Fuel consumption - E10?

[McMr2]

E10 has been available for a couple of months now, but I continue to use super unleaded in the MR2.

However, our other daily hack with a 1.2 TSI engine has seen a marked reduction in mpg over the last few weeks. On a frequent route that used to see an easy 50mpg I now struggle to reach 43/44.

I'm confident it isn't anything hardware related as the car is kept in rude health and running in oil that is less than 500 miles old.

Could it be that winter blend fuel has already reached the pumps? The official word on E10 seems to be a 3% increase in consumption, but if this is a lab figure I'm inclined to think that real world results are much worse. Maybe I'm just cynical.

[Gibla]

Equally cynical here!

I would love to run my various cars on E5 Shell V-Power, but a combination of lack of Shell Garages in my neck of the woods, and a reputed price in excess of £1.60 I use Tesco Momentum on a regular basis(149.9 this am in my local branch)

E10? only when desperately stuck, + only in my stock '2' s if needs be

[AdamR28]

Yes, E10 is less efficient.

[Chilli Girl]

This is interesting or rather disappointing!  Recently, as some of you know I drove upto Scotland in Ange's Honda Civic, previous trips the car was doing 50mpg over a 345 mile trip.  Coming home the other week, 47.8mpg. I put it down to the strong headwind but perhaps it wasn't that afterall! It also cost £70 to fill up, it's never been that much either thanks to the pump prices!

[Carolyn]

We seem to have conducted the experiment. 5% more 'green' alcohol reduces mileage by 5%.

Leave it to the politicians and mandarins to completely screw up on basic engineering.  Again. 

[Joesson]

This is interesting or rather disappointing!  Recently, as some of you know I drove upto Scotland in Ange's Honda Civic, previous trips the car was doing 50mpg over a 345 mile trip.  Coming home the other week, 47.8mpg. I put it down to the strong headwind but perhaps it wasn't that afterall! It also cost £70 to fill up, it's never been that much either thanks to the pump prices!

Not forgetting that Scotland is, on average, higher than England so downhill on the way home, that would make the mpg  differential worse.

[Zxrob]

We seem to have conducted the experiment. 5% more 'green' alcohol reduces mileage by 5%.

Leave it to the politicians and mandarins to completely screw up on basic engineering.  Again. 

Please dont get me started on the f*ckwits

Water down standard fuel and save supposedly xxxx tonnes of CO2, but then we are using more fuel that probably wipes out those savings, in the meantime the treasury coffers grow on the basis the we are saving the world and evidence in the future may well show it to be bolloxx

Rob

[Ardent]

We seem to have conducted the experiment. 5% more 'green' alcohol reduces mileage by 5%.

I tend to recall, predicting this long ago.
Ties in very nicely with the clean fuel thread and a more recent e10 thread.

This thread has saved me digging those up. But as someone that records their every fill. (Read CDO) a stronger version of ocd. (The letters are in the right order.)
My mpg has noticeably reduced on my daily.
By about 5%. Shocker!

Which comes back to. Will your car "run" on E10? Oh yes, no problem at all.
Efficiently/optimally? Chuffing no chance.

[McMr2]

Glad I'm not the only one!!

Turns out my original post was overly optimistic - having double checked the 'official' guidance it actually claims:

"You may see a reduction of around 1%, but it is unlikely to be noticeable in everyday driving."

Staggering.

I suppose time will tell if it is a winter fuel consequence.

[jonbill]

I've done some sums!
not showing my sources (but they're easy to find on the internet)
so: e10 is 3.48 % less energy dense than petrol, so you will use about 3.48% more of it for a given amount of "work" in ideal circumstances.
assuming average 9 carbon atoms per petrol molecule, there is about 4.14% less carbon in e10 than petrol.
using % carbon by mass figures I found on interweb, that suggests 5.75% carbon in e10 than in petrol.

so, with e10 (that is, 10% ethanol) you'll use approx 3.5% more fuel but 4-5 % less carbon per litre of fuel used.
so it should reduce carbon a little. and it'll be 10% renewable fuel.

You cannot view this attachment.

[Dev]

I have used this fuel in my car from day one as it was mandated long ago in my country. The only thing you need to worry about is if you store your car seasonally because it attracts water and will cause phase separation which is a problem. You should use a fuel stabilizer but even more so if you have any small engines that use carburetors be aware it can make older rubber fuel lines brittle and gum up the jets.

[fawtytoo]

Don't the fuel companies add anything already? Seems an obvious thing for them to do.
Edit: Additives I mean.

[McMr2]

I've done some sums!
not showing my sources (but they're easy to find on the internet)
so: e10 is 3.48 % less energy dense than petrol, so you will use about 3.48% more of it for a given amount of "work" in ideal circumstances.
assuming average 9 carbon atoms per petrol molecule, there is about 4.14% less carbon in e10 than petrol.
using % carbon by mass figures I found on interweb, that suggests 5.75% carbon in e10 than in petrol.

so, with e10 (that is, 10% ethanol) you'll use approx 3.5% more fuel but 4-5 % less carbon per litre of fuel used.
so it should reduce carbon a little. and it'll be 10% renewable fuel.

You cannot view this attachment.

Nice!

[Ardent]

I've done some sums!
not showing my sources (but they're easy to find on the internet)
so: e10 is 3.48 % less energy dense than petrol, so you will use about 3.48% more of it for a given amount of "work" in ideal circumstances.
assuming average 9 carbon atoms per petrol molecule, there is about 4.14% less carbon in e10 than petrol.
using % carbon by mass figures I found on interweb, that suggests 5.75% carbon in e10 than in petrol.

so, with e10 (that is, 10% ethanol) you'll use approx 3.5% more fuel but 4-5 % less carbon per litre of fuel used.
so it should reduce carbon a little. and it'll be 10% renewable fuel.

You cannot view this attachment.

Thanks for supplying the numbers to back up what I and others have been saying.
In a nutshell.
Less efficient and more expensive.

[fawtytoo]

More expensive? About 10% more I reckon.

[Ardent]

especially when you take into account you will be back at the pump x% sooner than you would otherwise have been.

[jonbill]

obvs the pricing is completely independent of the chemistry.

[Ardent]

Pricing yes.
More expensive as you are back there sooner. Getting less bang for your £€$

[Petrus]

We seem to have conducted the experiment. 5% more 'green' alcohol reduces mileage by 5%.

I tend to recall, predicting this long ago.
Ties in very nicely with the clean fuel thread and a more recent e10 thread.

This thread has saved me digging those up. But as someone that records their every fill. (Read CDO) a stronger version of ocd. (The letters are in the right order.)
My mpg has noticeably reduced on my daily.
By about 5%. Shocker!

Which comes back to. Will your car "run" on E10? Oh yes, no problem at all.
Efficiently/optimally? Chuffing no chance.

I still prefer a revival of the clean fuel thread as this one is simply the next page and all getting on that page for the first time will lack the previous chapters.

Bottom line is that it is the way it is and part of that is that the official information, whether from the manufacurers or gvt is at nest misleading. Nothing new there either.

[McMr2]

We seem to have conducted the experiment. 5% more 'green' alcohol reduces mileage by 5%.

I tend to recall, predicting this long ago.
Ties in very nicely with the clean fuel thread and a more recent e10 thread.

This thread has saved me digging those up. But as someone that records their every fill. (Read CDO) a stronger version of ocd. (The letters are in the right order.)
My mpg has noticeably reduced on my daily.
By about 5%. Shocker!

Which comes back to. Will your car "run" on E10? Oh yes, no problem at all.
Efficiently/optimally? Chuffing no chance.

I still prefer a revival of the clean fuel thread as this one is simply the next page and all getting on that page for the first time will lack the previous chapters.

Bottom line is that it is the way it is and part of that is that the official information, whether from the manufacurers or gvt is at nest misleading. Nothing new there either.

Went back and read that thread, missed it first time around but some interesting points.

[BARNPOT2000]

Well, I may be a cynical grumpy old sod but it seems that from a politicians point of view its a win win.... They get browny points for carbon emission reduction and if some cars are recked by water in the fuel corroding the systems, hey, its less fossil fuel cars on the road, another browny point... Rant over 🤔.

[Ardent]

Not forgetting some more beans for chancellor.

[BARNPOT2000]

I am doing a very low mileage in the 2 so I'm thinking I should go totally premium unleaded E5 from now on despite the excessive cost. Theory being the extra cost will be less than a damaged engine?

[Beachbum957]

There seems to be a large amount of misinformation on E10 and similar fuels.  While some much older vehicles and a few cars built for limited markets could have issues, E10 has been sold in the US for 2 decades and is basically the only fuel available in most markets.  Virtually none of the doomsday predictions being suggested in some literature have come to pass. After nearly 20 years of use, the effects (or non-effects) are well documented.  E15 is now available in many areas and much more common than ethanol free.  Initially, there were predictions of doom with E15, but people have been using E15 deliberately or even accidentally form years now with no issues.

https://axleaddict.com/cars/Is-E15-Ethanol-Bad-For-Your-New-Cars-Engine-Lets-Review-The-Facts

https://vitalbypoet.com/stories/what-you-need-to-know-about-using-e15

The one fact in all of the articles is the cars with no issues are built for US specifications and standards (excluding California).  For the most part, if a car model is sold in the US, it is probably built to the same or similar specs world wide.  If it isn't, then perhaps there may be an issue, but that situation should be pretty rare.  If you examine Toyota's for example, fuel systems and other related systems are the same worldwide.

The other problem is cost. There are a very few stations in our area in the US selling ethanol free fuel and it is very hard to find, but it is more than 10% more expensive in an equivalent octane grade in E10. Even if it gives better real world mileage, it would be very hard to justify the extra cost, and the difficulty in finding it. 

There are more EV charging stations than gas stations selling ethanol free fuel, and they are very hard to find as well!

[Ardent]

Out of curiosity.

What is the unit price of fuel where you are?

See if we can have some fun with numbers.

It is priced per litre here.
Much variation across the country but lets say 143p/litre.

4.54l to the UK gallon
So 649.22p £6.49

3.785l to a US Gallon.

Things to play with.
UK gallon vs US gallon
£/p vs $/c
Exchange rates

Over to our US members for some local figures.