Fuel Economy

Gas Mileage, MPG, is one of my pet peeves. It is a remarkably unhelpful figure since it tells nothing of a vehicles actual efficiency.


A 80,000 lb semi-truck can pull at 8 miles/gallon.

That’s 10,000lb per gallon per mile (pgpm)…

My 1999 GMC Sierra 1/2 ton truck? 16 mpg. It weighs 4,248 lbs.

That’s 265.5 lb per gallon per mile…

Why can my truck that weighs roughly 9/160th of a semi not get 160/9 of the gas mileage (142.222… miles per gallon)?

Even if my figures are horridly off that puts me in the lower range of 71MPG if I’m off by half, 35MPG if I’m off by four. I get neither.


There is a difference between performing a calculation and solving a problem. I’ve been considering the equation of a circle, . Except, you see, that’s not the entire thing. There’s a bit that we’ve dropped because it’s  zeroes (and therefore doesn’t affect our equation): . This equation contains the full information–everything that is necessary to draw and position […]