Tesla Roadster's 98% efficient transmission nominated for innovation award

[MetroMPG]

1.5% loss per mesh. I really should think about ditching 1st and 5th then: 3% improved trans efficiency... And if I go ahead with the taller 5th for the Flea... guess what... I'll have an extra shaft I can remove gears from (though in terms of wear, it'll have unmatched gears on it).

[Daox]

I believe the gears must be engaged to actually be loosing that much. Obviously, if they are just churning oil you have additional losses.

[ALS]

When I had my 65 GTO I mostly only used first and fourth gear. I'd take first up to 3500 rpms and shift into fourth. It would drop down to 1,600-1,700 rpms. Got to love a close ratio four speed and a big V8 with lots of torque.

First gear at 5,500 rpms would take me to 55 mph. Fourth at 55 mph I would be running 2,750 rpms. Accelerating up to speed on an interstate on ramp there was no need for second or third gear. I would just hit 3,500 in first and skip to fourth and continue up to 55 mph.

That is the advantage to an electric motor also instant torque at lower rpms.
There is no need for a multi gear transmission or at least go back to a three or even two speed transmission. With a two or three speed transmission you can optimize the power to speed ratio so your not running the electric motor too slowly forcing it to pull more power than is really needed.

[jkp1187]

Wasn't Tesla trying to get a transmission with 2 forward gears to work? Did they completely give up on that?

[almightybmw]

telsa had a 2 speed to begin with, but had issues with it breaking the gear box. Thus the one speed design came second; although they wanted a one speed, implementing it by production time wasn't happening, so the "simpler" 2 speed was used as an interim.