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Tesla’s adoption of a 48V electrical architecture in the Cybertruck marks a pivotal shift in electric vehicle design—delivering significant weight savings, wiring reduction, and higher data throughput. For decades, the auto industry has clung to a 12V standard, despite its inefficiencies. But thanks to decisive leadership and sound engineering, Tesla has shattered that inertia—ushering in a new era of lean automotive electrical systems.
Why 48V Matters: The Case Against 12V
For over 60 years, 12V electrical systems have dominated vehicle architecture. But as Elon Musk points out, this legacy voltage is “absurdly low” for modern needs. In electrical terms, the power transmitted through a conductor equals voltage multiplied by current. But the heating of that conductor—an efficiency loss—is proportional to the square of the current (I²R). To reduce power loss and heat, one can either reduce the current or the resistance. Reducing current is only practical by raising voltage.
That’s exactly what Tesla has done with the Cybertruck. By quadrupling voltage from 12V to 48V, Tesla dramatically cuts down on the amount of current needed for the same power load. That, in turn, allows for much thinner wiring—resulting in a significantly lighter wire harness and reduced use of copper.
Weight is one of the fiercest enemies of EV efficiency. Less copper not only lowers material costs but enhances range and performance. Musk estimates that this change slashes low-voltage wiring weight substantially, with some citing up to a 70% reduction in communication wiring alone.
Multiplexing Reinvented: Ethernet Over CAN Bus
The shift to 48V wasn’t the only radical update. Tesla also abandoned the aging CAN bus protocol for Ethernet, a move that radically increases data transmission speed across the vehicle. Traditional CAN buses limit how much data can flow, often requiring dozens of point-to-point wires to meet system bandwidth needs. Ethernet, by contrast, supports far higher data rates, enabling many devices to share a single bus with minimal latency.
This move isn’t about new tech—it’s about applying proven, high-bandwidth infrastructure that has long been used in computing and networking to the automotive sector. With Ethernet, Tesla can eliminate redundant wires, further reducing complexity and cost. The Cybertruck’s electrical system, then, isn’t just more powerful—it’s smarter and leaner.
Multiplexing—a technique where signals are combined for transmission—was attempted decades ago by OEMs like Ford, but often failed due to technical limitations and bureaucratic resistance. Ethernet makes multiplexing viable at last, and Tesla’s success underscores the power of matching vision with execution.
Why It Hasn’t Been Done Before
So if the benefits of 48V and Ethernet are so clear, why hasn’t the auto industry made the switch sooner? Musk’s answer: inertia and bureaucracy. Automotive suppliers are deeply invested in 12V tooling, supply chains, and design protocols. Every seat motor, window switch, and airbag controller is built around 12V. A shift would require an overhaul of every peripheral system—and a leader bold enough to mandate it.
Traditional automakers often paralyze innovation through layers of MBAs, legal reviews, and risk aversion. In contrast, Tesla’s flat decision-making structure allows engineers to act on common-sense innovations without waiting for boardroom approval.
“It’s not a Eureka moment,” Musk explains. “It’s just obvious.” The problem wasn’t technology—it was leadership.
Leadership That Understands Engineering
Musk emphasizes that effective leadership in a tech-centric company requires real understanding of the technology. That might seem obvious, but as he points out, very few CEOs—even in tech—could explain something as fundamental as I²R heating. That depth of understanding empowers Tesla’s leadership to make fast, technically sound decisions.
Sandy Munro, a longtime automotive expert, praises this approach. He contrasts Tesla’s decisiveness with the inertia of legacy OEMs, where ideas are often killed not by feasibility, but by fear of failure or legal exposure. Without a leader to say, “Just do it,” engineering-led innovation often dies on the vine.
In Tesla’s case, leadership didn’t just allow the shift to 48V and Ethernet—it demanded it. The result: a vehicle architecture that is lighter, simpler, and more scalable.
Benefits Beyond Weight
Tesla’s new electrical backbone isn’t just about cutting weight. It enables smarter integration across every system in the vehicle. With higher voltage and bandwidth, power electronics can operate more efficiently, control loops can be faster, and over-the-air updates more robust. Diagnostic capabilities also improve as Ethernet’s structure enables cleaner signal protocols and standardized data transmission.
Moreover, the lean wire harness opens the door for more radical vehicle architectures. By reducing weight and part count, automakers gain freedom in layout, modularity, and packaging—paving the way for more customizable, efficient platforms.
Cybertruck as a Testbed
Tesla’s decision to introduce these changes in the Cybertruck makes strategic sense. As a clean-sheet design, the Cybertruck isn’t shackled by legacy wiring or component compatibility. It serves as an ideal testbed for system-level innovations—setting the stage for future Tesla vehicles to inherit the 48V/Ethernet combo.
This approach also aligns with Munro & Associates’ core philosophy: lean design through first principles. The Cybertruck exemplifies the benefits of a system-wide teardown and reimagining. It reduces cost, complexity, and failure points—all hallmarks of effective lean engineering.
Industry Implications
Tesla’s shift puts pressure on traditional automakers. Once 48V and Ethernet become proven at scale, OEMs will face tough questions: Why stick with heavier, slower systems? Can they afford not to follow Tesla’s lead? Suppliers will also be pushed to adapt, offering 48V-compatible components and higher-speed networking solutions or risk obsolescence.
Just as Tesla’s move to direct sales disrupted dealership models, its internal architectural choices may now ripple across the supply chain.
Learn from the Leaders
Tesla’s 48V architecture isn’t just an engineering upgrade—it’s a case study in visionary leadership, bold execution, and the refusal to accept outdated norms. At Munro & Associates, we celebrate and analyze these breakthroughs—not just to admire them, but to help others build better.
Explore more teardown insights, leadership-driven design strategies, and electric vehicle innovations by visiting Munro & Associates. Subscribe to Munro Live for expert analysis, in-depth reviews, and the latest in EV technology. Stay informed, stay lean, and stay ahead.