Ethanol vs Ethanol FREE gas mpg?

[Piotrsko]

Unfortunately the lower emissions come at a cost to total emissions because you become less efficient

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Unfortunately the lower emissions come at a cost to total emissions because you become less efficient

Also considering how the logistics may increase the footprint of a presumably "cleaner" fuel, due to the increased amount of tanker-truck trips necessary to supply gas stations with either pure ethanol or some high-ethanol blend such as the E27 mandatory in Brazil, it does become a matter of concern. Had either other feedstocks such as corn being more widely used for ethanol brewing, and smaller distilleries being more widespread at a regional level decreasing the miles the fuel would have to be hauled until it reaches the customer, ethanol could've still be taken more seriously.

[freebeard]

Is this the most recent thread about ethanol?

America Was Wrong About Ethanol - Study Shows

White board talk, confirms my suspicion.

[aerohead]

The straight gasoline would have a heating value in the neighborhood of 117,427-Btu/gallon vs 111,836-Btu for REGULAR UNLEADED E10.
So the engine 'see's' 4.76% less available chemical energy coming in, requiring the difference be made up in more fuel mass per brake-horsepower-hour of work.
A difference in OCTANE rating might allow a high-compression engine to operate without destructive detonation, increasing it's thermal efficiency, and cancelling the loss in the difference in Btus.
It would 'all depend.'
'Specificity.'

[cRiPpLe_rOoStEr]

When my stepmother's oldest son inquired me about a rumor that any car with EFI would in fact be flexfuel, one of the aspects I pointed out to him was ethanol being used to bump the octane rating up of the lower-grade gasoline available in Brazil. However, as ethanol is classified as an "oxygenate", a larger amount of ethanol would lead the O² sensor to throw an error code even if the engine would be still running smooth.

[Piotrsko]

Afaik, on a flex fuel usa car, the conditions map was increased to accept out of parameter temperature conditions caused by the alcohol. IE: different exhaust temps with no corresponding other symptoms would now be acceptable then add more or less fuel. Suspect the after cat egt probably stays the same.

Not a computer mechanic, but can play one on the internet

[bwilson4web]

This is a better description of straight gas vs E85:

Why Does Ethanol Make So Much Power? (Versus Gasoline)

I had done some benchmarks mixing E10 and E85 to test different ethanol ratios using our 2003 and 2010 Prius:

• straight gas - expensive and poorest hill climb performance
• E10 - much more affordable than E85
• E50 - highest ratio that did not cause a check engine light
• E85 - best hill climb performance but highest cost and threw a benign check engine code, injector on too long

Bob Wilson

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Afaik, on a flex fuel usa car, the conditions map was increased to accept out of parameter temperature conditions caused by the alcohol. IE: different exhaust temps with no corresponding other symptoms would now be acceptable then add more or less fuel.

It's the same elsewhere. What I meant is, as most cars with EFI have oxygen sensors anyway, some folks actually tried to run on ethanol on non-flexfuel models expecting the EFI and ignition to compensate. Sure a CEL might be triggered once the ECM is not programmed specificly to handle a higher amount of ethanol.