I just noticed this post about some rather clever bike-advocacy shirts at Carectomy and thought to myself "53 Miles per Burrito is a really excellent slogan...but it's also a really excellent point." The question becomes...is the human body actually more efficient than an automobile and, if so...why?
A little bit of research tells us that riding a light-weight bicycle consumes about 35 calories per mile. Walking consumes about 100 calories per mile and is, of course, considerably slower.
Driving a car ends up consuming 1,800 calories per mile. This sure makes one think twice about biofuel, doesn't it?
I try to eat about 2,000 calories per day. If that food was converted to biofuel (as most of it could, since most of it is carbohydrates) it would drive a car less than a mile. But if I use it to bike, I could go 57 miles!
So the question remains, how many miles can I extract from a burrito. Well? You may be surprised to discover this, but a Chipotle burrito with beef, beans, cheese, sour cream and guacamole, comes in at an astounding 1,300 calories. Bust a gut with one of those and you'll find enough energy to travel 37 miles. If it were gasoline instead of a burrito, those same calories wouldn't even get you a full mile.
So why is the human body so much more efficient than automobiles?
It turns out that they aren't that much more efficient. Car engines aren't superbly efficient, that's for sure. But what's much more inefficient is the fact that 95% of the net weight of a car is car...only 5% is the driver. With a bike, the equation is shifted significantly toward the weight of the driver, not the vehicle. Only 65 of the 1800 calories used to move the car are used to move the driver. The rest is used to move the doors and the roof and the airbags and the cup holders around with you.
But still, bicycling comes out on top. Our bodies turn out to be almost two times better at converting calories to motion than cars.
Sometimes, if you want to see some powerful environmental technology, you don't have to look any further than your big beefy quadriceps.