In the latest tesla announcement they said:
“Paired with the new more efficient drivetrain design, Model S and Model X are now capable of achieving 200 kW on V3 Superchargers and 145 kW on V2 Superchargers."
The Renault Zoe also appears to have a connection between motor and charging speeds:
In June 2015, Renault announced the introduction of a new, smaller electric motor called the R240, manufactured at its Cléon engine plant. The new motor has the same power and torque that the Q210 unit with an extended NEDC cycle range of 240 km (150 mi). However, the Q210 would still be available as the R240 did not allow quick charging. ~ Wikipedia
Why does the drivetrain impact charging speeds?!