Tesla’s All-Electric Semi Sounds Amazing—But How Much Will It Cost, Exactly?

Elon Musk wants big rigs to trade their diesel for electrons. Last night, the Tesla CEO unveiled his hotly anticipated truck (and decided to throw the announcement of a new $200,000 super car in for good measure). The Verge has a nine-minute highlight reel of the event, in case you’d like to watch the grand unveil yourself.

The real news here isn’t the car, even if it will go from 0 to 60 miles per hour in 1.9 seconds—it’s the electric tractor-trailer, which has been the source of much speculation since Musk announced its development last summer. To hear him speak, you would be compelled to think that this is the future of trucking. Or at least it will be when it launches, which is expected to be in 2019—though the firm isn’t exactly known for punctuality.

Frankly, it sounds too good to be true: the claim is that it will go 500 miles on a charge, hit 60 miles per hour three times faster than a regular truck when fully loaded, power up a 5 percent gradient at 65 miles per hour, drive itself most of the time using Autopilot—and cost just $1.26 a mile to run, versus $1.51 for a diesel. (Those running costs could actually be lower, too, if the trucks were platooned, one behind the other, to cut drag.)

But perhaps it is too good to be true? Tellingly, Musk didn’t name a price for the semi, only quipping that “Tesla stuff is expensive” to a fawning crowd, according to the New York Times. Fortunately, people have already thought about the cost of electric trucks, and an analysis published in ACS Energy Letters recently suggested that such a vehicle capable of covering 600 miles would need a battery pack that costs as much as $400,000, before the rest of the truck is considered. That compares with around $120,000 for a regular diesel truck, all-in.

Even with Musk’s claimed 25-cents-per-mile saving (which, to make good, requires a source of wholesale electricity at a faintly ridiculous 7 cents per kilowatt-hour), those numbers still mean that Tesla’s semi would need to drive in the region of a million miles to break even against a diesel truck. And that’s surely going to prove a hard sell, however much it’s helped along by the warm and fuzzy ethical feeling of going electric.