TESLA.ROCKS

Tesla’s latest in-house electric motors represent the cutting edge of EV powertrain engineering. This report compares the Model S Plaid tri-motor system and the Model 3 motor(s), detailing their architecture, electromagnetic design, materials, cooling, and control electronics. We also benchmark Tesla’s motor technology against other performance EVs like the Porsche Taycan, Lucid Air, and Rimac Nevera. The goal is an engineering-focused understanding of how Tesla achieves extraordinary torque, speed, and efficiency in these motors, with citations from patents, teardowns, and technical analyses.

1. Motor Architecture and Design Overview

(This Is Tesla Model S Plaid’s Drive Unit) Figure 1: The Tesla Model S Plaid drive unit, integrating a high-speed permanent magnet motor (inside the housing), inverter, and single-speed reduction gearbox in a compact package. The Plaid’s carbon-sleeved rotor design enables extreme RPM operation for ~200 mph top speed without a multi-speed transmission.

Model S Plaid – Tri-Motor, Carbon-Sleeved Rotors: The Model S Plaid introduced a three-motor AWD setup (one front, two independent rear motors) with all-new permanent-magnet synchronous reluctance motors (PMSRM). Each motor is small and light (~45 kg for the core motor) yet extraordinarily powerful (Watch Dissection Of Tesla Model S Plaid Front Drive Unit) (Watch Dissection Of Tesla Model S Plaid Front Drive Unit). Tesla’s principal motor innovation here is the carbon-fiber sleeved rotor, used for the first time in a production EV (This Is Tesla Model S Plaid’s Drive Unit). In this design, high-strength carbon fiber wrap is wound around the rotor to contain the magnets against centrifugal forces at very high rotational speeds. Elon Musk noted that achieving a carbon-wrapped rotor was “extremely difficult” because carbon and copper (the motor’s metal components) have very different thermal expansion rates – the rotor must be wound under extremely high tension to ensure a tight fit across all operating temperatures (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping) (This Is Tesla Model S Plaid’s Drive Unit). The payoff is a rotor that can safely spin at 20,000+ rpm, enabling a single-speed transmission from 0–200 mph (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). By holding the rotor intact at insane RPM, the carbon sleeve maintains a very tight air-gap (clearance between rotor and stator) even at high speed, which is critical for efficiency and torque (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). The Plaid motors are permanent magnet type (not induction) for high power density, yet Tesla was able to eliminate a two-speed gearbox (which Porsche uses) by pushing motor RPM limits. The dual rear motors each drive one wheel (no mechanical diff), allowing torque vectoring for improved traction and handling.

Model 3 – AC Induction + Permanent Magnet (Dual Motor AWD): Tesla’s Model 3 (2017+) introduced a major architectural shift: the use of a permanent magnet synchronous motor in place of the AC induction motors that powered earlier Model S/X. Tesla’s principal motor designer, Konstantinos Laskaris, explained that for the Model 3’s desired performance and range, a permanent magnet machine “better solved our cost minimization function…and was optimal for the range and performance target” (Tesla motor designer explains Model 3’s transition to permanent magnet motor | Electrek) (Tesla motor designer explains Model 3’s transition to permanent magnet motor | Electrek). The Model 3 Rear-Wheel-Drive version uses a single interior permanent magnet motor on the rear axle. The Dual Motor AWD versions cleverly combine two different motor types: a permanent magnet motor in back for high efficiency and torque at low-to-medium speeds, and an AC induction motor in front optimized for freewheeling at cruise and extra power at high speeds (Two Types of Tesla Model 3 Motors – Lammotor) (Two Types of Tesla Model 3 Motors: Everything You Need to Know). This dual design lets the car use the rear PM motor most of the time (for superior efficiency since magnets provide “free” excitation field (Tesla motor designer explains Model 3’s transition to permanent magnet motor | Electrek)) and engage the front induction motor as needed for performance or at highway speeds (induction motors have no permanent magnets, so they impose minimal drag when not in use and can be completely de-energized) (In a AWD Tesla Model 3, why is the front and back motor different?). For example, the Model 3 Performance has a PM rear motor and an induction front motor, yielding a total output around 335 kW and 559 Nm (Two Types of Tesla Model 3 Motors: Everything You Need to Know). In contrast, the Model S Plaid uses three PMSRM motors (no induction motor) – Tesla applied their new high-RPM PM motor tech to all Plaid drive units. By using three smaller high-power motors, the Plaid can output up to ~760 kW (1020 hp) combined without overtaxing any single unit (Watch Dissection Of Tesla Model S Plaid Front Drive Unit). Each Plaid motor’s architecture is essentially an evolution of the Model 3’s rear IPM motor (“Raven” drive unit) upgraded with the carbon sleeve to handle the much higher rotational speed and power (Watch Dissection Of Tesla Model S Plaid Front Drive Unit).

Optimizing for Torque, Speed, and Efficiency: Both motor designs (Plaid and Model 3) are three-phase AC synchronous machines, but Tesla optimizes them for different goals. The Model 3’s IPM motor is designed for an excellent blend of efficiency and decent performance in a smaller package, aiding the Model 3’s range. It provides strong torque off-the-line and efficient cruising. The Plaid’s motors take it to the next level – they prioritize power density and top speed: the carbon-sleeved PM rotors allow sustaining torque at very high RPM without the motor self-destructing (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). This enables the Plaid to achieve supercar acceleration and a 200 mph top end with a single speed gear. The trade-off is complexity in manufacturing (as discussed later) and reliance on advanced thermal management to sustain such output. Tesla’s switch from induction to permanent magnet in these latest designs also boosts efficiency: PM machines have “pre-excitation” from magnets, reducing the need for extra current to magnetize the rotor (Tesla motor designer explains Model 3’s transition to permanent magnet motor | Electrek), which yields higher efficiency especially under partial load. Induction motors, however, have the advantage of perfect flux control (no fixed magnets), so Tesla still deploys them when their benefits outweigh the downsides (e.g. front motor that can idle with zero torque drag (In a AWD Tesla Model 3, why is the front and back motor different?)). In summary, the Model 3 and Model S Plaid motors share a common DNA (both use internal permanent magnets in the rotors for primary drive), but the Plaid innovates further with its tri-motor layout and carbon-wrapped rotors to push the performance envelope beyond what the Model 3’s motors can do.

2. Electromagnetic Design and Operation Principles

Permanent Magnet Synchronous Reluctance Motor (PMSRM) Fundamentals: Tesla’s motors in the Model 3 and Plaid are a form of interior permanent magnet (IPM) synchronous AC motors that also leverage reluctance torque – essentially PM-assisted synchronous reluctance machines. In these motors, a series of high-strength NdFeB permanent magnets are embedded within the steel rotor. When the 3-phase stator windings are energized with alternating currents (typically using a sinusoidal or vector-controlled waveform), a rotating magnetic field is produced in the stator. The rotor’s magnets “lock” onto this rotating field, causing the rotor to spin in sync with the stator field (hence “synchronous” motor). Because the magnets provide a constant magnetic flux, they generate torque without needing rotor current (unlike induction designs). Additionally, Tesla’s rotor geometry is salient – meaning the rotor has preferred magnetic axes due to its iron and air/magnet pocket structure. This introduces reluctance torque: the rotor will experience a torque trying to align its minimum-reluctance axis with the stator field. By arranging magnets in a V shape inside the rotor (as hinted by Tesla’s patent drawings (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents)), the design achieves both magnet torque and reluctance torque. The total output torque is the sum of the magnetic torque (from attraction/repulsion between stator field and rotor magnets) and reluctance torque (from the rotor’s tendency to align its salient iron poles with the stator field). Tesla can tune the relative contribution by adjusting the current phase angle (also known as Id–Iq vector control): at some advance angle, you get an optimal mix. In fact, simulations of the Model 3’s IPM motor show separate curves for magnet torque vs. reluctance torque – the reluctance component contributes substantially and can be optimized via current phase advance ().

Magnetic Field Generation and Torque Ripple Mitigation: A well-known challenge with reluctance-based designs is torque ripple (fluctuations in torque as the rotor turns, due to variations in magnetic reluctance and cogging between teeth and magnets). Early switched reluctance motors (with no magnets) had severe torque ripple and noise (Tesla Model 3 Motor — Everything I’ve Been Able To Learn About It (Welcome To The Machine) – CleanTechnica). Tesla’s approach of embedding permanent magnets helps to smooth this out. Research has shown that inserting rare-earth magnets into a reluctance motor can significantly smooth the torque curve, eliminating much of the cogging-related ripple (Tesla Model 3 Motor — Everything I’ve Been Able To Learn About It (Welcome To The Machine) – CleanTechnica). The magnets provide a more continuous magnetic field that reduces the abrupt changes in reluctance seen by the stator. Moreover, Tesla likely employs clever engineering in the motor construction to minimize ripple and noise: for example, slight skewing of either the stator laminations or rotor magnet placement so that not all teeth align simultaneously, and using specific slot/pole number combinations that inherently reduce harmonic content in torque. According to one analysis, Tesla’s motors might use fractional slot windings and sectioned rotor segments that are offset, as even the Cybertruck’s motor sections are said to be slightly offset to reduce ripple and vibration (Charged EVs | Tesla’s top motor engineer talks about designing a …). Additionally, software-based control plays a role: the inverter can inject current harmonics or adjust the current waveform on-the-fly to counter any residual torque ripple or acoustic noise (Tesla is known for using software to improve performance continuously via updates). All these measures result in a very smooth torque delivery despite the highly salient motor design.

AC Induction Operation (in Model 3 front motor): The front motor in dual-motor Model 3 (and older Model S) is an AC induction machine. Induction motors have no permanent magnets – instead, the rotor is typically a “squirrel cage” made of conductive bars (copper or aluminum) and iron laminations. When AC currents flow in the stator, a rotating magnetic field induces currents in the rotor bars (by electromagnetic induction). These rotor currents create their own magnetic field which then lags behind the stator field, resulting in a torque that drags the rotor around. Tesla’s induction rotors are high-performance as well – the Model S used a copper rotor (better conductivity than aluminum, but harder to cast) for lower resistance and higher torque (Tesla Model 3 Motor — Everything I’ve Been Able To Learn About It (Welcome To The Machine) – CleanTechnica). Induction motors naturally have no torque when the stator field is not energized (the rotor field vanishes when current is off), which is why Tesla pairs one with a PM motor: the induction unit can freewheel with essentially zero magnetic drag when not needed (In a AWD Tesla Model 3, why is the front and back motor different?). However, induction rotors do heat up from the I²R losses in the rotor and typically are slightly less efficient at light loads, as they require slip and magnetizing current. By blending both types, Tesla can exploit the best characteristics of each.

Efficiency Optimization: Tesla’s electromagnetic design choices heavily target efficiency across the operating range. The use of interior magnets means the motors have a high base efficiency thanks to the constant magnet flux, especially during gentle driving where an induction motor would waste energy magnetizing the rotor. In fact, by switching from an induction motor in Model S to a PM motor in Model 3, Tesla improved range by roughly 10% for the same battery, due to higher efficiency in most driving regimes (Tesla switches to permanent magnet reluctance motors and sees …). The motor geometry (V-shaped buried magnets and reluctance gaps) is optimized to give a very high flux linkage while minimizing leakage and magnet usage. The air gap is kept as small as manufacturing tolerances allow, since a smaller gap gives a stronger magnetic coupling (Plaid’s carbon sleeve helps maintain a tight gap even at high RPM when centrifugal force could normally cause rotor expansion) (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). To reduce losses, Tesla uses thin silicon steel laminations in the stator and rotor to reduce eddy current losses in the iron. The high electrical frequency at 20k rpm (for example, a 6-pole pair motor at 20k rpm is 1000 Hz electrical) could cause significant core losses; thin laminations and high-grade steel (with high silicon content to reduce hysteresis loss) mitigate this. They also likely segment the magnets inside the rotor into smaller pieces. A teardown of the Model 3’s IPM rotor showed that the magnet was segmented (not one big piece), which “helps reduce the eddy current thus self-heating of the magnets” (). By breaking the magnets into smaller sections, circulating currents within the magnet material are reduced when the rotor is rotating through the stator’s AC field. This is crucial at high RPM to prevent magnet overheating. The Plaid’s rotor, with its carbon fiber sleeve, also likely uses segmented magnets or embedded pole pieces that both improve performance and facilitate the wrapping process (Tesla’s patent mentions pole pieces and magnets held in a fixture during winding (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents) (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents)). Lastly, Tesla optimizes efficiency through field-weakening control at high speeds. Once the motor reaches its base speed (where back-EMF equals supply voltage), the inverter will advance the current phase angle to produce a negative d-axis component (in opposition to the magnet field), effectively weakening the net field so the motor can spin faster without hitting voltage limits. This allows the motor to go well beyond the nominal RPM at the cost of using some energy to counteract the magnets. Tesla’s control software precisely manages this field-weakening region to extend the speed range to ~20k rpm while minimizing extra losses, giving the Plaid and Model 3 motors a very wide operating envelope (strong low-end torque and very high top speed capability).

3. Materials and Manufacturing Techniques

Active Materials – Copper, Steel, Magnets: The primary materials inside Tesla’s motors are high-grade copper conductors, electrical steel laminations, and rare-earth magnet alloys. The stator windings use copper for its excellent electrical conductivity. Tesla initially used traditional round-wire windings, densely packed in the stator slots. More recently, they have started shifting to rectangular cross-section copper wire (hairpin windings) to increase slot fill. A flat-wire (hairpin) stator can achieve about a 20–25% higher slot fill factor than round wire and improves thermal contact (Two Types of Tesla Model 3 Motors: Everything You Need to Know). (Porsche, for example, reports ~70% fill with hairpins vs ~45% with conventional windings (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS).) Higher fill means lower resistance and thus lower copper losses (which account for a large portion of motor losses). According to one source, Tesla’s China-built Model Y rear motor adopted a flat-wire hairpin design, boosting peak power from ~202 kW to 220 kW and torque from 404 Nm to 440 Nm with the same motor size (Two Types of Tesla Model 3 Motors: Everything You Need to Know) (Two Types of Tesla Model 3 Motors: Everything You Need to Know). We can expect the Model 3 to follow with flat-wire windings in newer revisions, further reducing I²R losses and heat. The stator and rotor laminations are made of silicon steel – an iron alloy with a few percent silicon to reduce magnetic hysteresis losses. These laminations are very thin (on the order of 0.3 mm or less) and are laser-cut or stamped and stacked. Thin laminations with insulation between them prevent eddy currents from circulating within the iron as the magnetic field changes.

The rotor of the Model 3/Plaid motors contains the NdFeB permanent magnets, which are a Neodymium-Iron-Boron alloy usually doped with dysprosium or terbium for high-temperature performance (to resist demagnetization at temps up to ~180°C). These magnets are likely of the high “N-grade” (e.g., N48H or higher) and are segmental – instead of one large magnet per pole, multiple smaller magnet pieces are used, both for manufacturing ease and to reduce losses (). They are mounted inside the rotor in cavities formed by the steel laminations and additional iron pieces (as described in Tesla’s patent, there are central lamination stacks and separate pole pieces that clamp the magnets in a V-shape (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents) (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents)). The rotor’s structural shell in the Plaid motor is carbon fiber, an advanced composite. Carbon fiber has extremely high tensile strength and low weight, ideal for containing the rotor at 20k rpm. However, it’s an insulator thermally and electrically, which poses manufacturing challenges. We will discuss cooling implications later, but Tesla had to design a special process to wrap the carbon sleeve with precise tension and curing. Musk noted they built a new machine to do this rotor wrapping at high tension (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping) (This Is Tesla Model S Plaid’s Drive Unit). The adhesives and resins used are also critical: the carbon fibers are likely impregnated with high-strength epoxy. The magnets themselves and the rotor steel must be bonded well to not shift under massive centrifugal force.

Manufacturing and Construction: Building these motors is an impressive manufacturing feat. In the Model 3’s IPM motor, Tesla uses a single-barrier V-shaped magnet IPM design (as noted by outside analyses) – this is simpler and cheaper than multi-layer magnet designs, but still effective and easier to assemble. The rotor lamination stack, magnets, and pole pieces are assembled and then the whole rotor is wrapped. The carbon-fiber overwrap process (for Plaid) is described in the patent: the rotor is placed on a rotating machine, and a resin-coated carbon fiber filament is wound around at high tension in multiple layers until a specified thickness is reached (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents) (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents). Achieving uniform tension is vital so that when the resin cures, the sleeve applies an even compressive force on the rotor. The patent indicates various materials could be used (carbon, fiberglass, PEEK, etc.) (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents), but Tesla selected carbon fiber likely for its unparalleled specific strength. One challenge is the differential thermal expansion: steel and copper expand much more than carbon fiber when heated. The quote from Musk – “carbon and copper have very different rates of thermal expansion. To have a carbon-coated rotor, you need to wrap it at extremely high intensity” – highlights that the carbon sleeve must be extremely tight at room temperature so that even when the rotor’s metal parts heat up and expand, the carbon fiber (which expands less) still retains them firmly (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). This ensures the assembly doesn’t loosen at operating temperature. Tesla’s achievement here is notable; as Musk said, “as far as we know, this is the first time there has been a production electric motor with a carbon-coated rotor” (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping).

On the stator side, Tesla likely employs computerized winding insertion machines (for round wire stators) or hairpin welding techniques (for flat wire stators). The stator windings are then vacuum impregnated with epoxy resin. This resin fill binds the wires together (reducing movement and vibration), provides electrical insulation, and enhances thermal conduction from copper to the steel laminations. We see evidence of this in teardown images – the stator end-turns are often coated and secured with resin and fiber lacing (see Figure 3 in MotorXP’s analysis showing tied windings) (). After assembly, each motor is precisely balanced and tested. The Plaid’s rotor in particular must be finely balanced; any slight asymmetry at 20k rpm could cause vibration or failure. It’s impressive that the entire Plaid drive unit (motor + inverter + gearbox) is only ~95 kg yet delivers ~250 kW per motor (Watch Dissection Of Tesla Model S Plaid Front Drive Unit) (Watch Dissection Of Tesla Model S Plaid Front Drive Unit) – testament to both materials and clever integration.

Durability Enhancements: The choice of materials directly ties into durability. The use of carbon fiber not only allows high speed but also means the rotor can endure repeated acceleration cycles without fatigue cracking (metals alone might eventually fatigue from the hoop stress). The copper rotor in induction motors was an earlier Tesla innovation – copper has better conductivity (and thus lower resistive heating) than the aluminum used in most induction rotors, but casting pure copper is difficult due to its high melting point. Tesla mastered this for the original Model S, which speaks to their manufacturing prowess (Tesla Model 3 Motor — Everything I’ve Been Able To Learn About It (Welcome To The Machine) – CleanTechnica). In the new PM motors, they avoid rotor currents altogether, which improves durability (no rotor I²R losses to heat up the core). The magnets are likely retained with high-temperature adhesives and possibly mechanical features (the patent shows fixturing slots and dowels for holding parts during assembly (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents) (WO2021225902A1 – Permanent magnet motor with wrapping – Google Patents)). The entire motor is also sealed and liquid-cooled, which helps maintain moderate temperatures of the materials, thereby extending life. Taken together, Tesla’s material and manufacturing choices enable a lightweight yet robust motor that can output high power repeatedly – indeed, the Plaid’s powertrain is advertised to sustain back-to-back quarter-mile runs with far less performance degradation than previous Model S versions (This Is Tesla Model S Plaid’s Drive Unit) (in fact, the new design allows five times more high-speed runs before thermal limiting compared to the prior generation (This Is Tesla Model S Plaid’s Drive Unit)).

4. Thermal Management and Cooling Systems

High-performance EV motors generate a tremendous amount of heat under load – from copper losses in windings, iron losses in laminations, and inverter switching losses. Managing this heat is crucial to maintain performance and prevent damage. Tesla has progressively improved its motor cooling systems from the early Model S to the latest Plaid.

Early vs. New Cooling Approaches: The first-generation Model S motors used a water-glycol cooling jacket around the motor casing. Coolant would flow around the outside of the stator housing to take away heat. While this helps, it primarily cools the exterior and relies on conduction from the stator core outwards. The windings themselves (especially their inner portions) and the rotor could still get quite hot because there was no direct fluid contact. By the time of the Model 3, Tesla switched to a far more effective direct oil cooling system (Two Types of Tesla Model 3 Motors: Everything You Need to Know) (Two Types of Tesla Model 3 Motors: Everything You Need to Know). In the Model 3’s drive unit, Tesla uses the gearbox oil (or a dedicated cooling oil) to directly cool both stator and rotor. Specifically, the stator has 168 small cooling channels drilled through the lamination stack (in the yoke region of the stator) (Two Types of Tesla Model 3 Motors: Everything You Need to Know). Coolant is pumped through these axial holes, carrying heat away from inside the stator. At the ends, Tesla uses plastic distributor rings with spray jets that squirt cooling oil directly onto the end windings of the stator (Two Types of Tesla Model 3 Motors: Everything You Need to Know). By impinging oil on the hottest part of the windings (the end turns, which are not in contact with the laminated core), Tesla dramatically increases cooling of the copper. Meanwhile, the rotor is cooled via the hollow shaft: the rotor shaft has internal passages and holes that sling oil into the rotor cavity (Two Types of Tesla Model 3 Motors: Everything You Need to Know). As the rotor spins, oil is centrifugally flung through these holes, creating an oil mist or spray that directly contacts the rotor interior and magnets. This “inside-out” cooling removes heat from the rotor and also cools the inner surface of the stator from within (Two Types of Tesla Model 3 Motors: Everything You Need to Know). Together, this composite stator+rotor oil cooling design yields a huge boost in continuous power capability – Tesla’s engineers noted up to a 40–50% increase in continuous torque output compared to a water-jacket cooled motor of similar size (Two Types of Tesla Model 3 Motors: Everything You Need to Know).

Cooling in Model S Plaid Motors: The Plaid tri-motor likely employs a similar oil-based cooling strategy, possibly with further refinements. One challenge with the carbon-sleeved rotor is that carbon fiber is a thermal insulator, so getting heat out of the rotor is harder. Tesla likely relies on the rotor’s internal cooling via the hollow shaft and oil spray to pull heat from the rotor core and magnets, since the carbon sleeve prevents radial heat escape. The oil that cools the rotor then exits and carries heat into the oil circuit. That oil, as well as the stator oil, then flows through a heat exchanger (which is connected to the car’s coolant loop). Tesla upgraded the heat exchangers and pump in the Plaid – it features a new “heat pump” thermal system for the HVAC and powertrain with a radiator twice the size of before (This Is Tesla Model S Plaid’s Drive Unit). This helps quickly reject heat from the coolant/oil into the ambient air. In effect, the Plaid can cool its motors much faster than earlier models, which is why it can sustain more launches before needing to reduce power (This Is Tesla Model S Plaid’s Drive Unit).

Direct vs. Indirect Cooling – Advantages: Tesla’s approach of directly cooling the motor’s internals with oil is now considered state-of-the-art for performance EVs. It brings the cooling medium right to the heat sources (copper windings and rotor). Oil (or automatic transmission fluid) is often used because it is an electrical insulator – it won’t short out the motor – and it can reach hot spots that water/glycol could not. The oil is then usually cooled via a water-cooled heat exchanger, tying into the car’s primary cooling loop. This is how Tesla can advertise consistent performance: the continuous power rating of the Model 3’s motor is far higher than if it were only water-jacket cooled. By contrast, a purely water-cooled casing might be simpler but would lead to heat saturating the motor core on long high-power runs. We can see parallels in other EVs like the Nissan Leaf (which in early versions had no active cooling and suffered power loss) versus Tesla’s aggressive cooling that keeps temperatures in check.

Fluid Dynamics Considerations: Within Tesla’s motor, the oil flow is carefully engineered. The stator cooling channels must distribute oil evenly and avoid any areas of stagnant flow. The spray bars on the ends ensure each section of end windings gets sprayed, and the flow rate is tuned so that the oil carries away maximum heat but doesn’t churn excessively (to avoid foaming or windage losses). The rotor spray through the shaft must also be metered – too much oil and you waste energy pumping and churning it; too little and cooling suffers. Tesla likely uses computational fluid dynamics (CFD) simulations to design these cooling pathways for optimal heat transfer. The gearbox and inverter are also tied into the cooling loop. The same oil lubricates the reduction gears and then likely goes through an oil-to-coolant cooler. The inverter’s power electronics typically have their own coolant channels (water/glycol) in the aluminum heat sink mounting the MOSFETs, which then connect to the radiator. In the Plaid’s front unit, the combined motor+inverter+gearbox operates as one module with shared cooling so that waste heat from the motor and inverter both get handled by the car’s central cooling system. Tesla increased coolant flow and radiator capacity for Plaid, indicating that sustaining ~1000 hp requires rejecting hundreds of kW of heat under peak loads.

In summary, Tesla moved from a modest water-cooled housing in early models to an integrated oil cooling solution that directly bathes the motor internals. This was a key enabler for the high continuous power of the Model 3’s motor and even more so for the Plaid’s motors. It’s a competitive advantage in Tesla’s design – for instance, one reason the Porsche Taycan can do repeat launches is its excellent cooling (it also uses advanced cooling channels and even a refrigerant-based cooling for its battery), and Tesla reached similar or better sustained performance by ensuring their motors stay within optimal temperature even when pushed hard.

(Two Types of Tesla Model 3 Motors: Everything You Need to Know) Figure 2: A Tesla stator assembly (Model 3/Y) showing oil cooling channels in the steel laminations (small holes around the stator circumference) and the insulated copper windings. Tesla’s “spray cooling” sends oil through these channels and onto the end windings for direct heat removal (Two Types of Tesla Model 3 Motors: Everything You Need to Know) (Two Types of Tesla Model 3 Motors: Everything You Need to Know). This advanced cooling design improves continuous torque by ~50% over older water-jacket cooling (Two Types of Tesla Model 3 Motors: Everything You Need to Know).

5. Power Electronics and Control (Inverters & Software Integration)

No electric motor can perform without a sophisticated control system – in EVs, this is the job of the inverter and the software that drives it. Tesla designs its own motor control electronics (inverters) in-house, packaging them with the motor in the drive unit. The inverter converts the DC battery power to multi-phase AC with precise frequency and amplitude to control torque and speed. Several key aspects define Tesla’s approach: the use of silicon carbide (SiC) transistors for fast and efficient switching, high integration between inverter and motor, and intelligent software control algorithms.

Inverter Architecture (SiC MOSFETs): Starting with the Model 3, Tesla made a significant leap by adopting SiC MOSFET power transistors in the main inverter, instead of traditional silicon IGBTs. SiC MOSFETs can switch faster and have lower losses at high voltages. This yields higher efficiency, especially at part load. For example, the Model 3’s inverter (supplied by STMicroelectronics) uses integrated SiC modules – each module containing multiple MOSFET dies, copper clips, and direct cooling for the transistors ([PDF] STMicroelectronics SiC Module – Tesla Model 3 Inverter – Yole Group). The result is an inverter that can handle hundreds of amps with minimal switching loss. With SiC, Tesla can raise the PWM switching frequency (reducing harmonic currents in the motor for smoother operation) without undue heat in the transistors. Higher switching frequency also helps with fine-tuned torque control and reduces the size of filter components. Tesla’s inverter is a three-phase, two-level design (one half-bridge per phase leg), with likely 24 MOSFET packages or more arranged to achieve the necessary current rating (some reports indicate Tesla was able to reduce the count of SiC devices by using newer generation parts) (Examining Tesla’s 75% SiC Reduction – PGC Consultancy) (STPOWER SiC MOSFETs – STMicroelectronics). The use of a 400 V battery system means the devices see up to ~400 V DC, which is well within the range of 650 V–900 V rated SiC MOSFETs. The Plaid presumably also uses SiC transistors (it was introduced after the Model 3), and with its ~450 V pack, SiC is almost mandatory for efficient high-current switching. The inverter and the motor are tightly integrated physically – in the Plaid drive unit photo (Figure 1), the inverter is the small box on top of the motor. Short connections mean lower inductance and less energy loss during high-frequency switching. Each inverter is controlled by a high-performance microcontroller or FPGA, running Tesla’s control software.

Motor Control Software: Tesla’s motor control algorithms are a critical (though less visible) component of performance. The controller performs field-oriented control (FOC), meaning it regulates the AC phase currents in a rotating reference frame (d,q axis) to independently manage torque-producing current vs. magnetization current. By commanding currents in real-time, Tesla’s software can produce a precise torque request in milliseconds. One impressive outcome is traction control and stability control directly via motor torque – the Tesla can modulate torque at each wheel far faster than traditional traction control (which uses brakes). With the two rear motors in Plaid, the car can do torque vectoring, adjusting left vs. right wheel torque to stabilize the car or enhance cornering. All of this is purely software-driven on top of the hardware capabilities.

Tesla also uses software to manage torque ripple and NVH (noise, vibration, harshness). If any torque pulsations are detected, the controller can inject counteracting harmonics. As noted in a discussion by Tesla’s motor engineers, even if reluctance motors tend to have ripple, “clever inverter waveforms” can address much of it (The new Model 3 motor. Its history and what it is likely to be … – Reddit). The software also protects the motor – monitoring temperatures (in winding, inverter, etc.) and reducing power before anything overheats. In the Plaid, the car will intelligently distribute load among the three motors and can even decide to deactivate one if not needed for efficiency. For instance, at steady cruise, the car might primarily use one axle (like front motor only in some scenarios) to minimize losses, similar to how Model 3 uses mostly the rear PM motor in normal driving. This torque blending is optimized in real-time: Tesla’s Vehicle Control Unit will shift torque between front/rear (or left/right in Plaid) to maximize overall efficiency, based on motor efficiency maps. Such integration between motor control and vehicle control is a Tesla specialty.

Integration with Vehicle Systems: The inverters communicate with the central car computer for coordination. For example, in Launch Mode, the Plaid’s software might pre-heat the motors to an optimal temperature (for better electrical resistance or magnet performance) and pre-cool the battery, and then manage all three inverters to launch the car with minimal wheelspin, even learning surface grip. The tight integration of motor, inverter, gearbox, and control in Tesla’s drive units is akin to a digital DDS (Drive Delivery System) that can be updated over-the-air. Notably, Tesla has increased power in some models via software updates alone, indicating there were margins in the inverter/motor that they could exploit with more aggressive tuning.

On the hardware side, Tesla’s inverter PCB and gate driver design emphasize reliability and fast response. The gate drivers (which control the MOSFETs) likely ensure simultaneous and even switching of parallel transistors. They also incorporate desaturation detection and other protection circuits to shut down the inverter in case of overcurrent. The DC link capacitor (which smooths the DC supply) is integrated right at the inverter input and uses high-quality film capacitors to handle the ripple current. All of this is packaged in a compact module sitting atop the motor for short interconnects.

Finally, Tesla’s use of SiC and advanced control yields high efficiency for the whole drive. The inverter can reach >98% efficiency at peak, and the motor often exceeds 95% in its mid-load sweet spot. This means less waste heat to remove and more of the battery energy translating to wheel power or range. By designing everything in-house – from the motor to the inverter hardware to the control firmware – Tesla can optimize the entire system holistically. This vertical integration is a big reason why Tesla has achieved industry-leading EV performance.

6. Comparative Analysis with Other Performance EV Motors

Tesla’s motor technology in the Model 3 and Model S Plaid stands out, but how does it compare to other state-of-the-art performance EVs? We look at a few notable examples – Porsche’s Taycan, Lucid’s Air, and Rimac’s Nevera – to highlight similarities, differences, and the trade-offs in design philosophies.

Porsche Taycan (Turbo S) – High Performance Dual Motor with 2-Speed Gearbox

Porsche took a different approach in the Taycan, its high-end sports sedan. The Taycan uses dual permanent magnet synchronous motors (PMSM) – one on each axle (so two motors total) – that are also designed in-house (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS). Porsche’s motors are notable for using hairpin winding technology from the start, achieving about a 70% slot fill (versus ~45% in conventional windings) (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS). This is very much aligned with what Tesla is now doing with flat wire – higher copper fill and easier cooling. In fact, Porsche cools its motors with a water glycol jacket plus oil spray on the windings. There’s mention of oil cooling implementation in research for hairpin EV motors (Animation of the cooling circuit of the PORSCHE Taycan (courtesy), and Porsche in practice is known for robust thermal management to enable repeatable performance (the Taycan can do multiple launch control starts without significant power fade).

One signature difference is Porsche’s use of a 2-speed transmission on the rear motor. The rear motor of the Taycan has a two-speed gearbox (one gear for acceleration, second gear for top speed/efficiency) (Technical Feature: The Porsche Taycan). This allowed Porsche to use a slightly smaller motor and still achieve both excellent low-end torque and >250 km/h top speed. In contrast, Tesla chose a single-speed gearbox and instead pushed the motor’s RPM capability (with the carbon sleeve rotor in Plaid) to achieve the top speed. The Taycan’s rear motor maxes out around 16,000 rpm (Technical Feature: The Porsche Taycan) (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS), whereas the Plaid’s motors go to ~20,000 rpm. The 2-speed adds mechanical complexity and about gearbox weight, but it means the motor can stay in a more efficient RPM range at high speeds. Tesla avoids that complexity by relying on the motor’s brute-force RPM and the battery’s power.

In terms of power and power density: The Taycan Turbo S’s combined output is up to 560 kW (750 hp) in overboost, similar to Plaid’s 760 kW but with one less motor. The rear motor is quite large – the Porsche spec sheet notes the rear motor weighs ~170 kg (likely including its gearbox) (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS). That is heavier than a Plaid rear drive unit (~95 kg including everything) per motor. So Tesla’s power density appears higher. Indeed, Lucid (see next) claims Tesla’s gravimetric power density for Model S/3 motors is around 3 kW/kg (Behind the Wheel, Under the Hood of World’s First 500-Mile EV – IEEE Spectrum). Porsche’s motors, while very efficient and well-made, didn’t push for minimal weight as much – Porsche likely optimized for durability and repeatability (the motors have substantial thermal mass). Porsche also uses an 800 V architecture, which means lower current for the same power and thus potentially smaller cables and less heating. They employ customized SiC inverters as well (600 A, 800 V modules) (Technical Feature: The Porsche Taycan – Porsche Newsroom AUS). In summary, Porsche’s motor tech is on par with Tesla’s in using PMSM with hairpins and advanced cooling, but Tesla’s Plaid motor achieves similar or better performance with lighter units (owing to things like the carbon rotor and perhaps more aggressive design limits), whereas Porsche uses a multi-gear approach and slightly more conservative motor RPM.

Lucid Air – Miniaturized High-Efficiency Motor with Unmatched Power Density

Lucid Motors, led by ex-Tesla engineer Peter Rawlinson, developed a ground-breaking drive unit for the Lucid Air luxury sedan. The Lucid Air’s rear drive unit (one per axle, in the AWD version) is astonishingly compact and light. The entire drive unit (motor + inverter + reduction gear + differential) weighs only 74 kg, yet it can output 500 kW (670 hp) (How Lucid leaps past Tesla with smaller motors – Green Car Reports) (LucidMotors | Lucid’s Electric Drive Unit. The stats speak … – Facebook). This translates to a gravimetric power density of ~6.5 kW/kg, which an analysis noted is more than double that of Tesla’s Model 3/Y drive units (which are ~3 kW/kg) (Behind the Wheel, Under the Hood of World’s First 500-Mile EV – IEEE Spectrum). Lucid achieved this by focusing on every aspect: a high-speed, high-voltage motor, innovative cooling, and extreme integration. The Lucid motor is a permanent magnet AC motor like Tesla’s, reportedly capable of 20,000 rpm as well (Behind the Wheel, Under the Hood of World’s First 500-Mile EV – IEEE Spectrum). They use a higher nominal voltage (~900 V), allowing the same power with lower current – this reduces resistive losses and enables smaller wires and inverter components. The inverter in the Lucid is also SiC-based and extremely compact, fitting in the motor housing.

One highlight is Lucid’s approach to cooling and winding. Lucid uses proprietary microjet cooling in its motors – they have spoken about a cooling system that uses a high surface area to remove heat (possibly a network of cooling channels or jets that target hot spots). Their motor is also likely hairpin wound or similarly high fill. The Lucid motor’s form factor is different: it’s axially shorter and may use an axial flux-like architecture for some elements (though it’s likely still radial flux, as axial flux motors usually look different). From images, the Lucid drive unit can literally fit in a carry-on suitcase, highlighting how tightly packaged it is (Behind the Wheel, Under the Hood of World’s First 500-Mile EV – IEEE Spectrum). Lucid claims their motor is “two and a half times more power dense” than the closest competitor and uses exotic materials like a custom continuous carbon fiber winding for certain components and perhaps advanced magnet arrangements (Lucid Motors releases details about its electric drivetrain technology). They also integrate the inverter and reduction gear seamlessly. Tesla’s motors are already good on power density, but Lucid pushed the envelope further, possibly by using a higher stress on materials (taking advantage of the lower current due to high voltage).

In terms of performance, the Lucid Air Dream Edition has up to 828 kW (1111 hp) with its dual motors – beating the Model S Plaid slightly in total output. It also has an exceptional range (long efficiency optimization). However, the trade-offs might be cost and manufacturing complexity. Lucid’s motor likely uses even more expensive materials or harder-to-manufacture parts (they emphasized their hands-on vertical integration like Tesla). For example, achieving 900 V means needing components that can handle that, and ensuring insulation integrity at those voltages in a small motor is non-trivial. The Lucid inverter uses a custom MOSFET package, possibly single-piece versus Tesla’s multiple devices approach.

Overall, Lucid’s motors exemplify what happens if you extremely optimize for power density: you get a super-compact powerhouse, at higher cost. Tesla’s Plaid motors are slightly larger/heavier per kW, but still within practical differences, and Tesla benefits from economies of scale and cost optimizations that a boutique maker like Lucid might not have initially. Lucid’s achievements, such as ~9 hp per pound motor output and integrated differential (How Lucid leaps past Tesla with smaller motors – Green Car Reports) (LucidMotors | Lucid’s Electric Drive Unit. The stats speak … – Facebook), set a benchmark that even Tesla will aim to meet or exceed in future designs.

Rimac Nevera – Quad Motor Torque-Vectoring Hypercar

The Rimac Nevera (formerly C_Two) is a 1914-horsepower all-electric hypercar from Croatia’s Rimac Automobili. It uses four independent motors, one driving each wheel, for a truly AWD torque-vectoring system. Each motor is a PMSM delivering on the order of 350 kW (470 hp) and a prodigious amount of torque with dedicated reduction gearboxes. The Nevera’s total output of ~1.4 MW exceeds the Plaid’s 0.76 MW by a wide margin, but it achieves this by simply using more motors and a much larger battery (120 kWh pack capable of enormous discharge).

In terms of motor tech, Rimac’s are also permanent magnet AC motors with likely SiC inverters (Rimac specializes in high-performance EV components, and they supply others as well). Each motor may not spin as high as Tesla’s or Lucid’s since the car might not need 20k rpm given the gearing choices; however, the Nevera is capable of ~350 km/h (217 mph), so the motors do need to spin fast or use multi-speed. Rimac hasn’t publicized a multi-gear system, so it’s presumed they use single-speed reductions (possibly around 8:1 or 10:1 ratios) with high motor RPM. The advantage Rimac has is each motor is smaller in load (one per wheel), so they can optimize each for its corner of the car, and there is built-in redundancy (if one motor gets hot, the others can compensate to a degree). They can also do extreme torque vectoring – for example, applying negative torque (regenerative braking) on inner wheels while positive on outer wheels in a turn, to aid rotation.

Comparatively, Tesla’s approach is more focused on efficiency and cost-effectiveness for a sedan. Rimac’s motors might use even more exotic cooling (perhaps oil cooling like Tesla, since for that level of power they must). The power density might not need to be as high as Lucid’s because they have space to distribute four motors. But Rimac has likely innovated on the inverter front – maybe using extremely high phase currents and custom power electronics to manage nearly 2000 A combined or more.

One can see Tesla’s Plaid as a more mass-market oriented approach to insane performance: it uses only three motors and an ~100 kWh pack to get supercar results repeatedly, in a full-size sedan that can be produced in volume. Rimac’s Nevera is a no-compromise halo car, leveraging quadruple motors and a massive battery; it outguns the Plaid in raw numbers (0–60 in ~1.85s, etc.), but it’s also a $2M limited-production vehicle. It validates that Tesla’s motor tech is not far off the most elite: in fact, aside from the Nevera, the Plaid is equal or superior in powertrain to almost any production EV up to 2025.

Summary of Innovations and Trade-offs: Tesla’s motors (Plaid/Model 3) and these competitors all use permanent magnet AC technology – highlighting that PMSMs are the preferred solution for high-performance EVs today, due to their efficiency and power density. All employ some form of advanced cooling (oil or refrigerant spray), and high-speed operation with careful rotor engineering. Tesla’s unique edge with the Plaid is the carbon-sleeved rotor – none of the others in production have that (as of yet). Porsche chose a 2-speed gearbox instead; Lucid chose ultra-high voltage and super density; Rimac chose multiple motors. Each choice comes with trade-offs: Carbon sleeve = manufacturing complexity but simpler drivetrain (Tesla); 2-speed = added weight/complexity but lower motor stress (Porsche); High voltage & tiny motor = need top-grade insulation and electronics (Lucid); Quad motors = weight and cost multiplied (Rimac). Tesla’s balance of innovations gives them an advantage in a practical sense: the Plaid powertrain is relatively simple (no shifting, only three moving parts in motors, etc.) yet delivers world-class performance. It’s telling that an independent teardown of the Plaid’s front motor remarked it’s basically the same as Model 3’s motor but “upgraded for higher speed operation by incorporating a carbon-fiber overwrap to keep the rotor from coming apart at 200 MPH” (Watch Dissection Of Tesla Model S Plaid Front Drive Unit). This single change allowed Tesla to double the motor’s peak RPM and significantly boost power. Other EV makers will likely explore similar rotor reinforcement to push motor speeds higher instead of adding gears or more motors – because higher RPM is a very attractive way to get more power from a given motor size (power is torque × speed).

7. Conclusion and Future Outlook

Tesla’s in-house motor development has been a key enabler of its EV dominance. The Model 3’s permanent magnet motor introduced in 2017 brought a step-change in efficiency and compactness, while the Model S Plaid’s tri-motor system in 2021 showed how far the limits could be pushed by inventive engineering (carbon-sleeved rotors, high-RPM design, and superb integration). These motors exhibit a careful balance of high torque (thanks to advanced electromagnetic design and use of reluctance torque), high speed (thanks to strong materials and rotor containment), and high efficiency (thanks to permanent magnets, SiC electronics, and smart control). Tesla’s use of innovative cooling and power electronics allows these motors to sustain performance that was previously unheard of in an electric sedan.

When compared with other leading EV makers, Tesla stands competitive or ahead: Porsche’s motors are excellent but use a different strategy; Lucid’s motors achieve even higher density, which Tesla may answer in future iterations; Rimac’s approach shows what ultimate performance can do with more motors. It’s a fascinating convergence where most players have gravitated to similar fundamental solutions (PMSM motors with hairpin windings and oil cooling), with each adding their own twist. Tesla’s willingness to develop new manufacturing techniques (like the carbon wrapping machine) and vertical integration of motor + inverter + software is a distinguishing factor that gives them an engineering edge.

Looking forward, Tesla has hinted at even further innovations – at the 2023 Investor Day, Tesla revealed plans for a next-generation motor that uses no rare earth magnets (Mystery of the Tesla’s Next-Gen Zero-Rare-Earth Electric Motor), which suggests either a shift to an induction or switched reluctance type or new magnet materials (perhaps ferrite magnets with clever design). They have claimed this next-gen drive unit will be cheaper and scalable for high-volume production (likely for future models like the Cybertruck or a smaller car). It will be interesting to see if they can maintain the performance levels without rare earths; it may involve revisiting some concepts (e.g. a refined induction motor or a hybrid excitation design).

In any case, Tesla’s current Model 3 and Model S Plaid motors represent a pinnacle of EV motor design as of 2025 – blending high-tech materials, thoughtful electromagnetic design, and cutting-edge power electronics. They are a testament to how far electric motor technology has advanced from the simple AC induction motors in the original Roadster. With over a decade of R&D, Tesla has achieved motors that are compact enough to hold in your hands yet capable of propelling a two-ton family sedan faster than almost any supercar (Tesla Publishes Patent for Permanent Magnet Motor with Carbon Wrapping). The combination of patent-backed innovations and real-world engineering choices makes Tesla’s motors a benchmark in the industry. As EV competition heats up, we can expect even more exciting developments in motor technology – but for now, the Model 3 and Plaid motors are truly state-of-the-art.