Are any of you noticing a fuel economy impact running E10?

Caporegime
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Soldato
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That's not What Car and is from 2014. Also says compared against pure unleaded.

Wonder what happened to the original article? Unless you can find it on what car I will assume they removed it out of embarrassment because the research is obviously complete BS with any level of common sense. Unfortunately people writing for these publications aren't always scientifically literate.

E10 fuel is regularly used in the US and also Mainland Europe and has been for a long time. Us Brits aren't discovering some new found insight.
 
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Caporegime
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V Power was £1.63 a litre the last time I pulled into a shell so E10 it was, only noticed the normal drop in MPG I get when it's this cold.
 
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Lab engine tests aren't real world. And I doubt every model of car including older cars has been lab tested?

In their "real world tests" it was the Lancia Sandero which lost 11.5% of its mpg and the Hyundai i30 lost 9.8%

Perhaps newer Lancia's are better as this was a 2015 car. Perhaps manufacturers have made modifications to take account of E10 since they new it was coming?

Doesn't help you if you own an affected used car and lose 11.5% of your mpg though

Surely in this case lab tests are the only reliable metric to use? I know that when comparing manufacturer's wider economy claims, it might be valid to cite real world experience. Because those general claims can be affected by a raft of variables which can't necessarily be accounted for in a fixed laboratory environment.

But if you only have one variable to test - if the ethanol content affects efficiency - then surely a lab test is the best and most fair way to judge that?
Place the engine on a dyno. Test it's output on E5 fuel. Then test again, with the only difference being changing the fuel to E10. Measure the difference and you know precisely how the ethanol content affects the engine output, and therefore, it's efficiency.

Surely "real world" testing is untrustworthy, because as has been pointed out, the switch to E10 has coincided with the autumn/winter seasons. Not only that, but rumours of reduced efficiency have bene circulating since before the switch. Measuring a car's economy is a tricky thing to do accurately, and can be affected by subjectivity - if lots of people already believe E10 is going to lead to reduced economy because that's what they've heard, it doesn't take much for them to start blaming that if they do see their economy drop even a little.
 
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Surely in this case lab tests are the only reliable metric to use? I know that when comparing manufacturer's wider economy claims, it might be valid to cite real world experience. Because those general claims can be affected by a raft of variables which can't necessarily be accounted for in a fixed laboratory environment.

But if you only have one variable to test - if the ethanol content affects efficiency - then surely a lab test is the best and most fair way to judge that?
Place the engine on a dyno. Test it's output on E5 fuel. Then test again, with the only difference being changing the fuel to E10. Measure the difference and you know precisely how the ethanol content affects the engine output, and therefore, it's efficiency.

Surely "real world" testing is untrustworthy, because as has been pointed out, the switch to E10 has coincided with the autumn/winter seasons. Not only that, but rumours of reduced efficiency have bene circulating since before the switch. Measuring a car's economy is a tricky thing to do accurately, and can be affected by subjectivity - if lots of people already believe E10 is going to lead to reduced economy because that's what they've heard, it doesn't take much for them to start blaming that if they do see their economy drop even a little.

Unless people have totally drained their tanks before moving to E10 it's not going to be a sudden drop down in ethanol content either. It might take months to see the full impact.
 
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Unless people have totally drained their tanks before moving to E10 it's not going to be a sudden drop down in ethanol content either. It might take months to see the full impact.

Yes, exactly. Whereas in a lab, you can precisely gauge exactly how much of each fuel is used in a controlled test.
 
Caporegime
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And what car wasnt the only one.

Finnish car magazine also found a 3% drop on average and got into a heated argument with the Govt dept who stated it was impossible to have more than 1.5% to 2% decrease.

https://www.euractiv.com/section/transport/news/test-shows-e10-increases-fuel-consumption/

Interesting that What Car stated it was the smallest engines (1l) that had the worst affect resulting in a 10% drop in mpg.

End result is that since the fuel hasnt gone down people are going to be getting 3% on average worse economy on average and "some" cars may be up to 10%.

It all seems similar to when VW launched the blue eco golf. We had the old 140bhp 2l diesel golf and could get easily 50+ and sometimes 60mpg from it but the new 1.6L 100bhp that was much lower emissions and promised much better fuel economy actually achieved worse fuel economy. Could never get it past 50mpg and was normally at best in high 40s.

Reason being was the engine was so underpowered so if travelling with more than one person and living in a hilly area, your fuel economy plummeted. Lab tests would suggest otherwise.
 
Caporegime
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Unless the conditions were identical, temp, weather, style of driving, traffic etc it's pointless to pin the entire drop in economy on E10 alone.

I go from 37ish to 30 over winter. Shorter trips, longer to warm up.

Well I am sure the testers didnt test one car in summer and the other in winter!

And the finnish magazine had trained drivers and went over a set course/similar weather conditions etc.
 
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Surely in this case lab tests are the only reliable metric to use? I know that when comparing manufacturer's wider economy claims, it might be valid to cite real world experience. Because those general claims can be affected by a raft of variables which can't necessarily be accounted for in a fixed laboratory environment.

But if you only have one variable to test - if the ethanol content affects efficiency - then surely a lab test is the best and most fair way to judge that?
Place the engine on a dyno. Test it's output on E5 fuel. Then test again, with the only difference being changing the fuel to E10. Measure the difference and you know precisely how the ethanol content affects the engine output, and therefore, it's efficiency.

Surely "real world" testing is untrustworthy, because as has been pointed out, the switch to E10 has coincided with the autumn/winter seasons. Not only that, but rumours of reduced efficiency have bene circulating since before the switch. Measuring a car's economy is a tricky thing to do accurately, and can be affected by subjectivity - if lots of people already believe E10 is going to lead to reduced economy because that's what they've heard, it doesn't take much for them to start blaming that if they do see their economy drop even a little.
Exactly. Even things like Fuel temperature and ambient pressure (exhaust back pressure. Not just intake ) also have big impacts on fuel economy. There are so many parameters to control to enable the test to be fuel vs fuel rather than other factors.
 
Soldato
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Well I am sure the testers didnt test one car in summer and the other in winter!

And the finnish magazine had trained drivers and went over a set course/similar weather conditions etc.

How do you know this? I can't find any more details on the test in that article, they just say it will be published on 30th March. I clicked the link to the magazine, but it gave a 404 error. Is there another link I've missed somewhere?
Not trying to trip you up, I'm genuinely interested. The article claims it was a "laboratory test", but to me, that means something like I suggested above, a controlled and precise test on an engine dyno, not taking the car out and driving it around. I accept that might not be everyone's definition though.
 
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Unless the conditions were identical, temp, weather, style of driving, traffic etc it's pointless to pin the entire drop in economy on E10 alone.

I know my car. The difference was night and day, I'm not going to argue with any derp that disagrees as I've physically had the experience.
Also my engine idles like **** on it, I actually thought I had a misfire until I remembered, ah yeah, that new fuel!

People blindly believing lab results because some **** in a suit said something is something is genuinely full retard.

As we know, you NEVER go full retard.
 
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Unless the conditions were identical, temp, weather, style of driving, traffic etc it's pointless to pin the entire drop in economy on E10 alone.

I go from 37ish to 30 over winter. Shorter trips, longer to warm up.

Sure.. Sure.. True.. True..

Except I know my car and the difference was night and day, other cars may be different but a 211ps 2.0tfsi quattro TT does NOT like this slurp.
 
Caporegime
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I know my car. The difference was night and day, I'm not going to argue with any derp that disagrees as I've physically had the experience.
Also my engine idles like **** on it, I actually thought I had a misfire until I remembered, ah yeah, that new fuel!

People blindly believing lab results because some **** in a suit said something is something is genuinely full retard.

As we know, you NEVER go full retard.

So your car has a misfire, definitely the fuel then.

I dropped a box of eggs at the weekend, sodding E10.
 
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