I know electric cars don’t need multiple gears, but wouldn’t they benefit from them in anyway at high speed for example?

Question

I know electric cars don’t need multiple gears, but wouldn’t they benefit from them in anyway at high speed for example?

In: Technology

Answer 1

No. An internal combustion engine has low torque and low efficiency at low RPMs and at high RPMs. Gearing is needed to keep it in the sweet spot so the engine does not bog down.

An electric motor has it’s highest torque at low RPMs and it’s highest efficiency somewhere around 70% (ballpark) of it’s highest RPMs. Once you hit the “highest” RPMs, you can do additional electrical/mathematical magic that sacrifices efficiency for more RPMs.

The problem with gearing is that each gear-pass is maybe 98% efficient if you are lucky. So introducing any gearing at all reduces an electric motor’s efficiency more than what is gained by doing the electrical/mathematical magic when it is needed in extreme and uncommon scenarios.