Get ready for Tesla to grow up

Sunday is a favorite tweet day for Tesla CEO Elon Musk, and this past weekend he fired off a tweet that defied everyone who thinks the electric carmaker is tapped out on market-moving news and announcements for the rest of the year.

Tesla will unveil something on October 17, and the soon-to-merge Tesla and SolarCity will follow on October 28.

Focusing only on the Tesla side of things: I'm pretty sure we're going to see the crossover SUV version of the mass-market Model 3 sedan, which was showcased in prototype form earlier this year.

Here's why this will be a excellent sign for Tesla, heading into 2017 and the launch of the $30,000-ish (after tax credits) Model 3: it will show that the automaker can easily build more than one vehicle off a versatile platform.

Tesla's first three vehicles were essentially bespoke undertakings. The Roadster used a framework borrowed from Lotus; the Model S sedan was a clean-sheet design; and the Model X SUV was based on the Model S platform, but it was highly "customized" in the sense that it served up a variety of radical - and complicated - design elements, from "falcon wing" doors to a large windshield.

Tesla isn't Ferrari and doesn't want to be, so this design and engineering approach has to go if it hopes to become a carmaker of scale, meeting Musk's goal of 500,000 in annual vehicle production by 2018.

Platform engineering

There's never been any question that the Model 3 - which will be the basis for the inevitable compact crossover, called by Musk the "Model Y" - would be Tesla's first true foray into what's known in the auto industry as "platform engineering." Outside the most exotic vehicles, the days when every car was hand-built and mechanically distinctive are long gone. Car companies now use a relatively small number of platforms to deliver all sorts of different types of vehicles. This practice allows for much greater manufacturing efficiency and better use of capital.

Tesla is growing up - literally. It aims to go from 80,000 to 90,000 deliveries, on roughly 100,000 vehicles produced, in 2016 to half a million by 2018. With around 375,000 Model 3 advance orders already taken, the bulk of that production will have to be on the mass-market front.

Small sedans aren't exactly unpopular, but there is a view in the industry that passenger cars are going to lose out long-term to SUVs. Tesla has already made this mistake once, launching the rear-wheel-dive only Model S just as the SUV market in the US was starting to regain strength. A patch arrived when the all-wheel-drive, dual-motor trim level arrived in late 2014. However, it took too long for the Model X SUV to join the lineup; by its launch in 2015, Tesla was already lagging in the SUV market, electric-powered of otherwise.

Musk doesn't ever want to make that mistake again.

But then again ...

And that raises another tantalizing set of possibilities. It makes sense to roll out the Model Y design and possibly even suggest that it could hit production at about the same time as the Model 3. That could set off another riot of pre-orders.

But Tesla could also be planning to show a couple of new vehicles that will ultimately use the Model 3 platform: a new Roadster; and a pickup truck.

A fresh Roadster would send Tesla's earliest loyalists into a frenzy. The old car is great, but it's also rather uncomfortable, not very versatile, and it lacks much of the cool interior tech that one can get on the Model S and X. Owners have had to make do. But maybe they kept a Porsche 911 around, in case they didn't want their bones rattled quite as much.

A pickup truck would be mind-blowing. It would also exploit an unexpected revival of small pickups in the US, as General Motors has been quite successful with it mid-size Colorado.

Finally, Tesla needs to make some news. After its best quarter ever for deliveries - 24,500 in Q3 - was met with a weak response from Wall Street, Musk and his team need to rally the financials, even if Musk now says additional capital raises on the public markets won't be necessary.

Creating a few prototypes of what will form the core of Tesla's mass-market portfolio is actually a simple way to do this. Tesla will then clearly have a "luxury" lineup with the Model S, X, and possible the new Roadster; and it will have vehicles destined for all the important mass-market segments: mid-size sedan, compact crossover SUV, and pickup truck.

Tesla is about to officially join the big leagues. And that would be some October surprise.