Most people think the Spark EV drivetrain will be used in the Bolt. Personally I don't think so. The Bolt will be bigger and weigh a lot more, so the puny horsepower output of Spark EV drivetrain in my opinion is too low. Rather than develop a more powerful single motor drivetrain, I think it makes more sense to use the Voltec propulsion system because it already produces adequate torque and horsepower and the two motor design is more efficient at highway speeds than the Spark's.
GM could also possibly change the gearing in the Spark motor assembly thereby reducing the low-end torque
while improving its highway speeds and still maintain the simplicity of single motor design and cost. The HP
(130 - 97kW) of the Spark motor is adequate for the size and weight of the proposed Bolt.
#1 Leaf SL MY 9/13: 76K miles, 47 Ahrs, 5.0 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 8.5K miles, 115 Ahrs, 5.2 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F