BTU is a unit of measurment for heat. Ethanol does not produce the same amount of heat (read: engergy) as gasoline. An engine running on Ethanol will get LESS gas milage because it takes MORE of it to run the engine. While its octane level is very high, something like 109, its power output is very low which is why you have to have more Ethanol fuel in the air mixture, which means less gas milage.
If we can produce a super ethanol that will yeild us the same power as gasoline, make it cheaper, cleaner, and more abundant, then the only thing we need to do with oil is change it every 4k miles or so.

BTW, Big Al is promoting the 4,000/4 Month oil change. Average car uses a gallon of oil every oil change. By moving from 3 to 4k miles, you save about a gallon of oil every year. If everyone in America went to 4k or more between oil changes, that would save 300 million gallons of oil.
Most new cars have oil life monitors, in which either a computer algorythm or by sensor can tell you when to change your oil. I know my Maxx was over 5k between oil changes. Some cars are said to do it every 10k.
Reduce oil use, which has to be disposed of somehow. At least gasoline is burned off. Oil has to be transported and all this other crap.

BTU/(unit time) is the unit used when talking about power. It can be converted to Watts, Joules, and other types of energy. BTUs with no unit time are talked about for HVAC stuff and heat.

Given proper conversions, 1 HP is a little over 2500 BTU/h. So I believe that if you have a test mule engine with all else being equal (displacement, RPM ramp during testing, duration of testing, etc) and you vary the fuel, whichever fuel generates less BTUs will generate less power.

ok so your saying if a chemical expands 10x its size during combustion but makes less heat it will create less pressure than a chemical that expands 8x is size and creates more heat.

(not Accurate #, just examples)

Its a measurement of energy. Just because it can compress and expand doesnt give it any more energy. The amount of energy ethanol fuel gives off when burned is less then when gas is burned in a combustion engine.
There are been improvements with direct injection and turbocharging where they can make much more power. Saab showed a 300-400hp turbocharged engine using E100.

Not completely sure I follow you. We are talking energy, not heat.

If fuel A combusts with force X and fuel B combusts with force .8X, fuel A will throw the pistons harder per unit time.

We can all keep dreaming but its not going to happen. If it does it will be when it is already to late.

that exactly what i just said...there talking about heat...if fuel A combusts with force X and heat .8X and fuel B combusts with force .8x and heat X. Fuel A is more efficient right?

heat = energy

Let me try this again. It's been a while since I took Physics.

According to Physics and its Unit Conversions, ~2500 BTUs/hr equal one horsepower.

If you burn one gallon of ethanol and gasoline in an hour,

Gasoline = 114,100 BTU or 45 HP
E85 = 81,800 BTU or 32.72 HP

Therefore, to acheive the same performance you need to burn more ethanol.

ok...your measuring power output of the actual burning...thats not how it works in an engine...cylinders and piston work off the explosive properties not the heat emissions. what if there was a fuel that could explode 50X its volume in a combustion cycle and only produce 1BTU/h. are you saying you would need more of that? heat is a byproduct of combustion, we all know that, internal combustion engines do not run off heat now do they, the run off the explosive expansion of a compressed vapor.

Bubba,

I'm not basing this off of anything other than Physics. You can argue all you want but that's the way it is. You are confusing what factors are actually at work. I think you are confusing BTUs with BTUs/hr. This is a reason why people use Joules when talking about a unit of work instead of BTUs. They are easily confused. I'm not talking about heat. Or pressure. I'm talking about work done in a given unit time. In an engine that's the amount of force generated from combustion converted into rotational motion.

Like I said- It's been a while since I took my Physics courses. That fuel you are talking about can probably never exist, because it's BTU/h number would be based off of the amount of work it can do in a given time during combustion, which would be high due to the force of the explosion (50x as you said). So it wouldn't have a low BTU/hr number because it generates such force during combustion, and can do a lot of work.

why did this thread become a physics lesson???? lol

i don't know...

Right...BUT what I'm saying is BTU/h is calculated by using the amount of heat created, anybody remember the burning peanut in HS science. what I'm saying is, it would be more accurate to describe the power output in the same term that you would a stick of TNT.

/thread

bubba, read up
http://www.planetark.com/dailynewsst...5388/story.htm
http://domesticfuel.com/2005/09/19/e...economy-study/