If you care about the Chevrolet Equinox EV and it’s motor efficiency, Munro’s latest deep dive with GM powertrain leaders is essential reading. The front drive unit powering GM’s Ultium crossovers helps the Equinox EV achieve 319 miles from an 85 kWh pack — impressive range for its size and aerodynamics — showing how tightly optimized the entire system is, not just the motor itself.
A Common Motor, Tuned by the System
GM’s 180 kW, ~350 N·m interior permanent-magnet (IPM) machine is the “middle” member of a three-motor family; the base motor stays common while the gearbox can vary to suit vehicle targets. Two gear ratios — 11.59 and 9.87 — let calibration teams balance launch feel, cruising efficiency, and NVH across platforms. In practice, that system view matters more than any single peak-efficiency number.
Consequently, this unit now appears in a broad slate of vehicles: Chevrolet Equinox EV, Blazer EV (front unit), Honda Prologue, Acura ZDX, Cadillac Lyriq/Optiq, plus additional Buick and Cadillac applications globally. Scale lowers cost; commonization accelerates launch.
Why It’s Efficient: Hairpins, Oil, and Packaging
Start with copper.
GM’s bar-wound hairpin stator (now at its ninth iteration) improves slot fill and heat rejection. Unlike older round-wire designs that trapped heat, the hairpin layout lets oil move through the windings, pulling heat out where it’s generated. Meanwhile, oil also flows through the rotor to hold continuous performance, not just peaks.
Then, consider the cooling strategy. Rather than high-pressure, through-lamination oil galleries, GM uses a gravity-fed “rain” approach: oil gathers at the top of the casting (in installed orientation) and drains across the windings. It’s simpler, robust to temperature-dependent viscosity changes, and easier to validate for real-world grades and attitudes; manufacturing stays calmer, too.
Packaging completes the picture. Perched atop the drive unit is a tightly integrated five-in-one power electronics module: onboard charger, DC-DC converter, vehicle control computer, power distribution, and inverters (single for FWD; dual variant to support AWD). Short DC links cut copper, reduce losses, and shrink volume by roughly half versus prior, more distributed footprints. The upshot: drop the front DU in place and you’ve solved ~80% of the vehicle’s high-voltage integration.
Slot Count, Scaling, and Manufacturability
GM leans on a 96-slot stator and scales the family radially: more hairpin connectors per slot as power rises. This approach keeps wire size and forming tooling common while extending stack length and adding rows where needed. In other words, engineering gets the electromagnetic headroom it wants; manufacturing keeps the flexible line it needs. The result is power density you can pick up — literally — with a sub-220 hp package you can lift, yet still deliver muscular crossover performance.
Magnets, Supply, and Loss Reduction
Because light- and medium-load operation dominate real cycles, rotor loss matters. GM moved from single sintered magnet blocks to segmented assemblies glued into the IPM rotor. Segmentation reduces eddy current paths; operating temperature drops; efficiency rises. Yes, rotor cost nudges up — but if the trade saves battery, system cost falls overall. To bolster supply assurance, GM is working with U.S. magnet partners (e.g., MP Materials and VAC) to localize production.
Two Ratios, Many Roles
With 11.59 or 9.87:1, the same 180 kW unit can be the primary drive in Equinox EV or the secondary axle in performance and large-vehicle trims where a 250 kW rear machine leads. Calibration and micro-geometry refinement keep structure-borne gear noise in check — crucial when there’s no engine masking. Thus, GM spans base models to 600+ hp flagships with a coherent parts bin.
A Note on Park Systems and Cost
Legacy practice carries a traditional park pawl in the gearbox — familiar, proven, and inexpensive at scale. However, the vehicles also include electrically actuated parking brakes. As Munro notes, software-first parking strategies could retire the pawl and remove the back-roll “rock,” while saving hardware cost; redundancy can be handled with split circuits. GM says continuous benchmarking is underway; integrity comes first, but cost wins that preserve safety stay on the table.
What GM’s 180 kW Motor Design Means
- System over silo. Efficiency gains came from an integrated DU + power electronics package, not just a shiny motor map. Shorter DC links and fewer harnesses pay back immediately in loss, cost, mass, and packaging.
- Manufacturing-aware design. Hairpin stators and a scalable slot/connector pattern let GM run different motors on the same line; complexity lives in clever forming and assembly, not in bespoke part families.
- Thermal realism. Gravity-assisted oiling solves viscosity and attitude effects without exotic channels; it’s robust, cheap, and effective under real gradients.
- Strategic sourcing. Domestic magnet initiatives de-risk IPM dependence while enabling segmented-magnet loss cuts that shrink battery needs — the biggest lever in EV cost.
Looking ahead, GM even confirmed this 180 kW drive unit for the next Bolt (targeted as the 2027 Chevy Bolt), rounding out the portfolio with a high-efficiency compact that benefits directly from the same scalable hardware. That’s the very definition of platform leverage.
Equinox EV Motor Efficiency Takeaways
- Design to integrate, then optimize. Co-locate inverters, charger, DC-DC, and control with the DU to cut copper and simplify vehicle-level HV packaging; validate loss reductions with DC link modeling.
- Cool the copper you have. If you’re on hairpins, exploit oil access; model gravity-fed “rain” paths before pursuing high-pressure galleries that add complexity and viscosity sensitivity.
- Segment magnets where it pays. Run rotor eddy-loss sensitivity with segmented IPM layouts; if battery delta dominates cost, accept minor rotor cost increases.
- Simplify park strategy. Evaluate brake-based park with redundant circuits; verify customer feel (no roll-rock), and measure BOM savings for scale programs.
Keep Learning with Munro
Want deeper teardown analysis, cost models, and manufacturability reviews on the motor efficiency of drive units like the Equinox EV? Explore more engineering content and benchmarking insights with Munro & Associates. Or take a look at Munro Live — then apply the lessons to your next program.