@JonMc Maybe the Semi will allow pluggable batteries such that if your Trucking Company owns 10 trucks you could purchase them with "standard range" (300mi?) and rent extra battery packs for longer trips, which can extend the range to 600mi or 900mi, when necessary. This would be the Tesla "Semi Battery Swap Rent" concept
Who calculates the range? Tesla, it seems. That doesn't give us a lot of insight, as they can bias it any which way they like. The EPA doesn't seem to rate ranges (though it has a heavy-duty cycle). From all I can find, Tesla has only said this regarding the Semi's range: Long-range is likely long-haul. But long-haul is anything over 150 miles, according to the Federal Motor Carrier Safety Administration. That is, long-range in trucking parlance seems different than what we consider is long-range in a consumer automobile. And highest weight capability? That's just...any semi you've ever seen. The Ford F-650 is a class 6. Class 8 is pretty much any and every semi. Class 9 exists, but it does not include any higher weight limits, but maybe Tesla will call it Class 9 to make it sound better. Even a typical "250-mile" semi will fully validate Elon's claims. All rumors and leaks point towards a 200 to 400 mile range. I don't expect any Megawatt-Hour batteries, like we initially thought.