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Electric vehicles are more than battery packs and sleek user interfaces — their powertrains are evolving fast, and Tesla remains at the forefront. In a recent teardown walkthrough, Munro & Associates examined the electric motors from the Tesla Model Y and Model 3, comparing them not just to each other, but to motors from leading competitors like Audi, Nissan, Chevy, BMW, Jaguar, and Toyota.
For EV engineers, investors, and enthusiasts, the insights uncovered offer a rare behind-the-scenes look at how Tesla designs its motors for performance, efficiency, and cost-effectiveness.
Induction vs. Permanent Magnet: Tesla’s Dual Strategy
Tesla’s Model Y front motor is an induction motor, bearing a striking resemblance to the Model 3’s. Induction motors rely on alternating current to create a rotating magnetic field. Notably, the Model Y’s induction motor features an offset transfer case — different from the in-line setup seen in some rivals like Jaguar.
The rear motor, by contrast, is a permanent magnet (PM) type — more energy-efficient under typical driving loads. While the industry has speculated Tesla might be using a switched reluctance design or hybrid strategy, teardown evidence points clearly to a PM configuration, albeit with exotic materials in the aluminum casing that have yet to be fully explained.
Each motor includes a small oil filter system — essential for keeping the oil (used in gearboxes, not transmission fluid) clean and flowing smoothly through critical components.
Cooling Matters: Tesla’s Unique Approach
Effective thermal management is vital in electric powertrains. Tesla deploys intricate oil squirters to cool its motors from the inside out. Seals, tiny holes, and case designs work in concert to direct oil flow precisely where it’s needed.
This isn’t unique to the Model Y — similar cooling techniques appear in earlier Model 3s as well. But it’s a system that separates Tesla from manufacturers that rely on more traditional or passive cooling mechanisms.
Comparing Industry Designs: What Tesla Does Differently
Munro’s walkthrough goes beyond Tesla, showcasing how different OEMs tackle motor design. Here’s what stood out:
Audi E-Tron
Uses an induction motor with laminated cores welded together and aluminum poured between plates — a heavy but robust design.
Jaguar I-Pace
Employs a unique magnet layout in triplet configurations — another example of proprietary “secret sauce” in EV motor design.
Chevy Bolt
Older models feature oversized hairpin windings; newer versions use more refined hairpin architecture. Hairpins improve manufacturability and automation — a cost-saving advantage.
Nissan Leaf
Surprised teardown engineers with an unconventional flux pattern when examined under cloth — a unique configuration not previously encountered.
Toyota Prius & BMW i3
These legacy systems use varied magnet placements, including multiple small magnets per laminate. The design reflects generational transitions in hybrid motor tech.
Tesla’s Stator and Rotor Architecture: Machine Precision
Tesla’s rotors differ sharply from Audi’s cast-aluminum approach. Instead of pouring metal into molds, Tesla machines copper components and vacuum brazes them. The level of precision in this method is expensive — but delivers better control over tolerances and performance.
Each copper segment fits tightly with adjacent steel elements, making the overall construction denser and thermally efficient.
The stator — the stationary part of the motor — uses densely packed thin copper windings. Tesla opts for smaller wires over bulkier hairpins, enabling tighter packing and greater heat dissipation. This maximizes magnetic flux and minimizes resistance — translating into better power-to-weight ratios and superior efficiency.
Inside the PM Motor: Tesla’s Magnetic Secrets
A close-up view of the PM motor reveals magnets that aren’t a single block, but rather a set of four bonded magnetic strips. These are not true Halbach arrays, but they behave similarly — focusing magnetic flux where it’s needed most while canceling stray fields.
While some expected more exotic materials or rare-earth innovation, Tesla’s design shows that smart orientation and adhesive strategy can enhance performance without adding exotic cost.
Material Cost, Circuit Boards, and BMS Insights
Munro’s teardown isn’t just physical — it’s financial. The teardown team maps out bill-of-material costs, cooling diagrams, and even HVAC gas flow for the Model 3. Circuit boards are scrutinized down to the integrated circuits, revealing design efficiencies and material sourcing strategies.
They’ve also benchmarked Tesla’s Battery Management System (BMS) against BMW and GM. At the time, Tesla’s BMS architecture was a breakthrough, earning praise for its modular design and scalability.
Engineering Takeaways: Why Tesla Stands Out
From machining to magnet layout, Tesla’s motor development reflects its broader strategy: own the entire drivetrain experience, optimize for manufacturability, and design for energy density.
Three key differentiators:
- Manufacturing Control – Tesla avoids casting rotors, opting for machine-tooled copper and steel with vacuum brazing for durability.
- Cooling Precision – Integrated oil cooling features show forethought in thermal management and efficiency.
- Custom Magnet Configurations – Tesla fine-tunes magnet orientation and size for power density and cost balance.
Final Thoughts: The Motor War is Just Starting
What does the future hold for EV motors? With everyone pursuing different routes — hairpin vs winding, cast vs machined, PM vs induction — it’s clear the race is still on. Tesla continues to refine its designs while competitors bring new twists to rotor-stator configurations.
As we look ahead, expect innovation not just in battery tech, but in the heart of the EV drivetrain — the motor.
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Dive deeper into teardown insights, side-by-side EV comparisons, and lean engineering analysis by visiting Munro & Associates.