Someone parked a Tesla up in my street last week, and it was huge. I know that cars in Europe (where I live) are generally smaller than in the U.S., but it got me thinking. Why are Teslas so big? After all, shouldn’t an electric car be smaller and lighter than a gas car?
Batteries are big, heavy, and expensive. Their power density is much lower than that of a tank of petrol, so you’d think that an electric carmaker like Tesla would want to minimize:
- The weight of the car itself
- The number of juice-sucking gadgets inside the car
To go a bit deeper into this, the problem with powering a vehicle is that it has to carry its own fuel. And as you add more fuel, it takes extra energy to move the fuel itself. NASA has called this The Tyranny of the Rocket Equation, but it also applies to any other vehicle.
A problem even NASA can’t solve
Petrol, or gasoline, holds a lot of energy for its size and weight, so we’ve never needed to bother with this equation in the past. In fact, so cheap is gas in terms of energy-storage efficiency that there’s plenty left over to generate power for air conditioning, electric chair motors, powerful stereos, heated cup holders, and other essentials.
But for electric cars, the size of the batteries is a problem. Take a look at this table of NASA data, showing the ratio of fuel to payload for various kinds of transport:
For our purposes we can disregard the flying vehicles, but you get the point. The heavier the vehicle, the more fuel it needs, which itself makes the vehicle heavier. And so on.
Clearly, then, the purpose of the Tesla isn’t to make a greener car. Instead, it’s an attempt to make electric cars cool and acceptable to a skeptical buying public. The premise is that an electric car is itself greener, just because it’s electric. In a way that’s good, like Burger King selling the Impossible Burger: Plant-based burgers become more palatable to serial meat eaters1.
Not all electric cars are green cars
Most of the problem, though, comes down to the customer. I posted the title of this article — Why are Teslas so big? — on Twitter to see what people thought.
“[C]ar buyers nowadays equate size with quality. SUVs rule,” replied journalist CJ Maillard. “Most people seem to want air-con and a full set of adjustable leather armchairs.”
Cars are getting bigger in general. Compare today’s Mini to Sir Alec Issigonis’ 1959 original. In fact, if you ever see an old Mini parked up next to a Smart car, you’ll be surprised at which is smaller.
And that’s it. To compete with modern gas-powered automobiles, an electric car needs to offer the same bells and whistles, however dumb and wasteful they are. Otherwise it will be seen as a spartan hippie-mobile like France’s Eden. And while those are pretty cool, I don’t see anyone using it to commute on the LA freeway.