...To say that Tesla misrepresented their car by claiming 691 motor hp is simply incorrect. The first thing that I look at when looking at a complex system that has few inbuilt motors that make such system perform any work, is to look at motors spec. That spec is one of the most informative metrics of the system, as it determines the system performance in various scenarios.
Well it seems to me that if someone is looking at electric motor 'specs', then for ac induction motors the specs would be as stipulated by the IEC (International Electrotechnical Commission) Standard 60034. For example, Part 1: Rating and Performance, defines the duty cycle ratings on a scale from S1 to S10, which relates the operational time and load for which a motor can run to reach thermal equilibrium at a specified maximum temperature. S1 is continuous duty, S2 is short-time, S3 is intermittent periodic duty, etc.
When a rated quantity (output power, voltage, speed, torque) may assume several values or vary within limits, then the rating shall be stated at these values or limits. The motor will have the applicable ratings listed on the label.
Another electric motor standard is available from the Institute of Electical and Electronics Engineers, IEEE Std 112-2004, IEEE Standard Test Procedure for Polyphase Induction Motors and Generators, which provides instructions for conducting and reporting the more generally applicable and acceptable tests used to determine the performance and characteristics of polyphase (mostly 3-phase) induction motors and generators.
Of course if TMC were selling motors, then they would be required to have a motor rating label just like everyone else, but obviously they don't sell motors—-they sell cars.
So it makes you wonder why they tried to use some ECE automotive standard to express electric motor performance, when these other standards already existed solely for rating electric motors?
- - - Updated - - -
Achhhh! The motor produces the power. Please look a v's hp/torque charts.
No the motor is commanded to produce torque, this is covered and clearly explained in the patent describing the AWD control system. The output power is calculated based upon this torque and the resulting speed that the motor can reach against the sum of the loads.
To move a 5000 lb vehicle from 0 to 60 in 3.2 sec only requires an output power of 342 hp before losses.
Add in friction, aero loads and losses of energy-conversion and the number goes up to 463 hp for a tesla vs 707 hp for a hellcat vs 691 hp for a McLaren F1. So the tesla wins by being the most efficient at converting energy against real loads as measured by the real output power.
--updated with more mind-numbing technical details--
The rotational force or torque produced by a three phase induction motor is a function of the magnetic flux in the stator poles, the rotor current, and the cosine of the phase angle between the rotor emf and rotor current.
The gory maths and details can easily be found on the web, but in simplest terms it boils down such that the torque is proportional to the stator current squared. So to double the torque requires 4 times more current.
The speed that a motor runs is determined by the balance between the torque generated by the current, and the external load forces against which the motor is trying to overcome. When the torque exceeds the loads, acceleration occurs.
The mechanical output power can then be calculated by multiplication of the applied torque times the resulting speed.