Car Analogy

You forgot to wish the post you quoted Happy Birthday. It'll be 19 in a couple days...

Slowcrash_101

Nope octane rating is a resistance to ignitability. The energy content is roughly the same for 87 and 93, 93 takes more energy to ignite. Which reduces the likelihood of uncontrolled detonation.

Carbon is not an oxidizer, oxygen and hydrogen are, those are the explody bits in fuel. Particularly the reactive oxygen species like peroxide or hydroxides.

By breaking carbon bonds(which require energy(ie compression + spark)) you release the radical species of hydrogen and oxygen which leads to the energy release known as combustion.

Much like in social life, breaking bonds require energy, we feel low when we lose a friend, and forming bonds release energy. How energetic we feel when we find someone to love. Chemistry works the same way

Adding carbon bonds require more energy to break them in order to release the kraken of radicals. The radicals release their energy by forming stable bonds with carbon.

cosmomiller

I went through and read all the posts. This is the reason fuel for larger aircraft, usually commercial and military, are measured in pounds. Fuel flow, fuel quantity, etc are all in pounds. When you are refueled you receive documentation from the person responsible of the actual metered amount, in liters or gallons, AND the fuel density. It changes all the time. Then you can calculate the pounds received. You also get the type of fuel and the freezing point (important flying over the North Pole).

Nil-S2k

We are assuming he needs the weight...on earth....

cosmomiller

Yes indeed. The point is that distilled fuel, unlike water, can vary in density. That is why you sometimes see (usually at Costco Gas stations) a sticker or sign indicating that the amount of fuel delivered can vary due to density changes and the actual amount of energy supplied can also not be constant from time to time.

Nil-S2k

This is, of course, why I only pump gas on high barometric pressure days. Higher fuel density.

engifineer

Sea level or peak of Mt Everest? Or how about at the top of a large mountain on the equator where the effect of centripetal force plays into it more? Or how about a large mountain on the N or S pole where centripetal force does NOT play into it? Man ... we could be off a fraction of a percent here and not even know it... how much fuel is in my car again?

Nil-S2k

But if the fuel weighs the same as a duck....

engifineer

Well if it weighs the same as a duck then it must be a witch ... and we burn it anyways!

Nil-S2k

Not to mention.....fuel floats on water like witches, ducks and wood....