Technology

PS

One issue I hadn’t thought of is putting traditional brakes (which generate a ton of heat) right next to the motors. Again, we're just asking for mechanical issues here, and we’re ballooning unsprung mass to mitigate it, especially in heavier cars that take a lot to stop.

The entire floor pan could just be one thin battery, and everything above it could be passenger and storage space.

This seems like a minor thing, but the control electronics for the motors takes up a nontrivial amount of space. So do “traditional” subsystems like hydraulics, climate control, or an old fashioned car battery (which often exists in parallel to the EV drivetrain).

Theres also safety to consider. A traditional sedan “hood,” even a small one, is easier on standing pedestrians, so it hits their legs and they flop on top, instead of slamming them like a wall (as a bus-like front would).

That's how EVs started! Sorta.

This is from a Porsche in 1900:

And some 2000s EVs tried it. But it's impractical.

• It increases unsprung weight, e.g. weight not cushioned by suspension. Bad for ride/handling/steering feel.

• All that vibration is HARD on the motor. Read: unreliable.

• Motor is more exposed to temperature/dust. Again, reliability.

In reality, a decent suspension needs a lot of room under the body anyway. An axle to get the motor in the body is dirt cheap on the rear, and still pretty cheap on the front, and you could just mount this thing sideways to make it flat...

That would be a lot of unsprung weight.

Handling and ride quality are dramatically and negatively impacted by every bit of weight that is not held up by the suspension. That's why higher performance cars will have lightweight wheels. Rather than steel wheels you see on lower performance cars.

It's better to just put all the heavy drive components inboard on the chassis and run drive shafts to the wheels.

You see motors in the hubs of bicycles, because they really don't go that fast. So even if the bike has a suspension, it's not that big of a deal. Motorcycles on the other hand would need to keep any heavy parts inboard.

Aptera wanted to do this with their flagship Solar Electric Vehicle (SEV).

IIRC, they switched to an outwheel motor because of the weight the inwheel motors added to the wheels. Could be wrong tho

Hub motors are a party trick. They will never reach mass market in a car.

This is already pretty close to how many EVs are designed.

Except for the fact that that much power would need massive batteries. So your thin small battery would be dead the first time you mashed the peddle to the floor