What to expect from Tesla's 'D' event

When Elon Musk takes to Twitter for a tease or two, you know it's going to be good. Here's what you can look forward to on Thursday.

Tim Stevens Former editor at large for CNET Cars
Tim Stevens got his start writing professionally while still in school in the mid '90s, and since then has covered topics ranging from business process management to video game development to automotive technology.
Tim Stevens
3 min read

What is the mysterious Tesla D? Tesla

Elon Musk's mysterious (and unintentionally suggestive) tweet last week left many wondering what the Tesla "D" will be -- and indeed what might be the "something else" he teased. But we've got a pretty good idea of what the Tesla Motors CEO will unveil on Thursday.

The AWD Tesla Model "D"

Yes, there is a new Tesla coming soon, but it isn't as new as you might think. Tesla has been testing an all-wheel-drive version of the Model S for some time now, both to fill a need for consumers and also acting as something of a test mule for the upcoming Tesla Model X SUV.

AWD car sales have surged 79 percent since 2009, according to an IHS Automotive study, which also states that in 2013 more than half of all BMWs sold spun all fours, while a whopping 93 percent of Audis do the Quattro thing. These are exactly the brands that Tesla has in its crosshairs, and it needs an all-wheel-drive sedan to truly compete.

A traditional AWD system relies on a series of differentials, clutch-packs, driveshafts and plenty of other spinning bits that add weight, complexity and cost, largely thanks to the need to take power from a single source (the gasoline engine) and spread it as evenly as possible across all four wheels.

Electric cars open the door to more novel solutions, with some manufacturers choosing to simply put one small motor at each wheel. The Model S currently relies on a single motor to drive both rear wheels, and everything I'm hearing is that the new D model will put a second motor up front -- the "D" possibly meaning "dual" in this case. This alone could add about another 150 pounds to the weight of the car, plus a fair bit on top for the reduction gears, the two additional half-shafts required to spin the wheels and, of course, the wiring and circuitry to feed it power.

This will impact handling to some degree, and likely will also impact range -- though not as much as you might think. Having twice as many motors doesn't mean twice the power consumption, as each one will be called upon to do less work. In fact, Tesla could consider using smaller motors front and back while still delivering the same effective performance.

More details on Model X

Model X Tesla

Tesla's swing-wing SUV, the Model X, has been making the rounds for years now, facing a series of delays as the company's engineers have struggled to make the necessary revisions to the Model S chassis and drivetrain. If they're announcing an AWD version of the Model S, it's safe to assume they've figured out enough to give us a lot more information on the Model X.

While proudly showing off the exterior of the vehicle, there's still a lot we don't know about the Model X. Details like range, power, weight and, perhaps most importantly, cost. Look for a lot of those questions to be answered Thursday.

The lower-cost Model 3

As the Model X has been delayed so, too, has been the Model 3, the long-awaited EV from Tesla that would be affordable -- or more affordable than the Model S, anyway. The Model X is still the main focus for the company, but with that getting closer to release it might just be time for Tesla to give us more information about the vehicle -- if only just a rendered glimpse.

More driver assists

Elon Musk recently made headlines when he promised that Tesla would have "90 percent" autonomous cars on the road by next year. He's also been aggressively hiring engineers to work on the program, including poaching quite a few from Volvo's self-driving research program.

That's despite Tesla's Model S being one of the most limited cars on the road when it comes to driver aids. Basic stuff like adaptive cruise control, which speeds up or slows down based on traffic, isn't even available as an option. Meanwhile, it's standard fare on many far less expensive cars.

While expecting a demonstration of a Model S is probably aiming too high, we're hoping to see some updates on the driver assistance front on Thursday.