Twitter user Greentheonly has made a habit of rooting through Tesla’s software and backend.After digitizing Tesla’s online parts catalog by the end of 2022, he came up with Parts diagram of the Tesla Semi Shows the arrangement of battery modules and some subsystems. Even better, there’s a sample VIN sticker that provides some of the numbers we outsiders are still waiting for. Starting at the upper left corner of the label, the Semi has a gross vehicle weight rating of 22,135 kg or 48,800 lbs. That’s not the weight of the Semi; like a car or a pickup truck, it’s the legally allowed weight of a Semi. The first column GAWR stands for Gross Axle Weight Rating. These three figures determine the maximum weight the Semi is legally allowed to carry on each of its three axles, which add up to the same 22,135 kg or 48,000 lbs as the GVWR.
When the tractor and trailer are pulled onto the scale, the scale ticket shows the weight on the front axle, called the steering, the combined weight on the two axles behind the cab, called the drive, and the combined weight on both axles of the trailer, called concatenation. On a standard ICE off-road truck, the limit is 12,000 lbs for the steerer, 34,000 lbs for the driver (17K + 17K), and 34,000 lbs (17K + 17K) for the tandem. That’s how you get the 80,000 max loaded weight most people are familiar with about road trucks. At 12,600 for the steering gear and 36,200 for the driver, the Semi weighs 2,800 pounds more than a conventional diesel-powered tractor.
Electric Class 8 trucks can gain an additional 2,000 pounds of gross weight when loaded, and can legally transport up to 82,000 pounds. Then, for the Semi, the 800 lbs used by the tractor over allowance will be deducted from the maximum legal weight the tandem can support. Two trailer axles can weigh up to 34,000 pounds when towed by a diesel tractor, and a trailer hitched to a Semi will be able to legally support a tandem of 33,200 pounds. It’s not trivial, but it’s not a deal-breaker without more context. We can only say that because the total weight of the tractor trailer may be under the legal maximum weight, but the weight of a set of axles exceeds the legal maximum weight – say a tractor trailer weighs 78,500 lbs, but it is impossible to let the driver or the less than 34,000 lbs Tandem – Perhaps the Semi’s greatest challenge was balancing the load in the 82,000-pound haul.
Bottom line: These numbers don’t tell us how much the tractor weighs, only how it distributes it. When hitched to a fully loaded trailer, a significant portion of the driver’s weight comes from the weight of the front end of the trailer and cargo located on or in front of the trailer.
brian king in next big future Created a chart comparing the Semi to other electric trucks. He allocated 26,000 pounds of tractor weight and 44,000 pounds of rated payload for the 500-mile Semi. He pegged the tractor weight for the 300-mile semi at 20,500 pounds and the payload weight at 46,500 pounds. In both cases, the total came to 70,000 pounds. We don’t know where those numbers came from, and Wang didn’t say.
Frankly, no matter how much parsing we do, it won’t matter until we get more information. Again we’re comparing the Semi to off-road trucks, which is not the Semi’s use case. As we’ve said before, a Semi is a day taxi designed to deliver goods on short regional routes, and day taxis typically don’t load up to the federal maximum. But the Semi looks like a road truck, and Tesla keeps talking about it being like a road truck, so it’s often compared to a road truck.
Moving on to the other goodies in the treasure trove, the drawings show a modular battery arrangement with nine battery packs under the cab floor. There is an image of a super cooling module at the charging port to keep the temperature low during megawatt charging. Tesla has a cute name, driver torque and efficiency. Torque is the one closest to the cab, and its two motors fire up for acceleration and re-pulling, and Efficiency’s single motor runs on its own during steady-state cruise.