Alcohol fuels vs gasoline, in addition to the great info on caloric values also comes down to the stoichiometry. Gasoline stoichiometric values are 14.7:1, meaning 14.7 parts air to 1 part gasoline for optimum combustion.
Ethanol is 9:1, and methanol is 6.47:1.
In other words, you can stuff more alcohol into the charge at ambient pressure (naturally aspirated). The effects are realized even more when using forced induction.
This is why top fuel dragsters are making 11,000 HP with only a 500 cubic inch motor. Nitro methane, while also having less BTU than equal volume of gasoline (gasoline has 18,400 BTU/lb, nitro is only 5,000 BTU/lb) has a stoichiometric value of 1.7:1 !! That means they can stuff a little over 8.5 times as much nitro per charge than gasoline. Using that stoichiometric value, you can burn the equivalent of 43,000 BTU of nitro to gasoline's 18,400. Add forced induction to increase amount of air, you can then use even more nitro per charge and the difference is even greater. Lots more HP!
Several of the auto manufacturers are making "flex fuel" vehicles that allow you to run E85. I know the Chevy 5.3 liter engine stock on gasoline is rated at 355 HP. Run E85 in it and it is rated at 380HP, but the kicker is, your mileage suffers too because it's drinking more of the corn fuel due to the stoichiometry.
Ethanol is 9:1, and methanol is 6.47:1.
In other words, you can stuff more alcohol into the charge at ambient pressure (naturally aspirated). The effects are realized even more when using forced induction.
This is why top fuel dragsters are making 11,000 HP with only a 500 cubic inch motor. Nitro methane, while also having less BTU than equal volume of gasoline (gasoline has 18,400 BTU/lb, nitro is only 5,000 BTU/lb) has a stoichiometric value of 1.7:1 !! That means they can stuff a little over 8.5 times as much nitro per charge than gasoline. Using that stoichiometric value, you can burn the equivalent of 43,000 BTU of nitro to gasoline's 18,400. Add forced induction to increase amount of air, you can then use even more nitro per charge and the difference is even greater. Lots more HP!
Several of the auto manufacturers are making "flex fuel" vehicles that allow you to run E85. I know the Chevy 5.3 liter engine stock on gasoline is rated at 355 HP. Run E85 in it and it is rated at 380HP, but the kicker is, your mileage suffers too because it's drinking more of the corn fuel due to the stoichiometry.
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