nader wrote:I understand the whole 4-9000rpm motor efficiency thing. In this case it's how much of that electricity is turned into mechanical motion. Are you guys telling me that if I were to put this motor on a dyno and run it at 4,000 rpm and then at 9,000rpm that it's consuming the same amount of electricity? Conventional wisdom tells me that is not the case. Please school me.
Side note: Because of this motor efficiency and lack of transmission I am guessing that drivetrain losses are much lower than a traditional ICEV.
A good (if Tesla-centric) general discussion, with illustrative graphics, of BEV efficiency compared to ICE, hybrid, and fuel cell Vehicles, is here:
The LEAF is consuming much more than 9/4 times the electricity on the road running at 9,000 vs 4,000 rpm, but this is primarily due to the effects of wind resistance at greater speed.
Looking at the Tesla power consumption chart, you can see that each rotation of the wheels on the dyno actually takes less power, at higher engine rpms, corresponding to road speeds up to at least 70 mph. Given the LEAF drive train efficiency chart, it would also appear to be true, up to dyno (wheel speed w/o wind resistance) speeds of about 70 mph.
Interestingly, Tesla originally planned a 2 speed, but later decided it was easier just to rev the damn thing to 14,000 RPM, according to: