Close-up Look @ the Wheel Motor powered SIM-LEI [video]

The SIM-LEI, an electric car developed by a spin-off startup at Keio University in Tokyo in collaboration with a total of 34 domestic and foreign companies, says it is on track to start mass-producing the vehicle in about 2 years.

The SIM-LEI can travel 333 kilometres (207 miles) on a single charge of it's 24.5 kWh battery, which is approx the same battery capacity as that found in the Nissan Leaf. SIM Drive said the SIM-LEI (“Leading Efficiency In-Wheel motor”) recorded an electrical power consumption of only 77Wh/km during JC-08 mode tests. (for comparison, a Nissan LEAF consumes 120Wh/km in JC-08 mode).

A brief run down on electric vehicle dynamics to explain how this vehicle achieves 77 Wh/km.

The SIM-LEI uses Direct Drive wheel motors which eliminates the 20-30% energy loss common to a typical automotive mechanical transmission system. This direct drive energy efficiency gain translates into a matching increase in brake energy regeneration potential and that potential is multiplied by the SIM-LEI being all wheel drive, meaning it collects the maximum available regenerated energy compared to a 2WD EV (70% of vehicle braking is on the front axle).

The JC-08 test represents driving in congested city traffic, including idling periods and frequently alternating acceleration and deceleration, providing plentiful opportunity for brake regeneration.

The JC08 is conducted on a chassis dynamometer so does not test the SIM-LEI's aerodynamics which at Cd of 0.19 is the same as the tear drop shaped GM EV1 and is significantly better than the 0.28 Cd achieved by the Volt or Leaf. When you consider drag (and resulting energy loss due to aero friction) is proportional to the square of speed you begin to understand the SIM-LEI has been designed from the ground up to be a seriously energy efficient EV.

Consider that if SIM-Drive produced an EV with range equal to the Nissan Leaf it would require a battery pack with approx half the capacity = potentially halving the cost of the most expensive component in the vehicle.

The SIM-LEI is equipped with a 65kW / 700 Nm Outer Rotor BLDC PM Wheel Motor in each wheel (260kW / 2800 Nm total), an in-dash 19-inch display, and a set of side-view cameras.