Anybody been measuring mpg differences E5/E10?

[clanger]

Feb 4, 2022 19:42:21 GMT ChasR said:

Feb 1, 2022 20:17:02 GMT clanger said:

I run on E85 here in France mixed 50/50 with E10, the emissions are at near zero on the test like you say.  The car loves it (mondeo 2.5T) and goes like a rocket plus its 70 cents a liter.  Drops the consumption from 29 mph to 23 mph ( LTFT goes out to +12) but the cost and performace increase are worth it.  I have remapped my Fiat Coupe 20VT to run on it 100%,  huge increases in ignition advance on full boost - I think its the mondeo ECU advancing the timing that has improved the performance.  Great fuel.

The knock sensor in the Mondeo would affect a few things
-Ignition Timing
-Boost
-Cam timing (both cams have VCT)

Indeed it would, along with a WB O2 but they are only sensors and (with the exception of the WBO2) they existed back in the 90s.  A more modern ECU such as Bosch ME9 can advance the timing significantly until it senses knock and then back off.  The old Bosch Motronic 2 in the Fiat can only advance to a set point and then retard the timing in the event it senses knock via knock sensors, it cannot go past a certain limit defined in the fixed ingnition maps. 
The only "classic" cars burned by E10 here in France have it poured on them rather than in them around new years eve

[flyingphil]

I do a regular cross country run of 25 miles. Driving reasonably steadily on quiet roads. I used to just reach 30 mpg each time (SLK 350). Now I have had two or three tanks of E 10, I am struggling to get over 28 mpg. My average speed is the same so is it me or is it the E 10?
If it is the E 10, how is it environmentally better if I am needing more fuel?

[ChasR]

Feb 5, 2022 13:51:50 GMT flyingphil said:

I do a regular cross country run of 25 miles. Driving reasonably steadily on quiet roads. I used to just reach 30 mpg each time (SLK 350). Now I have had two or three tanks of E 10, I am struggling to get over 28 mpg. My average speed is the same so is it me or is it the E 10?
If it is the E 10, how is it environmentally better if I am needing more fuel?

Emissions, or specifically, tailpipe emissions.

Yes, you can remap your car, but will it pass the emissions standards set by the bodies, and not just an MOT? Probably not. From memory, NOx emissions are a byproduct of hotter exhaust gasses.

I guess a good analogy may be is how a tyre is destroyed. Is it healthier to burn the rubber doing an amazing burnout or is it better to set fire to it, as is done in developing countries, with known health issues attached.

[rattlecan]

Feb 5, 2022 13:51:50 GMT flyingphil said:

I do a regular cross country run of 25 miles. Driving reasonably steadily on quiet roads. I used to just reach 30 mpg each time (SLK 350). Now I have had two or three tanks of E 10, I am struggling to get over 28 mpg. My average speed is the same so is it me or is it the E 10?
If it is the E 10, how is it environmentally better if I am needing more fuel?

That’s the elephant in the room. They like to tell you it is more environmentally friendly, it can’t possibly be. Not just the lower mpg, but just imagine all the rubber parts everyone is fitting & going to fit. Thousands of container loads shipped all over the planet. It’s total nonsense

[melle]

Feb 5, 2022 13:51:50 GMT flyingphil said:

how is it environmentally better if I am needing more fuel?

This is a hell of a fallacy, but you probably knew that when typing it.

[rattlecan]

Feb 5, 2022 16:31:33 GMT melle said:

Feb 5, 2022 13:51:50 GMT flyingphil said:

how is it environmentally better if I am needing more fuel?

This is a hell of a fallacy, but you probably knew that when typing it.

So do tell

[melle]

Feb 5, 2022 16:51:02 GMT rattlecan said:

So do tell

If you could replace 1l of your favourite fuel with 2l water to run your car, mileage would be half as good/ you'd need twice as much volume, but it would surely be more environmentally friendly?

[kevins]

Ethanol is there to reduce co2 because it is derived from plants which in theory grow again and re-absorb the co2. Co2 is directly proprtional to the amount of fuel burnt, so if you use 5% more fuel on e10 than e5 it is of no benefit at all. Ethanol is still a hydro carbon so you still get all the other nasties.

[VIP]

The 'energy' value between E5 and E10 is almost indistinguishable.

Ethanol has approximately 66% of the energy of the same volume of pure gasoline, which sounds a lot until you realise the change in volume mix is only 5% more ethanol.

So the reduction of energy between the same volume of E10 compared to E5 is 1.73%

[melle]

I think E10 does more harm to drivers' resistive minds than it does to cars.

[welshpug]

Feb 5, 2022 13:51:50 GMT flyingphil said:

I do a regular cross country run of 25 miles. Driving reasonably steadily on quiet roads. I used to just reach 30 mpg each time (SLK 350). Now I have had two or three tanks of E 10, I am struggling to get over 28 mpg. My average speed is the same so is it me or is it the E 10?
If it is the E 10, how is it environmentally better if I am needing more fuel?

its winter

[comfortablynumb]

Feb 8, 2022 10:10:50 GMT welshpug said:

Feb 5, 2022 13:51:50 GMT flyingphil said:

I do a regular cross country run of 25 miles. Driving reasonably steadily on quiet roads. I used to just reach 30 mpg each time (SLK 350). Now I have had two or three tanks of E 10, I am struggling to get over 28 mpg. My average speed is the same so is it me or is it the E 10?
If it is the E 10, how is it environmentally better if I am needing more fuel?

its winter

But colder denser air is supposed to be better? 🤔

[flyingphil]

Feb 8, 2022 10:19:23 GMT comfortablynumb said:

Feb 8, 2022 10:10:50 GMT welshpug said:

its winter

But colder denser air is supposed to be better? 🤔

.......and I have been doing the same regular trip for three years, Winter and Summer.

[vitesseefi]

Winter/summer definitely makes a difference. A lot of it is in the warm-up times so shorter journeys more affected.

Also, when I was comparing energy density earlier on, I forgot to mention the differences between stoichiometric ratios. 14.7 for straight petrol and 9:1 for ethanol. So that 38%greater volume of ethanol required for a stoichiometric burn.

For E10 at the full 10% allowed that equates to just under 4% increase in volume of fuel required. However individual engines respond will involve many other factors though.

As stated earlier, I’m also doubtful that much of the E10 on sale in the UK actually contains 10% ethanol, but happy to be proved wrong if anyone has been testing or has other evidence.

Nick

[VIP]

Feb 8, 2022 13:53:39 GMT vitesseefi said:

For E10 at the full 10% allowed that equates to just under 4% increase in volume of fuel required. However individual engines respond will involve many other factors though.

Is that comparing 10% ethanol against straight gasoline, or against 5% ethanol?

If against straight gasoline then comparing E10 to E5 will result in half that increase, or close to the 1.73% difference I noted above.

[vitesseefi]

Against straight petrol, so yes, half that for E5.

Nick

[Jonny69]

What does E10 actually save us then? I do numbers. Let's do some numbers. Basic Google says there are 32 million licensed cars on the UK roads, of which 12.9 million are diesel. Let's round that to 30 million total, 13 million are diesel = 17 million petrol cars.

Average UK mileage is apparently ~7400 miles per year. Let's say the petrol ones average 40mpg (it'll be nowhere near that, but let's use it for argument's sake because it's a fairly round number).

Total number of miles travelled: 17,000,000 x 7400 = 125,800,000,000 miles

Total number of gallons of petrol: 125,800,000,000 / 40 = 3,145,000,000 gallons

Total number of litres of petrol: 3,145,000,000 x 4.54 = 14,278,300,000 litres

E10 saves using 10% of that = 14,278,300,000 x 0.1 = 1,427,830,000 litres

Weight of that (assuming petrol weighs about 0.7kg per litre) = 1,427,830,000 x 0.7 = 999,481,000 kg = 999,481 tonnes

So, ballpark, E10 saves using nearly ONE MILLION tonnes of petrol each year in the UK. That's quite a lot.

Tank in this is 28 litres:



Assuming I did ~5000 miles a year like I used to, with an average fuel consumption of 35mpg (less in town), how long would one year's worth of saved petrol last me?

314,500,000 gallons / 35 = 8,985,714 miles

8,985,714 miles / 5000 miles PA = 1,797 years.

Plenty to see me through then. Nothing to worry about.

[VIP]

Feb 14, 2022 14:28:45 GMT Jonny69 said:

What does E10 actually save us then? I do numbers. Let's do some numbers. Basic Google says there are 32 million licensed cars on the UK roads, of which 12.9 million are diesel. Let's round that to 30 million total, 13 million are diesel = 17 million petrol cars.

Average UK mileage is apparently ~7400 miles per year. Let's say the petrol ones average 40mpg (it'll be nowhere near that, but let's use it for argument's sake because it's a fairly round number).

Total number of miles travelled: 17,000,000 x 7400 = 125,800,000,000 miles

Total number of gallons of petrol: 125,800,000,000 / 40 = 3,145,000,000 gallons

Total number of litres of petrol: 3,145,000,000 x 4.54 = 14,278,300,000 litres

E10 saves using 10% of that = 14,278,300,000 x 0.1 = 1,427,830,000 litres

Weight of that (assuming petrol weighs about 0.7kg per litre) = 1,427,830,000 x 0.7 = 999,481,000 kg = 999,481 tonnes

So, ballpark, E10 saves using nearly ONE MILLION tonnes of petrol each year in the UK. That's quite a lot.

Half that, unleaded petrol already had 5% ethanol in it before E10. Still significant though.

[blackpopracing]

My 2007 Mondeo does exactly the same on E10 as E5. I don't bother resetting the average very often (approx every 2-3000 miles) and its steady at 34.7 most of the time at present (which is good for winter as it's normally around 32.5).

Warm up is a killer for engines - I can see a 0.3mpg drop in the first 5 mins of running on a -4 degree morning, it can take 50 odd miles of motorway driving to get it back up again.

As it's been a mild winter that's where my higher average MPG is from.

Performance wise in the Mondeo- exactly the same.
Performance wise in the Pop - it runs fine on E10, but runs noticably better (when used hard) on Super Plus type fuels.

[carledo]

Feb 14, 2022 14:28:45 GMT Jonny69 said:

Tank in this is 28 litres:



Assuming I did ~5000 miles a year like I used to, with an average fuel consumption of 35mpg (less in town), how long would one year's worth of saved petrol last me?

314,500,000 gallons / 35 = 8,985,714 miles

8,985,714 miles / 5000 miles PA = 1,797 years.

Plenty to see me through then. Nothing to worry about.

Just having a quiet chortle at the thought of doing nearly 9 million miles in a 105E! By my calculation that's nearly 25 engines!  And who knows how many breakdowns?

Steve