It's going beyond hydrogen-electric hybrids.
23 demo units will enter two fleets in California in 2019.
"We are estimating that we could have pay back within a year-and-a-half based on energy usage as well as lower maintenance cost," says DHL executive Jim Monkmeyer.
Fortigo Freight Services in Canada will also test the Tesla Semi.
In response to a Tesla customer asking if he would get his car delivered this year, Musk tweeted, "December will be a big month, so probably, but it is impossible to be certain right now."
Volkswagen is content being a "second mover, who would rather check a couple of times more whether the standards are right."
Nikola Motors, the Tesla of the trucking world, claims $2.3 billion dollars in pre-orders for its plug-in semi. The Nikola One is a near zero-emissions semi truck that utilizes a natural gas-electric hybrid system.