I tweeted this a few days ago:
"Gas for motorcycle: 2.855 gal, 245.9/gal, $7.02, 230.4 miles."
I later tweeted:
"Crunching the numbers, that's 80.7 mpg on the motorcycle, or 32.8 miles per dollar.
How many mp$ does your car get?"
We don't think about miles per dollar much, though I'm sure any car owner can
proudly recite their vehicle's miles per gallon statistic. But that contains a level
of indirection that makes the number less comprehensible. Who cares about mpg? Nor
does it matter that prior to May 16, my last motorcycle fill-up was April 23.
What really matters is how much it actually costs to drive the car. You don't spend
gallons, you spend dollars. Even saying it only cost me 60¢ to drive downtown and
back, as I tweeted back in April, is lost on most people, as they have no basis for
Let's instead make that figure more explicit: Miles per dollar.
As a real-life figure, let me go back to February 28, the last day I myself filled
the car's tank.
"Gas for the car: 10.53 gal, 189.9, 87 octane, $20.00, did not fill but came close."
I did not tweet the miles traveled on that tankful, but do have the information, as
I know we get 20 miles per gallon with that car. So, do the math. 10.53 gallons
times 20 mpg equals 210.6 miles, divided by 20 dollars, conveniently becomes 10.53
miles per dollar.
That then becomes a number you can wrap your mind around. Every 10 or so miles I
drive the car costs me a dollar, at least in the figures from February 28.
Of course, every situation is different. Every car is different, and the price of
gas changes daily. Today, for example, gas is 249.9¢/gallon. Same car, same amount
of gas purchased, but this time that purchase is $26.31. Do the numbers this time,
210.6 miles divided by $26.31, we get 7.98 miles per dollar. Now, every eight miles
costs me a dollar. A four-mile drive to the store costs a buck in gasoline.
Think about this in terms of a daily commute. If I drove to work, 12 miles each way,
hardly unusual for anyone in my neighborhood who works in the city, that's a 24-mile
round trip, or $4 in fuel. $20 a week. About $90/month, ad infinitum, if you did
nothing differently. It's also pretty close the the current cost of a monthly zone 1
Think also what a return to the $4 gas we were paying just a couple short years ago.
10.53 gallons would cost about $42; 210 miles of that works out to five miles per
All of this becomes irrelevant when you stop driving voluntarily. Figure out how to
get around without consuming gasoline.