If you ask the Tesla engineers behind Cybercab to sum up its design in one rule, the answer is these four plain words: "donot waste a gram" 🔥 It sounds like a simple rule about using less. But the closer you look, the smarter it gets 🔥 ✂️ WHAT $TSLA DELETED Model 3 and Model Y surround their battery electronics with a separate wall, top cover, seal, and a handful of bolts. Cybercab replaces all of that with a single stamping, and that same battery cover doubles as the car's floor. The heat pump's compressor bolts straight onto the refrigerant manifold, wiping out every refrigerant hose in the system. And instead of running dedicated high-voltage circuits from the battery to the thermal system, Cybercab simply taps power from the drive inverter, which already carries high voltage. The electric oil pump is gone, along with its circuitry and firmware, replaced by a simple mechanical one. So is the one-shot pyro fuse. The front and rear body modules even skip e-coating, part of eliminating a paint shop that can cost a few hundred million dollars to build. Even fun gets audited. Tesla's head of drive units isn't a fan of Easter eggs, because someone would have to spend time grinding a logo into a die that never needed one. As a colleague put it, if it adds a penny, it's too much. ⚖️ SPENDING A LITTLE TO SAVE A LOT Here's the twist. Sometimes not wasting a gram means adding one. Every battery module board now gets a wireless chip, adding 20 to 30 cents to its cost. In exchange, Tesla deletes a communications harness that might cost about a dollar, plus roughly 50 cents to install. Robots hate harnesses too, because they're notoriously messy to automate. The battery enclosure switches to steel, which costs about $1.90 per kilogram versus $5 to $8 for aluminum. To get it down to just 1.2 millimeters thick, engineers add local reinforcements and extra parts exactly where they're needed. Steel loses on weight, but Tesla says the numbers still come out ahead on cost. The motor's cooling passages move out of pricey electrical steel and into the cheaper die-cast aluminum surrounding it. Every job goes to the cheapest material that can do it well. 🏋️ THE WAR ON HIDDEN PADDING Padding is one of the sneakiest ways a car gains weight. If the target is 1,600 kilograms, every team designs to 1,600. The car still has to meet every requirement, but no team gets to slip in its own 20% cushion on top. Testing works the same way. Parts are expected to fail between 95% and 100% of their spec, because a part that survives far beyond it is hauling around material it doesn't need. That matters because weight snowballs. A heavier car needs bigger brakes and a stronger structure, which pile on even more weight. The good news is that efficiency snowballs too. Cybercab turned out more efficient than Tesla expected, so the pack needed fewer cells than planned, leaving spare room inside. ♻️ WASTE IS MEASURED OVER A LIFETIME The rule doesn't stop at the factory door. Battery modules are now potted individually instead of as one solid pack. If one module fails, three healthy ones worth about $1,500 each get saved. On a Model Y structural pack, that same failure means replacing the whole thing. Reusable contactors can cut power under load a few times and keep right on working, so a minor fender bender doesn't have to blow a one-shot fuse and send the car to service. We usually judge a car's efficiency the day it rolls out of the factory. Tesla is judging Cybercab on the day it finally retires, at least half a million miles later, and counting every gram it never had to replace.