Wednesday, 21 September 2011

900 mpg? You've got to be kidding...?!

As oil supplies dwindle and concerns over climate change grow, the search for energy-efficient transport solutions has never been more crucial.

Apparently the average modern car manages just under 38mpg (miles per gallon). Not bad, and nearly twice what gas-guzzling cars were doing 40 years ago, pre oil worries...

Meanwhile, a Toyota Prius ekes out 65mpg and VW has announced plans for a car that will break the 100mpg barrier by 2020.

Factoring in passengers (but ignoring additional weight), that would mean an approximate per-passenger-mpg of 400.

Impressive stuff.

But a mode of transport has existed since the late 19th Century that can propel a passenger over considerable distances at an incredibly frugal 900mpg: the bicycle...

38 mpg vs 900 mpg
The maths behind that calculation are pretty simple.

Petrol contains approximately 31,000 kcal (Calories) per gallon. Of course humans can't consume petrol, but based on the equivalent Calories, here are a few interesting comparisons:

Walking - 360 mpg
Running - 300 mpg
Bus - 330 mpg per passenger*
Passenger aircraft - 49 mpg per passenger*
QE2 - 16.7 mpg per passenger*

* all figures are approximate and assume full occupancy of the vehicle, which is rarely the case - a detailed study of a Californian commuter bus route found that on average only 9 of the 55 seats were taken, one-in-six, which dramatically reduces the per passenger-mpg.

Compared to that, cycling is amazingly efficient!

And when you consider that the average speed of traffic in central London is 10 mph - the same it was over a century ago - that makes cycling a seriously economical and practical alternative to road transport.

So that's one fewer reason not to cycle...

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