700 MPG (of fat)
 

I do realize this is silly, nevertheless, humor me and pretend carbs don't exist for a minute, and that ounces/fluid ounces are the same thing.

There are 3,500 calories of fat in a pound (16 ounces).
There are 128 ounces in a gallon, and eight "pounds" in a gallon.
There are 28,000 calories in a "gallon of fat".
Assuming a (hardly agreed upon) expenditure of 40 calories per mile:

28,000 / 40 = 700 MPG

Tell your fat friends.

Uh, tell them what?

"Man, did you know you got enough fat to go from here to Mars!"

That will get me a big bequest in their will I'm sure...

Specific gravity of fat is ~0.917, so only 7.3 lbs per gallon.

How much of that fat is stuck between your ears?

I have no fat friends. Hell, I have no friends. Thanks now am I not only skinny but I'm depressed as well. Guess I'll eat a cookie or something.

Gasoline contains around 114,000 btu/gal. According to google, that converts to 28 million calories.

28 million / 3500 (calories in a pound of fat) = a lot of pounds of fat.

Good new: You're not too fat for this sport, you just have a high-capacity gas tank.

Approximately 135g of fat in the brain, but I'm trying to burn that off ASAP.

How does the energy efficiency of a human engine compare in Golden vs on the way to Leadville?

A 'calorie' of fat is actually a kilocalorie of energy. You're off by a factor of a thousand.

Edit: you also forgot to convert gallons of gas to pounds. In fact, the energy content of gasoline is right around the same for fat.

Not sure, but it's nice to know when I'm about out I can coast home in neutral.

The most prudent time to say, "TGIF"!

Yup

Holy crap! I am going to be riding for a long, long time.