[ds093]

yep, spot on

BUT those pesky enviromentalists prefer e10 as it is a quick easy win for CO2 reduction as the ethanol is "supposed to be from sustainable sources" and govt's see it as a quick win for their emission targets

I've read that in my home province of Ontario, the provincial legislature has regulated that all fuel stations must sell at least 2/3 of their gas with 10% ethanol. As most people only buy the lower octane due to price, some are able to sell their higher grade ethanol free.

 

[SEvans]

yep, spot on

BUT those pesky enviromentalists prefer e10 as it is a quick easy win for CO2 reduction as the ethanol is "supposed to be from sustainable sources" and govt's see it as a quick win for their emission targets

Pesky environmentalists don't seem to be very clever. To achieve the same power rating (or speed, or acceleration) the ICE now needs to be revved higher, lowering fuel consumption still further from the 10% loss before, adding to global warming an increasing emissions. More than offsetting the supposed reduction in fuel consumed.

I'm sure in their own tiny minds they think they're helping...

The only way to reap the benefits of ethanol is to optimise the ignition system and the engine for it, then run it exclusively on it. It's still less efficient but the emissions are less.

 

[litesong]

Yes the calorific content of ethanol is lower than that of pump fuel, so when it is added it does have an effect on overall consumption.

The caloric content of ethanol is 3% lower than E0. Adding 10% ethanol to E0 would only lower MPG by 0.3%. The difference between E10 & E0 MPG is ~ 8% to 5%. 87 octane gasoline engines work best with 87 octane gasoline, E0. Defined 87 octane E10 is actually a combination of 114 octane ethanol molecules & 84 octane gasoline molecules, neither of which are 87 octane. It is the combination of ethanol lower caloric btus(small effect) AND the mis-matched octanes (much greater effect) that cause the total 8% to 5% MPG difference between defined 87 octane 10% ethanol blend & truthful 87 octane E0.

 

[SEvans]

The caloric content of ethanol is 3% lower than E0. Adding 10% ethanol to E0 would only lower MPG by 0.3%. The difference between E10 & E0 MPG is ~ 8% to 5%. 87 octane gasoline engines work best with 87 octane gasoline, E0. Defined 87 octane E10 is actually a combination of 114 octane ethanol molecules & 84 gasoline molecules, neither of which are 87 octane. It is the combination of ethanol lower caloric btus(small effect) AND the mis-matched octanes (much greater effect) that cause the total 8% to 5% MPG difference between defined 87 octane 10% ethanol blend & truthful 87 octane E0.

Well calorific content also affects flame propagation - or the nature of the `spark` - so there is more to it than the characteristics of the fuel in it's potential state but your point is well made - it's the mixture that lacks consistency. And mostly that's because the Ethanol is hydrophilic.

Ideally all ethanol based fuels should be sold with a `sell-by` and `use-by` date, like foodstuffs. :nerd:

 

[litesong]

So my question is would it not be better to get the E0 91 octane over the E10 87 octane?

It would. However, if Canada is similar to the U.S., the gov't, bought off by the ethanol industry, penalizes oil companies for producing E0 & that is why E0 costs almost an extra $1 per gallon.
One might think then, that oil companies would protest blending ethanol into gasoline. However, more oil is used producing ethanol than ethanol can possibly save oil. Yeah, the oil industry loves to blend ethanol into their gasolines. More oil is used AND it produces an entire "ethanol in gasoline" industry.

 

[LocoMk700]

Hm, those geeky Koreans must be doing something to these engines cause where I live, the regular fuel is 95 octane, while premium is 98.
Can't otherwise explain why it's not advised to use 93 octane fuel in NA and 87 instead, all the while Europe goes on 95 as standard.

 

[bluecar1]

in UK the fuel spec is 95RON which roughly equates to US 87 octane

you need to be careful to compare apples with apples

its all marketing BS, as 95 is a bigger number so must be better than 87 although they are different measure which are in fact the same (see windows, iPhone etc numbering)

 

[Halo]

I'm an eco-nut and sad about ethanol. Less emission while running but I have to use more of it to go the same distance. Reading through, looks like my recent post about sudden mpg drop might be answered. I'll drive by the fuel station and see if they did switch over. I was more excited about the dollar amount!

 

[litesong]

....it's the mixture that lacks consistency.

87 octane gasoline engines can't efficiently use 114 octane ethanol molecules & 84 octane gasoline molecules to produce power.

 

[LocoMk700]

in UK the fuel spec is 95RON which roughly equates to US 87 octane

you need to be careful to compare apples with apples

its all marketing BS, as 95 is a bigger number so must be better than 87 although they are different measure which are in fact the same (see windows, iPhone etc numbering)

Of course, I was only talking about engine tuning to different fuel octane, that's all
If standard in US is 83 octane, and Kappa runs fine on them, then I guess something must be adjusted for Europe to cope with 95 octane equally reliably.
I'm not an engineer, though, so have no idea what would that be. Air/fuel mixture? Some additives?

 

[litesong]

.... in the U.S. cities in high elevation areas have 85 octane as well, as less octane is needed at higher altitudes which would be comparable to 87 octane.

Here at Salish Sea (Puget Sound) sea level, 87 octane works the very best for my last 5-6 cars, whether using E0 (ethanol-free) or E10 (10% ethanol blend). For years I've been curious about 85 octane at higher altitudes, but haven't had recent high elevation vacations to test 85 octane gasoline. I most would like to test 85 octane E0 (all gasoline molecules are 85 octane), believing it superior to 85 octane E10. As it is, 85 octane E10 is a mixture of 10% 114 octane ethanol molecules AND 82 octane gasoline molecules (which would be spooky).

 

[IsntItIoniq]

in UK the fuel spec is 95RON which roughly equates to US 87 octane

you need to be careful to compare apples with apples

its all marketing BS, as 95 is a bigger number so must be better than 87 although they are different measure which are in fact the same (see windows, iPhone etc numbering)

They're related numbers. Europe and I believe most of the world uses RON. MON is another unrelated measure. The US (and I think Canada) use AKI which is an average of the two.

 

[coverman]

Very difficult to accurately compare fuel consumption of different fuels without having consistent conditions throughout the tests, ie you need a to do it in a lab with constant ts and ps. Just because you got longer range from a thankful of one gas compared to the previous thankful of another brand is meaningless because the environmental conditions, traffic, route etc would all have to be identical to make a fair comparison, something that can never be done in practice.
I have done huge mileages in my cars using mainly supermarket fuels, 450000 in the case of my Renault on the original engine, still running well when sold, by fastidious oil/filter change intervals, never revving hard until full temperature reached, avoiding very short journeys to minimise that condensation effect on exhaust and engine oil. This saved far more money in repairs than all the hypermiling and worrying about using heavily advertised fuel brands would have done. Never had any problems whatsoever with clogging of fuel pumps, valve gear etc in the last 3 cars which between them totalled over a million miles run.
Hope I haven't jinxed this Ioniq by writing the foregoing!!

 

[coverman]

I do use Shell V Max, only, in my Brabus Smart, but is in a relatively high state of tune,about 16 per cent beyond factory output, and in my Sports racing car which is running 11 to1 compression.Every day cars filled up whenever I see low priced fuel and need more than 4 gallons