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As Lexus enters the fully electric space with its first dedicated battery-electric vehicle (BEV) built on the e-TNGA platform, the team at Munro offers an in-depth teardown and engineering analysis of the 2023 Lexus RZ 450e. This comprehensive review highlights what sets the RZ apart from its platform siblings—the Toyota BZ4X and Subaru Solterra—and reveals Lexus’ strategy for cost, performance, and safety optimization in the premium EV segment.
Introducing the Lexus RZ 450e and e-TNGA Architecture
The RZ 450e is the first Lexus vehicle built on Toyota’s e-TNGA platform—a BEV-specific iteration of Toyota’s TNGA (Toyota New Global Architecture). Unlike converted internal combustion engine (ICE) vehicles, this platform supports BEV packaging from the ground up. However, the teardown reveals that the RZ shares many core components and strategies with other e-TNGA vehicles, such as the Toyota BZ4X.
While Lexus maintains its luxury branding through design and materials, many architectural choices remain consistent with Toyota’s broader cost-effective approach. The shared DNA is evident, but so are several enhancements in the Lexus version.
Material Choices and Crash Management
A key differentiator in the RZ 450e is the use of specific materials in the front-end crash structure. Unlike the Toyota BZ4X, which features a stamped beam for the lower impact zone, the Lexus uses an extruded member—suggesting an effort to improve energy absorption and reduce weight in a premium application. It’s unclear whether this is a rolling change or specific to Lexus, but the difference is notable.
Lexus uses a stamped steel cradle and crush can architecture to manage impact energy. This choice continues Toyota’s well-known defensive crash strategy. In addition, the RZ features large structural members that redirect crash loads away from the cabin. This approach aligns with Small Overlap Rigid Barrier (SORB) countermeasures and reinforces occupant protection.
Front-End Structure and Closed Architecture
One standout in the teardown is the RZ’s closed front-end architecture. In contrast, most modern unibody EVs—like the Tesla Model 3 and Y, Hyundai Ioniq 5, and Ford Mustang Mach-E—use open front-end designs. These allow for simpler, horizontal assembly of cooling modules. The RZ breaks from that trend. Instead, it uses a vertically integrated front cradle and cooling system, likely pre-assembled and installed as a single unit. This design shift hints at a different approach to manufacturing and packaging efficiency.
This design includes a bolt-in cross member that passes through e-coat and final paint stages—unusual in today’s modular assembly landscape. While this might increase manufacturing complexity, it could also aid in structural integrity and crash performance.
Aero and Styling Integration
To retain signature Lexus styling, the RZ incorporates an off-fascia active grille shutter (AGS) system. Unlike on-fascia AGS used in other EVs to maximize aerodynamic efficiency, the RZ’s system supports traditional Lexus front-end aesthetics. This compromise reflects the brand’s effort to retain recognizable identity without fully committing to ultra-smooth EV aero styling.
Electric Drivetrain and Motor Layout
The RZ 450e employs a dual-motor all-wheel-drive system with a front-biased power distribution. The front permanent magnet motor delivers roughly 200 hp and 196 lb-ft of torque, while the rear contributes approximately 106 hp and 124 lb-ft. These outputs align with expectations for a luxury crossover but fall short of leading EVs in the same class, particularly in range.
Packaging of the motor units remains conservative. The front cradle dips below to accommodate the drive module, with integrated steel plates and crush structures offering protection to high-voltage components. The design prioritizes crash resilience, a hallmark of Toyota engineering.
Battery Pack Design and Protection
The RZ uses a 71.4 kWh lithium-ion battery pack, similar to its Toyota and Subaru siblings. Real-world range is limited—approximately 220 miles under ideal conditions—lagging behind competitors like the Tesla Model Y and Hyundai Ioniq 5.
To protect this high-cost component, Lexus employs a multi-layered shield: a stamped aluminum outer panel, steel collars, and a corrugated steel internal support structure. The pack is integrated with the chassis using a cradle and double plates to manage crush energy in frontal impacts. These design choices reflect a clear intent to prioritize occupant safety and battery longevity.
Underbody and Rear Suspension
Underbody protection is enhanced by steel skid plates and localized noise-vibration-harshness (NVH) shielding. Foam and injection-molded components surround high-noise areas near the inverters. However, Lexus avoids full-vehicle NVH encapsulation, likely as a cost-saving measure.
At the rear, the vehicle employs a twist-beam suspension setup using stamped steel components. While not as performance-oriented as independent rear suspension systems, this layout provides cost and weight advantages. In fact, several components—including the upper control arms—are extremely simple weldments, favoring global manufacturability and low capital investment.
Steel vs. Aluminum Trade-offs
The teardown highlights a broader trend in EV design: many OEMs are reverting to steel components after initially experimenting with aluminum. Despite its lightweight benefits, aluminum’s cost and complexity often outweigh its advantages in mass production. Lexus, like others, finds stamped steel to be a practical compromise, offering strength, global scalability, and cost control.
This approach underscores Toyota’s conservative yet effective lean manufacturing strategy—one that can be replicated worldwide with minimal tooling changes.
Steering System and Global Packaging Challenges
The RZ 450e does not use a steer-by-wire system, instead relying on a conventional steering column. While steer-by-wire could simplify packaging and eliminate left-hand vs. right-hand drive design constraints, Lexus sticks with the traditional approach for now.
The steering motor is mounted to accommodate global variants, but the need to design for both driving orientations leads to compromises in packaging efficiency—especially in the cramped front-end of EVs.
Tesla, by contrast, has already moved away from supporting some right-hand-drive markets to streamline manufacturing. As more automakers face the same pressure, steer-by-wire could emerge as a key enabler for global architecture standardization.
Cost and Margin Considerations
Despite being a luxury vehicle, the Lexus RZ 450e reflects a tightrope walk between brand expectations and cost pressures. Battery packs remain the largest cost driver, and OEMs must balance weight, protection, and performance without breaking the bank.
The use of clamshell stampings, minimal bracketry, and simple weldments reflects a philosophy rooted in lean design. Lexus takes advantage of platform commonality and selective material upgrades to offer a premium product that’s financially viable in a tough EV market.
Final Thoughts and Takeaways
The Lexus RZ 450e offers a fascinating window into Toyota’s evolving EV strategy. While much of the architecture is shared with the BZ4X, Lexus adds subtle refinements in material choice, crash strategy, and styling to justify its premium positioning.
For automotive engineers and investors, the RZ shows how legacy OEMs are adapting existing manufacturing philosophies to meet the demands of electric mobility. It’s not the most radical design, nor the most efficient—but it’s grounded, safe, and built with a global strategy in mind.
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