikes. These nearly all have knock sensors to tell the ignition ECU to retard timing on the fly. That's why you can lower rated fuel in modern cars despite the guidance from the manufacturer. Our classic bikes will not experience pre-ignition with lower octane unless somethig else it not right.
 
But octane really should not matter on stock lower compression motors. Octane is meant to inhibit pre-ignition, ping or pinking. This happens in higher compression engines like most modern cars and bikes. These nearly all have knock sensors to tell the ignition ECU to retard timing on the fly. That's why you can lower rated fuel in modern cars despite the guidance from the manufacturer. Our classic bikes will not experience pre-ignition with lower octane unless somethig else it not right.
It’s not quite that simple.
First the lower octane over here is the high ethanol stuff. The ‘super unleaded’ has little or no ethanol.
Second the lower octane stuff, which has more ethanol, will degrade faster, so you might well have lower than you think especially if it sits in the tank for a while between rides.
Whereas the higher octane stuff, even if it degrades at the same rate, would still be higher, but as it’s low / no ethanol it’ll degrade slower. So you’re certain to have a higher octane if sat a couple of weeks.

With regards to modern cars and bikes, yes you can run on lower than the recommended octane BUT you should know you’re throwing away power as the ECU adjusts to prevent knock.
On some point engines, like big V8 AMG Mercedes lumps in his can be a LOT of power. It’ll probably do less mileage too.
 
It’s not quite that simple.
First the lower octane over here is the high ethanol stuff. The ‘super unleaded’ has little or no ethanol.
Second the lower octane stuff, which has more ethanol, will degrade faster, so you might well have lower than you think especially if it sits in the tank for a while between rides.
Whereas the higher octane stuff, even if it degrades at the same rate, would still be higher, but as it’s low / no ethanol it’ll degrade slower. So you’re certain to have a higher octane if sat a couple of weeks.

With regards to modern cars and bikes, yes you can run on lower than the recommended octane BUT you should know you’re throwing away power as the ECU adjusts to prevent knock.
On some point engines, like big V8 AMG Mercedes lumps in his can be a LOT of power. It’ll probably do less mileage too.
I get that, but my point is not to fuss over octane rating for our older machines....ethanol has its own issues for our bikes (rubber , water absorption/corrosion and composite fuel tanks etc.).
 
I guess it could...didn't they de-tune/drop the CR on all the combats after initial issues?
Nope. My buddy's 72 combat interstate will ping badly on anything less than 93 octane (US).
 
Pure Ethanol has an Octane rating of 113

However Ethanol being CH3CH2OH contains inherent oxygen thus changes the stoichiometric ratio
which needs to be allowed for in a formulation change of the complete petrol

Just stripping out Ethanol is not as easy as it seems
 
Pure Ethanol has an Octane rating of 113

However Ethanol being CH3CH2OH contains inherent oxygen thus changes the stoichiometric ratio
which needs to be allowed for in a formulation change of the complete petrol

Just stripping out Ethanol is not as easy as it seems
Yup, strip the ethanol out of E10 in the U.K. and you‘re probably left with expensive paraffin !
 
On my 4th interstate tankfull of E10 since the petrol shortage and no issues, in fact, I quite like as it lost a little vibration. The only noticeable difference is when the throttle is cracked open, not quite the get up and go response, but in the rush hour on the A34 and M3 around here that is not great loss.
 
I've never had a problem. I usually fill at the same station - super premium E-10 although it doesn't need it. A two gallon purchase doesn't break the bank.

A little clarification: I see pre ignition used where it should be detonation. Pre ignition is when fuel/air charge is lit by something other than the spark plug before the timed spark, a hot spot such as a glowing piece of carbon. Detonation is when the charge is lit by the spark but the flame front progresses too fast becoming sort of an explosion - detonation, thus the pinging.

I've heard all sorts of complaints about E-10 in all sorts of applications but never experienced any except small engines where the rubber in fuel pumps succumbed to the alcohol. My FIL's '56 Ford fuel pump didn't like it either but replacement was made with tolerant diaphragm. No such rubber parts in a Norton.
 
On my 4th interstate tankfull of E10 since the petrol shortage and no issues, in fact, I quite like as it lost a little vibration. The only noticeable difference is when the throttle is cracked open, not quite the get up and go response, but in the rush hour on the A34 and M3 around here that is not great loss.

God I dread travelling on the A34 !
 
On my 4th interstate tankfull of E10 since the petrol shortage and no issues, in fact, I quite like as it lost a little vibration. The only noticeable difference is when the throttle is cracked open, not quite the get up and go response, but in the rush hour on the A34 and M3 around here that is not great loss.
It is often said that much less than 5bhp is difficult or impossible for ‘normal’ riders to feel.

If that’s true, that means you could be down by that margin with E10 in your bike.

I fully agree that for many this isn’t an issue. But trust me, for many others, it bloody well is !
 
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