CRIMs hey? Is that what they are officially called? So although they might have reduced efficiency compared to a PM they are better at freewheeling. It was also one of the reasons they mixed the two motor types with a PM and IM, simply beacuse of the overall low power required to propel a slippery EV. As well ss the whole rare earth magnet thing and especially cost of course.So apparently as the Plaid has them the CT will have CRIMS.
Now as these are IM's at heart we are back to rotor hysteresis and copper losses. I wonder if these are responsible for the Plaids coming in at just under 400 mi and the cancellation of the Plaid plus.
Really by using hypermiling techniques whilst driving, like coasting, you can achieve better milage overall. Inertia is 100% efficient after all. Terrain mapping and preditive driving algorithms to achieve idealised momentum whilst transversing uneven terrain really does work (see Mercedes trucks). Another thing I'd like to see added is a constant power cruise control instead of constant speed.
A decade or so ago I was reading up about the different harmonics on a IM motor. At first these harmonics seem trivial, turns out they aren't. By using what they called a "chorus" ESC they were able to increase the efficiency by 3-4% not only putting them in range of a PM, but also reducing thermal loading. This meant they could use a chorus motor controller on any existing IM and increase the power output by 2-3x without any thermal issues. (Mechanical was something different)
So now I'm wondering if they're also using the same techniques together with square wire coil windings (and maybe hairpin coils) and a higher overall motor rpm (read higher peak power with even smaller motor) that requires a CF wrap to achieve near PM efficiency but with a IM.
One thing I noticed on the LR and plaid skateboard picture is that the motors all look the same size now, meaning its likely both front and rear motors are the same, with the Plaid just adding a third motor and a rearranged gearbox. I'm thinking that locking down the IM motor design to a common part across the range (incl. CT and semi) and streamlining manufacturing and costs the overall product actually improves profitability too.
At some point adding a few more battery cells to offset motor efficiency loss doesn't have a negative cost impact on range. Especially so if battery costs are appoaching $80kWh (4680s).
Theres also other areas where overall efficiency can be gained, in particular with aerodynamics, HVAC and tyres. It would be interesting to see a complete system sensitivity analysis. I think we're quickly approaching a period, probably within the next 5 years or so, where efficiency improvements will become more incremental and progressively harder to achieve.