Topic: E10 Petrol

pargeandmarge    -- Aug-2-2021 @ 2:38 PM
  Hi All
A technical question will we be able to run E10 petrol in a dingy outboard or should we use super unleaded?

Will it affect others with inboard or outboard petrol engines or is it down to year of manufacture?

Marge and Parge

Paladine    -- Aug-2-2021 @ 3:00 PM
There is a lot of information here

I would think that, as it's being recommended NOT to use E10 in petrol-driven lawn mowers and generators, owners of smaller o/b motors should think carefully and, perhaps, contact the manufacturer. Also owners of older petrol-powered boats, such as Freemans, would be advised to use the higher grade of petrol.

Without getting political, I also think it's a load of b*ll*cks. What might be saved by such a move (including diesel) in terms of pollutants being emitted comes to nothing while the major pollutors, such as USA, China, India, continue to belch out pollutants in staggering quantities. The view from the moral high ground might be good, but it don't mean a lot in real terms!

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This message was edited by Paladine on Aug-2-21 @ 4:11 PM

Paladine    -- Aug-2-2021 @ 3:10 PM
I have also read this: "The DfT has suggested that E5 fuel might only be available for five years - potentially removed from pumps in September 2026.

After this date, the regulation will be reviewed to decide whether E5 should be retained or if it will fall on owners to turn to specially-created fuel additives for their older machines."

So, if you've got an older petrol engine in your boat, you may have to consider having a diesel engine (or newer petrol engine) installed, or changing your boat before the market catches on.

Been hit by another boat? Report the incident to the Marine Accident Investigation Branch’s dedicated accident reporting line on 023 8023 2527 which is monitored 24 hours a day.  Help to make the Broads safer.

Loughrigg    -- Aug-2-2021 @ 5:43 PM
  Where to start,

Almost all modern outboards will at least tolerate E10, and i think tolerate is the optimal word here. The outboard industry has made concerned noises about the potential damage to fuel systems, and especially for the safety of boat owners.

The real cause of damage to marine engines is dissolved fuel system components being deposited inside sensitive modern engines.

The risks for boat owners come from three key characteristics of ethanol.
* It’s a (very) powerful solvent,
* It doesn’t stay mixed with petrol, and
* It has a very short shelf life.

The solvent nature means that it dissolves some of the components of fibreglass fuel tanks, as well as many elastomer (rubber like) materials found in fuel systems. These pass through the best filters and end up forming destructive deposits inside marine engines.

Basically, the Ethanol component will dissolve dirt and residues in your fuel system you didn't even know you had.

The chemical attack on tanks and hoses mean the inevitable leaks are a fire risk. That means a fire risk, or at best, a powerful solvent attack to the bilge surfaces. And for inboard petrol, if those surfaces are GRP - it'll attack those as well.

Ethanol and petrol will 'separate' under normal, moist boating conditions, and that action concentrates the ethanol, so it can do even more damage.

Ethanol has higher volatility than most elements of petrol, meaning it evaporates off first. That means it may go ‘sour’ in as little as 2 weeks.

Ethanol is hygroscopic and absorbs moisture (approx 10 times the level E5) just like brake fluid and diesel fuel. Up to 0.5% absorption is not a problem, but beyond that, the saturated ethanol sinks to the bottom of the tank in a process called Phase Separation. I've attached a pic (courtesy of Mercury Marine). The saturated ethanol is at the bottom.

No amount of stirring or shaking will mix the ethanol back with the petrol, and there are no proven additives that will fix the problem. So that leaves us with some undesirable side effects.

There are some expensive fuel additives on the market with vague claims about helping the situation but none even claim to be able to stop phase separation before it commences.

After phase separation, 100% petrol is floating at the top of the tank. That sounds great until you realize that the missing ethanol was the all important octane booster.

So the first sign of separated fuel may be pre-ignition or pinging as the octane in the remaining fuel drops about 3 points.

As the phase-separated ethanol builds up at the bottom of the tank, it eventually reaches the fuel pick-up tube. At this moment, we get a 100% dose of water saturated ethanol through a fuel system and engine designed to cope with no more than 10%.

In nearly pure form you'll be surprised how strong a solvent ethanol can be. The result is some real damage to engines and fittings, and a high risk of fuel leaks. The moisture that causes separation will always collect in fuel tanks (with breather pipes) particularly in hot summer weather when the temperature differential is highest. Humid air is drawn in through the tank breather and as the days cools into evening and night, condenses on the walls of the tank, runs down the walls, and is immediately attracted to the ethanol.

Bingo - Phase Seperation and imminent damage to systems.

While, the claim that most 'modern' engines will cope that's only if all your associated components parts are Ethanol resistant. That's an expensive way to run your engine assuming you can even find the necessary resistant parts.

My advice (and the advice i'm taking for myself) - is avoid, avoid avoid. Change over to E5 Super if you can't find E5 standard.

Oh and btw - if your into the Green agenda or just care even alittle about our flora and fauna, in America and Australia, tests have shown that the inefficient burning of Ethanol in both old AND new engine has ended up with large concentrations of Ethanol being deposited into waters - poor old fishes. This then seperates into a layer that gets sucked into engine raw water systems and attacks the component rubber parts and fittings.

Karen has intimated that this might be the opportune time to change to a rag n stick - never i say, NEVER!!!:eg:


'Who says you can't get 43 boats on Ranworth Island'
'Ubique Loquimur' - We Speak Everywhere!

This message was edited by Loughrigg on Aug-2-21 @ 6:52 PM

Loughrigg    -- Aug-2-2021 @ 5:55 PM
  Sorry couldn't add the photo to my post so here it is.


'Who says you can't get 43 boats on Ranworth Island'
'Ubique Loquimur' - We Speak Everywhere!

pargeandmarge    -- Aug-2-2021 @ 7:43 PM
  Thanks both for really thorough answers my mind is made up.
kindest Regards
Marge and Parge
P.S tell Karen to mind the quant on the underside of a bridge as it may jar her arms. Tinhat

Paladine    -- Aug-3-2021 @ 7:12 AM
Loughrigg wrote, ”My advice (and the advice i'm taking for myself) - is avoid, avoid avoid. Change over to E5 Super if you can't find E5 standard.”

This is a very serious matter and, having done some more research, including looking at what manufacturers are saying, I totally agree with that sentiment. Not just for boat engines and gardening equipment either. Mrs P’s little petrol-engined car only does about 2,000 miles a year, and that was pre-Covid. With a shelf-life of around 2 weeks from leaving the refinery, this new fuel simply won’t cope with sitting in the fuel tank for weeks on end.

Been hit by another boat? Report the incident to the Marine Accident Investigation Branch’s dedicated accident reporting line on 023 8023 2527 which is monitored 24 hours a day.  Help to make the Broads safer.

Dykedweller    -- Aug-3-2021 @ 8:55 AM
  I had a new  McCulloch hedge trimmer which was working fine, when I went to use it the next time it wouldn’t start. Further investigation revealed that the black rubber fuel pipe within the fuel tank was now just a piece of black jelly. Even after replacing this it never performed as well again presumably because of of particles still floating about
in the carburettor. I now use premium petrol in all of my garden implements and the time has probably come to change to premium in our low mileage cars.

FreemanBattyBat    -- Aug-3-2021 @ 11:08 AM
  A similar story of doom was rife when E5 came on the scene. Owning a Freeman with a petrol engine ( early crossflow Escort type) myself and most owners in a similar situation were concerned. It transpired the awful predictions were overstated as most marine version engines of this type run cool and at 2000rpm maximum most of the time the effects seem minimal.
However with the change to E10 owners are being advised to change to Super unleaded ( Esso claim theirs contain 0% ethanol but regulations insist they label it E5) The only hope is that 0% super unleaded will remain available despite Mr P's information it won't be after a certain date.

I also agree the fact that our small island will make no concernable difference whilst others pollute willy nilly.

Freeman F23 Flittermouse moored near

annville    -- Aug-3-2021 @ 12:56 PM
  Hi Thats as maybe who were the biggest polluters in Victorian times with the industrial revolution? Sin's of the Fathers comes to mind. why should just the rest of the world pay more, we must all do our bit. John

Dilligaf    -- Aug-3-2021 @ 2:04 PM
  For only ocaisionaly used garden equipment it's worth considering something like aspen instead of regular petrol, maybe even for the last carbfull of the season in an outboard too as it has a 5 year shelf life once opened, I always had trouble with my chainsaw till I switched over and been fine since.
It's expensive but I use a 5 litre tub in 5 years so worth the lack of aggro, I've put a splash in a bike tank as well before laying it up for any extended period, saves all the carb stripping as there's no gumming up to worry about.  

Formerly 'LeoMagill'

Karen&Mike    -- Aug-3-2021 @ 2:12 PM
  I think the issue is that the rest of the world collectively isn't doing its bit though, is it ?

And some of the things being done both here and abroad are lauded as greener when sometimes they are not.

There are many schemes for example, to encourage planting of trees, but nothing to fully and properly protect all the trees (and shrubs and gardens etc) that we already have. I firmly believe that a great step forward would be to say no tree anywhere can simply be felled, ripped out etc. ALL trees should automatically be protected, be it along the side of railways for example  ( yes thats another story isn't it) or in private gardens.

Anyway, back to E10 - which is not all it's cracked up to be, causes damage and the need to produce other replacement components or even full replacement items  ( all this at a cost to the environment ) .

Are you giving up,your Diesel engined boat then Annville , to pay for the sins of your fathers ? Sorry couldn't resist asking,


"Wind up the elastic band Karen - we're setting off!!"

This message was edited by Karen&Mike on Aug-3-21 @ 3:16 PM

FreemanBattyBat    -- Aug-3-2021 @ 2:40 PM
  Main topic was about E fuel not pollution.
I was just passing a comment on a previous post re pollution.....
Sins of our fathers I'm not denying, but (and it's a big but) I still stand by my statement that our present output changes little in the wider context.

Freeman F23 Flittermouse moored near

This message was edited by FreemanBattyBat on Aug-3-21 @ 3:42 PM

Loughrigg    -- Aug-3-2021 @ 4:02 PM
A similar story of doom was rife when E5 came on the scene. . It transpired the awful predictions were overstated

I'm not foretelling a story of doom. Not at all. E10 has been around for a while in the States and Australia. However, it was introduced with quite a bit of fanfare and industry backing.
What's happening in the UK seems to be - "while we sleep" - if i can get away with that phrase.

I also wanted to clear up my previous post just a bit because I think it does skim over a few salient points.

So here we go and i ask forgiveness of anyone who is already bored solid by the subject Smile

Ethanol has been in our fuel for a long time. Up to 5% - that's what E5 means. It's not new and water absorption is not new.

Ethanol (ethyl alcohol) normally (i'm stressing normally) blends seamlessly with petrol and it's pretty difficult to separate them.

Unless you add too much water to the mixture. And that's the rub!!!

E5 fuel will already hold up to 2.500 ppm water - E10, 7000 ppm. [at 70 degrees] - and that's from the refinery. forget what it'll pick up at the filling station tanks.

Let's break it down. Ethanol itself, as i stated previously is highly hygroscopic, both absorbing water and enabling whatever it's blended into to absorb more water. Some have described this phenomenon as "ethanol attracts and absorbs water from whatever is around it".  That's more of a "lay person" way of describing what happens. Ethanol doesn't "reach out and grab" water from the air, but it does make it easier for the water to be absorbed by the mixture.

So having said that, all ethanol blends have a certain tolerance or ability for absorbing water into the mixture.  Think of it like this;

At up to 5% (E5) the fuel mix is such that the ethanol present can and will absorb some water but struggles to have the strength to break the full absorption barrier and drop out of the fuel to the bottom of the tank fully saturated with water. It's pretty happy where it is - and it does just that, remaining mixed with the petrol in a loving embrace.

At 10% (E10) that barrier is much easier to attain and pass. The higher concentration of Ethanol simply gives up wanting to stay mixed with the petrol and is more interested in the water and separating out. At this concentration Ethanol loves water a lot more than it loves petrol - and is happy to run off with the water and separate from the fuel in a quick and acrimonious divorce.

The chemical reason for this is that the hydrogen bond (polar) between water and ethanol is stronger than the non-polar bond between petrol and ethanol.

If you were to pour 100ml of water into a litre (1000ml) of E10 - 130ml of Ethanol and water will immediately separate out - that's a full 30ml of Ethanol or 3% (3 points) of Octane.

The point I'm trying to make (admittedly in a longwinded fashion) is this. Ethanol in fuel (specifically E10) is viable but not easily so. It takes special and advance engines, engineering, detection systems and a whole lot more to successfully implement. Sadly, history shows that an ill-informed consumer base tend to be the guinea pig of choice in these sweeping changes and not always with the best information about the unintended consequences.

I personally am an earlier adopter of technology but not for technology's sake. The has to be reason and purpose behind the technology - otherwise what 's the point? The 'green' benefits are stated as the main reason for the introduction.

"The environmental agency ePURE says that displacing 10% of Europe’s petrol with ethanol through E10 fuel would reduce greenhouse gas emissions from petrol by more than 6%."

Sounds good doesn't - but there are drawbacks

The RAC says that E10 is potentially less efficient than the current E5 blend of fuel, which could mean it increases fuel bills for drivers, particularly those who own smaller cars. You'll use more fuel on the same journey which is a counter intuitive offset at best. Also, because E10 is produced from plants, there are concerns over deforestation, which risks creating its own CO2 impact.

When all said and done how much difference will it make - no one has really done the maths - sadly.

Swings and roundabouts folks - swings and roundabouts Smile


'Who says you can't get 43 boats on Ranworth Island'
'Ubique Loquimur' - We Speak Everywhere!

This message was edited by Loughrigg on Aug-3-21 @ 11:25 PM

annville    -- Aug-3-2021 @ 4:13 PM
  Hi Karen YES my next build will be electric with NiFe battery's all though i will still have gas cooking. John

Loughrigg    -- Aug-3-2021 @ 4:25 PM
  Hi John,

NiFe batteries?  - running what?


'Who says you can't get 43 boats on Ranworth Island'
'Ubique Loquimur' - We Speak Everywhere!

Karen&Mike    -- Aug-3-2021 @ 4:27 PM
  Do you build your own boats John ? Or have them commissioned ?

Another point not considered here is that of the waste and disposal of petrol, and diesel boats/engines. Cars do not last as long as boats so it really does seem such a waste to me that sweeping changes such as the E10 thing, and enforced withdrawal of alternatives , renders useful items as useless  Frown  We are a wasteful society  as it is! Sadly many of the so trumpeted greener options have just as much (sometimes worse) impact in their production or wider impacts. It's all a lot of lip service and game playing. And don't get me onto electric cars and how that's being implemented. We are simply destroying our world in different ways. It's lifestyles that need to change. Consumer demands need to change, especially re food and all the items we get that have travelled half the world over first !


"Wind up the elastic band Karen - we're setting off!!"

annville    -- Aug-3-2021 @ 5:34 PM
  Hi Karen I have the hull and woodwork built to my design windows from Sea Glaze i then do the rest apart from the RCD cert (too complected) John

annville    -- Aug-3-2021 @ 5:39 PM
  Hi Mike not sure what you meen ? (propulsion motor)John

Loughrigg    -- Aug-3-2021 @ 9:54 PM
  Hi John,

I hope you'll forgive me for saying but NiFe batteries for electric propulsion is not a good idea in my honest opinion. This chemistry is very very outdated. First commercialised in 1901 just 20 years or so after the lead acid battery was introduced.

They are very limited in their performance in comparison to newer chemistries.

Low specific energy of about 20Wh/kg which is very low compared to other lithium options which can exceed 150 Wh/kg. THe upshot being that you'll need a heck of a lot more space and weight capacity. Approximately 7 times the space and weight required by other chemistries.

Low cycle efficiency - NiFe boasts a discharge rate of about 65% meaning you have to put alot more energy in (about 1.5 times) to fill them up against what you can expect back.

High self discharge rates - so these batteries lose approximately 1% per day of stored charge. That's 30% per month. Not a problem if you're utilising them all the time but not great if you leave them for a while. Other lithium options have rates that vary between 2 & 5% and even this can be mitigated with a good BMS or balancing system in line with a tiny trickle charge.

Maintenance - just like flooded lead acid batteries NiFe will require electrolyte checks. The life of these batteries is supposedly huge - 50 years plus - but that assumes diligent maintenance.

Lastly - cost - the current UK retail rate for these batteries is around £440/kWH which is comparable to LiFePO4 for example. But whilst the cost is comparable the efficiency and other points above really knock that cost up massively.

I would go with Lithium Iron Phosphate (LiFePO4).

LiFePO4 batteries have overwhelming advantages;
Much lighter and easier to handle.
Much more efficient - charge/discharge efficiency is over 90%.
The have low self discharge.
They are low maintenance - no electrolytes to check.
They have simpler charge requirements - ie - you don't have to have get into equalisation charging although you will need a BMS (battery management system) to ensure overcharging and cutoff are managed so as to not cause damage.
There is almost no Peukert effect. That is to say you can discharge them at very high rates without loss of capacity.

While NiFe do have some good points - they are used extensively in large scale solar projects due to the huge charge rate they can accept - there are much better options for smaller installations.

If asked I wouldn't recommend them for a boat installation.



'Who says you can't get 43 boats on Ranworth Island'
'Ubique Loquimur' - We Speak Everywhere!

This message was edited by Loughrigg on Aug-3-21 @ 11:26 PM

annville    -- Aug-4-2021 @ 9:39 AM
  Thanks for that, Mike size and weight are not a issue along with a auto top up kite, cost per cycle is the big advantage along with longevity, BUT things do change quite rapidly so not craved in stone, have to sell this one first. John

Marshman    -- Aug-5-2021 @ 9:02 AM
  Aspen petrol is not specially easy to find but Stihl do exactly the same stuff, and often cheaper.

The 2 stroke is premixed and burns much cleaner - you are not followed around by a blue haze and and you get much easier starting and you get the benefit of longer storage. It is virtually benzene free and does not give off anything like the pollutants that ordinary petrol give. All in all  a better alternative - but more expensive naturally!!!

Paladine    -- Aug-5-2021 @ 12:04 PM
Both the Aspen and Stihl websites have a 'dealer finder' facility, so neither product is difficult to find. The price difference is a couple of quid per 5 litres, so it really boils down to which dealer is the nearest. Any saving one over the other can easily be lost by having to travel further to get it  Confused

Been hit by another boat? Report the incident to the Marine Accident Investigation Branch’s dedicated accident reporting line on 023 8023 2527 which is monitored 24 hours a day.  Help to make the Broads safer.

Chicol    -- Aug-22-2021 @ 10:06 AM
  I found this threat very interesting, and for the last couple of weeks I've been looking at garage offerings, so thought I'd drop some thoughts, as some of the very good and techical response are long to read, and I think I missed some points.

I thought e10 was only now in standard 95 octane and e5 in higher octane 97 or 99 octane, as it is at Tesco, so I put 97 into my mower, and it misfired. I have now discovered that some garages sell e5 at 95 octane, seen that at a Jet and Merco garage in Essex. So that's what I'll use for the boat as my engine is 20 years old and higher octane is not recommended. , getting info from their web sites is not easy, so I'll produce a table soon of which garages still sell e5 at 95 octane.


L'sBelles    -- Aug-22-2021 @ 12:28 PM
  Interesting observation, Marshman.
Back in the days when I had hair, many moons ago now,I used to race 1/5th scale radio controlled cars at international level which were powered by highly modified 22.5cc 2 stroke ex-chainsaw engines. The fastest cars were always using Stihl products and had no discernable smoke from their exhausts so not only were they burning cleaner but appeared to be providing more power too.
Obviously, Stihl would never divulge what oils etc. they were supplying under their label but the top drivers would seek it out in preference to the normal fuel station supplied petrol and 2 stroke oil.

This message was edited by L'sBelles on Aug-22-21 @ 1:29 PM

Paladine    -- Aug-22-2021 @ 12:38 PM
Chicol, my understanding is that E10 petrol isn't being introduced until next month, so E5 regular grade petrol will still be available everywhere at the moment.

Been hit by another boat? Report the incident to the Marine Accident Investigation Branch’s dedicated accident reporting line on 023 8023 2527 which is monitored 24 hours a day.  Help to make the Broads safer.

Karen&Mike    -- Aug-22-2021 @ 5:16 PM
  I will have to check with the technical expert here ( currently busy doing a job for me...) but I think I'm right in saying that the September date for E10 is when it must be available to consumers, but that doesn't preclude (and indeed hasn't stopped) garages from offering/selling it before then.


"Wind up the elastic band Karen - we're setting off!!"

stephenh    -- Aug-23-2021 @ 3:54 PM
  Standard unleaded in my local Sainsbury's is now E10

BuffaloBill    -- Aug-23-2021 @ 6:19 PM
  Got this today after asking the question as my other car won't run on E10.
Hi Bill, E5 petrol will continue to be available at most bp sites (all those selling two grades of petrol) in the ‘super’ petrol grade, bp Ultimate Unleaded with ACTIVE technology, which is labelled as E5. Let us know if you have any further questions? ^FH

The older I get...
The better I was....!!

Karen&Mike    -- Aug-23-2021 @ 10:58 PM
  Yes Bill, I think that was one of the points mentioned earlier - that if you need/want to avoid E10 then going forward you will need to buy the super unleaded type offered at your retailer.


"Wind up the elastic band Karen - we're setting off!!"

annville    -- Aug-24-2021 @ 6:06 PM
  Hi Morrison's at Beccles have both E5 and E10 petrol 97 octane and 95 octane. John

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