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When it comes to electric vehicle (EV) engineering, less is often more. Lean design, efficient packaging, and simple thermal routing can make or break performance, reliability, and cost. Munro & Associates’ recent teardown of the Ford Mach-E’s thermal system puts this principle to the test—and exposes a tangled web of complexity that engineers and EV enthusiasts will want to study closely.
A Frunk Full of Surprises
The teardown begins with the removal of the Mach-E’s frunk, revealing a chaotic nest of components and hoses. We were immediately struck by the number of discrete elements: an inverter, DC-DC converter, onboard charger, four pumps (two with heatsinks), a compressor, a four-way valve, and a staggering number of commercial off-the-shelf (COTS) connectors.
This is not just a lot of parts. It’s a minefield for potential leaks and assembly errors.
Where Tesla’s frunk is clean and minimal, the Mach-E’s looks like a parts catalog exploded. We noted the presence of 31 spring clamps and 14 separate COTS connectors—ranging from T-junctions and nipples to 90-degree elbows—all increasing the chances for failure during manufacturing or long-term operation.
Leak Paths and Cost Pitfalls
Back in his days on Ford’s sealing and fastening task force, Sandy’s team worked hard to eliminate just these kinds of connectors. Why? They leak. Not every time, but often enough to create real warranty headaches.
The proliferation of hoses and joints isn’t just a quality control risk—it’s also a cost driver. Each connector, hose, and clamp adds material, labor, and inspection time. And when fluid runs through all of them, even the weight of the coolant becomes a factor. In lean manufacturing, every gram matters.
Ford’s box-on-box design further compounds the issue. Stacked modules, fastened with screws and brackets, complicate serviceability and drive up part count. This type of architecture flies in the face of Munro’s signature principle: if a part doesn’t need to move or be made from a different material, it should be eliminated or combined.
Lessons from the Past—and from Tesla
One bright spot? Ford has embraced some lean design principles over time. Case in point: a plastic battery tray the company adopted after retiring a steel-and-plastic hybrid version. That move alone saved Ford $2.5 million in just six months. It’s a reminder that Ford can make cost-effective engineering changes when the will is there.
Unfortunately, that philosophy didn’t carry through to the thermal system in the Mach-E.
Tesla’s approach, by contrast, is a masterclass in integration. Its “octo-valve” and “super manifold” consolidate thermal management into a compact, efficient package. With just a few hoses and two heat exchangers, Tesla minimizes weight, cost, and leak risk—all while improving thermal performance.
What’s more impressive? Tesla made this switch—from its earlier “super bottle” design—within a year. That kind of agile engineering is something Ford should take to heart.
Assembly Blunders and Oversights
Beyond the core design, we uncovered some puzzling manufacturing decisions. For instance, several holes appear to have been drilled post-assembly, complete with tags. These don’t seem to be part of the mold itself, suggesting a late-stage correction.
One insight helped make sense of it: apparently, Ford had to retrofit a child safety separator into the frunk after initially omitting it. That kind of regulatory oversight is expensive, not just in dollars but in lost reputation.
Adding insult to injury, we found a component labeled “scrap if dropped”—but no one on the team knows what it actually does. That kind of ambiguity has no place in a lean manufacturing environment.
Engineering Takeaways
From a design-for-manufacture standpoint, the Mach-E thermal system is overengineered and underoptimized. Here are the key takeaways:
- Too many parts: Every additional hose, connector, and pump increases complexity and failure points.
- Poor packaging: A stack of modules increases assembly time and weight while reducing serviceability.
- High leak potential: Spring clamps and COTS connectors are known risks, especially under thermal stress.
- Missed integration opportunities: Tesla’s octo-valve design proves a better approach is not just possible but practical.
Competitive Context: Where the Mach-E Stands
To Ford’s credit, the Mach-E’s system is a marked improvement over the company’s earlier ED4 architecture. It may also outperform similar systems found in the Polestar 2—though Munro hasn’t completed a full teardown of that vehicle yet.
Still, compared to Tesla, the Mach-E falls short. And in a market where EV buyers expect cutting-edge efficiency and reliability, that’s a problem.
Can Ford Catch Up?
For engineers, the Mach-E thermal system teardown offers a valuable cautionary tale. It underscores the importance of integrated systems, fast iteration, and relentless simplification.
Tesla’s ability to pivot quickly—from its earlier super bottle design to the current octo-valve system—demonstrates the kind of engineering agility needed to compete in the EV space. This redesign took less than a year. It wasn’t theoretical—it was executed at scale.
Ford should be asking: why not us?
Sandy challenges Ford to adopt similar lean design thinking as a running change—not only in the Mustang Mach-E but also in the F-150 Lightning. Both vehicles could benefit significantly from simplified thermal architecture, reduced component count, and a more integrated layout. It would lower cost, improve assembly times, and reduce the likelihood of quality issues like leaks or electrical connector failures.
While the Mach-E’s thermal system is an improvement over legacy systems like the ED4 and likely better than the Polestar 2 in some respects, it’s still overcomplicated. The opportunity to leap ahead is still on the table—but time is critical.
At Munro & Associates, we’ve helped legacy automakers like Ford make cost-saving pivots before—and we can do it again. As EV adoption accelerates and margins tighten, now is the time to embrace lean design and rethink outdated approaches.
Want more insights like this? Check out more Munro teardowns and stay informed on the cutting edge of automotive engineering.