According to a series of tweets from Tesla boss Elon Musk, the electric car manufacturer plans to expand its lineup with a semitruck. The big-rig aspirations are outlined in Musk’s master plan, which also says the company wants to follow up its semi with a consumer pickup and eventually a sports car. Even if you had read Musk’s manifesto, Tesla’s September unveil of the semi would be a surprise. It’s likely the truck will have more advanced autonomous features than those found on current production Teslas. According to Ben Kallo’s interview with Bloomberg, expect it to be, at the very least, semi-autonomous. That might be scary for some, but the concept of a fully autonomous rig isn’t new. Last year, autonomous trucking startup Otto delivered a trailer full of beer without too much human interaction.