Energy in Ethanol v Gasoline?

[Paul in Qatar]

Someplace (Car & Driver?) I read something along the lines of:

The trouble is that Ethanol only has 65% or the energy per gallon of gasoline, but does not cost 65% as much.

I have forgotten the correct figure. Anyone out there know?

[Tapioca Dextrin]

These are DOE figures

Gasoline 125,000 Btu/gal(gross) = 115,400 Btu/gal(net)

Hydrogen 134,200 Btu/kg(gross) = 113,400 Btu/kg(net)

Diesel 138,700 Btu/gal (gross) = 128,700 Btu/gal (net)

Biodiesel 126,206 Btu/gal (gross) = 117,093 Btu/gal (net)

Methanol 64,600 Btu/gal (gross) = 56,560 Btu/gal (net)

Ethanol 84,600 Btu/gal (gross) = 75,670 Btu/gal (net)

Gasohol 120,900 Btu/gal (gross) = 112,417 Btu/gal (net)




The energy bit is easy (75670/115400 = 0.655 or 65%)

the costs are a little less scientific in their numbers (it depends how much government subsidy you want to include in the figure, for instance)

[Paul in Qatar]

Gee! I guessed right! (That is to say E85, "Gasohol" is worth 65% of the real deal?

[Xema]

E85, "Gasohol" is worth 65% of the real deal?
Since it's 85% ethanol, 15% gasoline, the energy content would be just over 70% that of pure gasoline.

[Paul in Qatar]

Thank you.