Tesla’s push for efficiency doesn’t just happen in software — it starts with the scale. In a recent discussion with Car and Driver, Tesla’s Vice President of Vehicle Engineering, Lars Moravy, pulled back the curtain on how the company managed to remove close to 400 pounds from the Model X over the years, all while keeping performance, range and safety intact.
According to Moravy, Tesla’s relentless focus on mass reduction is deeply rooted in its engineering culture. He even joked that his engineers were rewarded with a case of beer for every kilogram shaved off the vehicle — and by the end of the project, a lot of beer had apparently been purchased.
“Not a joke. Mass is serious. I really do care that much. Mass is everything, safety, efficiency, attributes (like NVH), energy, consumption, cost, EVERYthing. If you don’t care about mass you don’t care about your customer,” Moravy explained in a post on X.
Weight Reduction by a Thousand Cuts
The roughly 400-pound reduction didn’t come from one massive redesign, but rather hundreds of smaller improvements spread throughout the vehicle.
One of the biggest changes came from the powertrain. Tesla replaced the rear induction motor with a permanent-magnet design and optimized the half-shafts, resulting in a weight savings of around 100 pounds alone.
The battery pack also saw a major overhaul. While the total capacity remained the same, Tesla redesigned the pack using denser cells, vertically arranged modules, and around 300 fewer cells combined with structural improvements. That effort removed roughly 90 pounds from the vehicle.
Interior changes contributed significantly as well. Through updated components, new manufacturing techniques, integrating airbags into the headliner fabric, and revising seat configurations, Tesla managed to cut another 80 pounds while still enhancing the premium feel of the cabin.
Weight savings extended even into the wiring. By optimizing the high-voltage system and replacing copper with aluminum, engineers reduced mass by about 44 pounds. Meanwhile, Tesla simplified the cooling system, shedding another 30 pounds.
Structural improvements also played a role. New, larger front and rear megacastings reduced parts complexity — going from eight major components to just four — while saving over 20 pounds and increasing torsional stiffness by 10 percent.
On top of that, Tesla introduced a new lithium-ion 12-volt battery, trimming 14 pounds. Suspension revisions saved another 10 pounds, thinner plastic exterior fascias cut 10 more, and a newly designed cast refrigerant manifold eliminated an additional 3 pounds.
Why Weight Matters So Much
For Tesla, this isn’t just about hitting a smaller number on the scale. Reducing mass improves efficiency, handling, braking, and even safety. Lighter vehicles require less energy to accelerate and maintain speed, which directly translates into better real-world range and lower operating costs for owners.
Moravy summed up Tesla’s mindset perfectly, referencing a favourite internal saying: “Mass begets mass” — meaning that every pound removed helps prevent more unnecessary weight from creeping back in later.
“Hats off to the team that cut all that mass AND made a better and less expensive car. Engineers, factory, and supply chain at work!” he added.
As Tesla continues refining its vehicles, the Model X weight-loss story shows that sometimes the biggest improvements come from dozens of small, carefully engineered decisions — and a company culture obsessed with making every gram count.
