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Comment by dublinben | Hacker News Reader

24mph is an excruciatingly slow average speed for a 450 mile journey. No wonder they were able to be so efficient.

so, basically slower than a pro on a bicycle

nice one

Also a lot less energy efficient. They claim 171Wh per mile, that's 147 kcal per mile. On a recent 17 mile ride, I applied 591kJ (141 kcal) of work to the bicycle. So a bicycle ridden by a non-pro is almost 18x more energy-efficient than the car. (Of course more than 141 kcal of energy is required to get your muscles to do 141 kcal of work on the pedals. But not 2500 kcal worth, like the car would require. I wish a 1 hour bike ride burned 2500 calories.)

A pro, or at least someone comfortable with averaging 25mph over a long distance; given a relatively flat course, would probably require an average power output in the region of 300 watts. So even if we take the higher speed into account this works out around 12Wh/mile. ..but if we take weight into the equation; assuming the rider and his bike are on the chubby side and work out a combined 100kg - we get 0.12Wh/kilo/mile. Most of the tesla range are over 2000kg excluding passengers, so taken as a Wh/kilo/mile calculation it actually works out around slightly more than 1/3 greater efficiency at 0.086Wh/kilo/mile. Not too bad..

Of course a bicycle that is what... 1.2x human weight... is more efficient than a car that is probably ~10x human weight, when you measure it by vehicle rather than kcal per mass.

The weight of a car is not optional. If I want to move some mass between point a and point b, and I do it by car, I have no choice but to haul along that extra ~10x my weight. Measuring by kcal/mass ignores this practical reality in favour of a more precise definition of "efficiency".

Also if you're riding a bike that weights 1.2x your body weight, you have the wrong bike! Good god!

Neither 4 passengers, pile of groceries, comfortable dry seats, infotainment & air conditioning are optional on bicycle.

In other words apple to oranges comparison.

Don't know if you were kidding but I think the implication was the combined mass was 1.2x your weight. Of course even then, that's still a pretty heavy bike (I think my commuter clocks in at about 10% of my weight)

What would the pro's average speed be over the total distance? And what would an ordinary human being manage?

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