E10 petrol

[SV650rules]

You can raise objections to E10 fuel here
https://assets.publishing.service.go...nsultation.pdf


The crafty beggars split up the response form ( annex D ) from the rest - https://www.gov.uk/government/consul...ing-e10-petrol
about halfway down page in link is 'ways to respond and a link to response form...it is a document you need to download and email separately
to the email given on form.... almost seems as though they don't want people to respond....

[SV650rules]

Originally Posted by Kenzie

So by trying to reduce emissions they add more ethanol which increases fuel consumption which then means you burn more fuel to get the same distance so the net effect is emissions remain the same? Why bother?

Another eco-zealot box ticked, another green highlighted bit to put on the UK Powepoint presentation at the next climate change conference where all the delegates arrive by private jet... they do not expect people to question too deeply and unearth the large downsides to most ill-advised government policies..

[embee]

Oh dear.

Why object to the availability of E10 as long as E5 remains widely available ("protected grade")? They're not proposing that the only fuel available will be E10.

As per my earlier post, have a read through the section on E5 availability in the referred to 2020 document before getting too worked up about it.

The vast majority of vehicles built since the 1990's will be fine on E10, and if they are not then just keep using E5 or a premium grade (98RON typically) which will almost certainly have 5% or less ethanol anyway.
Pump fuel has been allowed to contain up to 5% ethanol (or equivalent from oxygenates) for donkey's years but hasn't been required to be labelled.

[Seeker]

Originally Posted by embee

Why object to the availability of E10 as long as E5 remains widely available ("protected grade")? They're not proposing that the only fuel available will be E10.

experience from other European countries shows that petrol stations are reluctant to stock E5 and E10 at regular grades, so you would have to buy the super to get E5.

The proposal is based on the average car being capable of accepting E10, bikes have lagged behind in the sophistication (or adoption) of fuel injection and the article below says that the average age of a bike in the UK is 14.7 years.

https://www.bennetts.co.uk/bikesocia...and-is-it-safe


So, if you have a modern bike, great, you can sit back smugly and enjoy schadenfreude. If you have an older, carb'd bike then "oh dear" is correct.

The proposals have not considered motorcycles at all, it mentions that older cars could have problems and says:

“While there are currently around 400,000 cars that fit the description, this figure is expected to halve by 2021. At that point, these vehicles will represent less than 1% of the total car parc.”

[embee]

I have several older carb bikes, the SV amongst them, so I'm well aware of the potential issues.
E5 will still be available even if it's at the premium grade. On paper the calorific value of the higher grades is usually a couple of percent higher than 95 E5, so in theory the bang-for-buck (MJ/£) isn't that much different. A similar effect applies with oxygenated fuels, complicated a little by those that don't have feedback/closed loop fuelling (to correct A/F for the oxygen in the fuel).
As said in my first post on this, I've used 95E5/95E10/98E5 in various bikes abroad, both FI (NC700) and carbs (650 Deauville) and to be honest the difference in economy has been pretty trivial in reality, and even allowing for the cost/L difference the actual total costs have been mainly down to the type of use (motorway cruising speed for example) and temperature etc rather than the actual fuel price.
Incidentally the NC700 uses 2/3 the amount of fuel that the Deauville uses ridden like for like.

I suppose objecting will make folk feel a bit better, but it's going to happen the way the grubbiment want to do it (remember the outcome of the general election? That's what we get, they want to do something it will happen, tough, "we" voted for it).

[SV650rules]

Higher octane fuel actually has 'less bang for more bucks' - but it allows fuel / air mixture to be ignited earlier for a more complete burn without the rising pressure of burning fuel causing pockets to ignite themselves. The knock sensors on modern engines will detect signature sound of knocking and retard ignition until it stops, but retarded ignition means less power, high octane has less energy but engine can make more efficient use of it. I have tried higher octane 97 and 99 in older carbed bikes and they ran worse, could have been made to run better by advancing ignition timing but that would mean i was then committed to use higher octane.

[embee]

OK, I must be wrong then. My 40yrs in engine design/development was possibly a waste of time.

Seriously though, each to their own, whatever makes people feel happier.

[SV650rules]

Ethanol is used as an octane booster and has less energy than the gasoline it replaces, but it will cool the combustion and reduce NOx - which I guess is the reason for using it, although NOx from petrol engines is already a small fraction of NOx output of diesels

https://global.etsracingfuels.com/bl...tor?loc=global

https://www.sciencedirect.com/scienc...64032113002050

[embee]

We're wandering off topic rather, but there's a lot of incorrect statements in that first link https://global.etsracingfuels.com/bl...tor?loc=global

Just for example, higher octane pump petrol/gasoline is usually slightly higher calorific value, their use of the term "more powerful" is rather odd, it doesn't really mean much. 98RON might be around 43.5MJ/kg, 95RON might be something like 42.7MJ/kg (ref. Bosch Automotive Handbook) but precise numbers are almost impossible to come by, it can vary depending what actual constituents are used.
93RON fuel is not made up of 93% iso-octane and 7% n-heptane, rather it behaves like such a mixture (in a specific test engine at specific conditions). The iso-octane (by definition 100 octane)and n-heptane (by definition zero octane) fuels are the reference fuels against which pump fuel is compared, they are not necessarily or normally the constituents.
Describing the higher octane fuel as behaving more "predictably" is not correct, both or either are usually very predictable in what they do.
Fuel does not "detonate" before the spark occurs. Detonation or knock and pre-ignition are totally different phenomena. Knock occurs in end gas.
Normal combustion is not an "explosion", it is a progressive burn, it takes a few tens of degrees of crank rotation (depending on speed/load etc).

The article is sort of vaguely along the right lines, but rather inaccurate in detail.

[johnnyrod]

Embee is not someone one would waste time arguing with on this subject, to be honest.