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ISX

BTU/Gallon Neat!

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ISX

Stumpled upon a huge chart of BTU stuff on wikipedia. So I made it into something neat.

BTU/Unit--Means how many BTU are in every unit, as in 1 gallon of the fuel or 1kw of electricity...

To Equal Diesel--Means how far you could get on other fuels if they took the same 6475 BTU/mile that my cummins uses. This means a gasser should be getting 17.6MPG if it were the same efficiency.

Miles--Means how many miles you could go if it were the same burn rate as I burn diesel. What I did here was took BTU/20[mpg] and got a base number (6475) which tells me it takes 6475 BTU's to go a mile. So then I used that baseline to use against everything else so the base gas 114,000/6475=1.14 Gallons. That means it would take 1.14 Gallons of gas to go a 20 miles if it takes 6475 BTU to go each mile.

Cost/Unit--Means cost per unit based on the national averages I could find. (only found them on diesel, e85, reg unleaded, so the rest is from around here or other users).

Cost to Equal Diesel--Means the cost of the fuel you will need to be at the BTU content of a gallon of diesel.

1000 Miles--Means the cost it will take to go 1000 miles at the mileage of each fuel and 6475BTU/mile.

The kw/h is pretty neat. Means it takes 37.94Kw/Hr to equal a gallon of diesel. At 7 cents a kw/hr or so, that actually ends up being close to what diesel is a gallon. $2.65

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KOYOTE

well i read this earlier and came back to it a few hours later and read it slowly again and i am glad to see no real responses. this leads me to believe i am not totally retarded by not having a good comprehension of this chart, but none the less it looks cool and i'm sure theres people here smarter than me that will enjoy it.:thumbup2:

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guesswho512

it just goes to show you that the CNG that Chesapeake is trying to push on us isn't such an awesome fuel! sure you only pay $1.49. and where are you going to fill up at? hydrogen may be zero emissions, but its low on power and the emissions made to "making" hydrogen fuel can be even higher. no simple solutions...

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flman

Thanks, I posted this in another forum on the never ending debate that gassers are better then diesel because of what GM did back in the 80s :soap:

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ISX

Alright I updated the first thread. Now you can see prices based on what I can find on averages or around here or from guesswho.

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KOYOTE

so as i see it this chart neglects the difference in fuel efficiency and burn rate of these fuels and how that would change the differance in cost per mile?

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ISX

so as i see it this chart neglects the difference in fuel efficiency and burn rate of these fuels and how that would change the differance in cost per mile?

Yeah. Everything is based on the BTU per Mile, of a gallon of diesel fuel.. I put in 20MPG and the BTU content of a gallon of diesel is 129,500. So if you take 129,500 divided by 20, you get 6475. This means it took 6475 BTU's to get me 1 mile. I based ALL of the calculations off of that 6475 base. .

So to get 17.62 miles for gasoline (the "Miles" column), I used gasoline's BTU content (114,100) and divided it by 6475 to see how many miles I could get out of that BTU content. Since 114,100 is less than 129,500, it is obvious why I went 2.38 miles less. This is also a measure of what every fuel should be getting MPG-wise since it is based on one gallon, hence "miles per gallon". So the gasser with the same efficiency as a 20MPG diesel, should be getting 17.62MPG.

Now the "To Equal Diesel" part is how many gallons it would take to MATCH the energy content of a gallon of diesel fuel. So if diesel fuel has 129,500BTU, and gasoline only has 114,100BTU, I would have to use more gas to get the same BTU as diesel fuel. So you take 129,500 and divide it by 114,100 and get 1.13. So I would have to burn 1.13 gallons of gasoline for it to end up at the same BTU content as diesel fuel. All of the numbers use 129,500 as the base index. So if something were to have 150,000BTU per gallon, it would only take 0.86 gallons to match a gallon of diesel. That is how that whole column works.

"Cost/Unit" is just how much it is a gallon, so whatever it says on the fuel station sign.

"Cost to Equal Diesel" uses the gallons it takes to equal diesel's BTU content, like gasoline uses 1.13 gallons, so you take 1.13 and multiply it by the price of gas $2.742 (national average), and you find out how much you are really paying for the same energy content of a gallon of diesel. So as we can see, even though diesel is more expensive, having to buy more gasoline to get the same BTU as diesel ends up costing you MORE. You can see E85 is very cheap, but when you factor BTU in, you can see how much your REALLY paying for the same amount of energy.

"1000 Miles" means how much it costs to go 1000 miles. I took 1000 divided by whatever was in the "Miles" column and that gave me a gallon amount. Gallons multiplied by the fuel's "Unit/Cost" gave me how much it would cost to use that many gallons. Therefore giving me the price of going 1000 miles on each fuel.

Got it?

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guesswho512

so the best analogy is a multi-fuel motor? you have to read the chart as different fuel, same motor, to take out the 100s of variables. obviously, a motor designed for a certain fuel will be tailored to get the most power from that specific fuel(ie compression ratio, ignition type, etc)i love that your list includes electricity and hydrogen. notice the really low numbers. goes to show you exactly why carbon is king!

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ISX

so the best analogy is a multi-fuel motor? you have to read the chart as different fuel, same motor, to take out the 100s of variables. obviously, a motor designed for a certain fuel will be tailored to get the most power from that specific fuel(ie compression ratio, ignition type, etc) i love that your list includes electricity and hydrogen. notice the really low numbers. goes to show you exactly why carbon is king!

Exactly how the chart is! All fuels would be running exactly the same efficiency and everything.. Obviously real world statistics are not the same. I think gassers like the new 6.0 v8 in chevys can hit 17-18mpg, but then look at the power and we have to start the statistics all over again :lol: They just aren't even in the same league. As for hydrogen and electricity, not sure on hydrogen but you can see electricity is comparable to a gallon of diesel (cost for cost). Electricity is made through extremely efficient means, but now how do we transfer that energy to something that moves? Ok we got hybrids, but then we are back to making the power with a gasser or diesel. The efficiency I am talking about is through steam from burning coal and the steam driving turbines. If we could harness their power and use it on the road, we could save hundreds. You have to remember that 6475 BTU per mile for a diesel is also equating the 2/3 lost in the radiator and exhaust which electric motors do not see. So they might actually use 4000BTU per mile.. But unless we have an extension cord from the power company, we are still tethered to gasser or diesel efficiency to charge the batteries. If anyone can get me a price on any other units I could add that in..

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