So if you could halve the weight and the CDA of the tesla, you could have similiar performance with half the motor and batteries, and no gears, I think
If you could live with 1/5th of the 230 mile range, you could maybe use 1/5 of the battery pack (if the remaining batteries can still deliver the performance).
edit 683 of those li-ion batteries would be like 70 lbs!, the tesla is carrying about 700lbs of them, there is an easy weight (and cost) cut there.
more specs on that battery:
Specifications: Nominal Voltage :Average 3.7 V Nominal Capacity :2350mAh, Minimum 2300mAh Max. Charging current: 2.4A Max. Max. Discharging current: 4.6 A max. Dimensions: Diameter 18.3 mm (Max 18.4), Height: 64.9 mm (Max 65.1) Weight : 46.5 g (1.64 oz) Internal Impedance: Internal Impedance: less or equal to 90 mohm (with PTC) Cycle Performance: 80% of initial capacity at 300 cycles
So that 7 strings at 400v would be 756 batteries. Which could deliver 32.2 amps @ 400volts or ~17HP. Scaled up that would "only" be 170 HP so I think that tesla either has better batteries, is over pushing them a bit, or has more motor than the batteries can fully utilize.