Yesterday, electric-car maker Tesla Motors (TSLA 1.85%) took the wraps off its next software update, version 6.2, while also teasing an update due in "about three months" that will give the Model S the ability to steer itself from highway on-ramp to highway off-ramp.

Model S owners control the evolving Tesla software on a 17-inch touchscreen. Image source: Tesla Motors.

Tesla held a press conference to announce the update rather than quietly rolling it out to customers, as it has often done in the past. This marks a clear effort to make a statement to the world about its cars. That message was highlighted in a Tesla blog post yesterday:

Most cars don't improve over time. By contrast, Model S gets faster, smarter, and better as time passes. With Tesla's regular over-the-air software updates, Model S actually improves while you sleep. When you wake up, added functionality, enhanced performance, and improved user experience make you feel like you are driving a new car. We want to improve cars in ways most people didn't imagine possible.

The breadth of the updates Tesla is planning is impressive, demonstrating why the company calls its Model S "a very sophisticated computer on wheels." Here's what you need to know.

Version 6.2
Tesla will begin delivering version 6.2 to customers via an over-the-air update within the next nine days. The two most prominent features of the software update are Range Assurance and Trip Planner -- both purposed to "eliminate range anxiety entirely," according to Tesla.

Tesla's Trip Planner demonstrated. Image source: Tesla Motors.

Trip Planner, true to its name, simply navigates Model S owners through the most optimal route of charging locations when they select their destination. The route the software selects will aim to minimize driving and charging time. When charging, owners will receive notifications on their phones when their vehicles have charged the appropriate amount to reach their next destination.

Range Assurance operates in the background, Tesla said, "continually monitoring and advising owners when they are at risk of driving beyond the range of reliable charging locations."

Also new with version 6.2, Tesla will add its Destination Charging locations into the Model S's onboard navigation system. These facilities charge vehicles significantly slower than Supercharger stations do but are growing in number daily. Tesla's Trip Planner and Range Assurance systems will consider Superchargers, Tesla Destination Chargers, and previous locations where an owner has charged when trip-planning and range-assuring. The software will favor faster charging over slower charging.

Furthermore, Tesla's range prediction system, a feature rolled out in version 6.1, will be much more accurate. Currently, Tesla's range prediction takes into account speed and elevation changes in predicting Model S range. But version 6.2 will also give weight to weather and wind speed data. Tesla CEO Elon Musk said during the press conference that the improved software will predict range within 1% accuracy.

Other new key features in the update include automatic emergency braking, blind spot warning, and valet mode. Automatic emergency braking and blind spot warning will only work for Model S with new autopilot hardware, which Tesla began including standard on its vehicles in the second half of September 2014. Valet mode, which discreetly limits Model S's driving performance and restricts access to personal information, the glove box, and the front trunk, will be enabled on all Model S's.

Auto-steering on highways
Looking out a bit further, Tesla said that in a few months it will send an over-the-air update to its Model S with autopilot hardware that will turn on auto-steering.

"We can basically go between San Francisco and Seattle without the driver doing anything," Musk said during its press conference Thursday. Combined with the company's adaptive cruise control that was already reading speed limit signs and controlling the accelerator and brake pedals on the highway, Model S owners will now be able to drive between highway entrances and exits without touching any inputs.

Even lane changes will eventually be automatic for Model S. Tesla said its new hardware will enable the car to automatically steer during a lane change (when it is safe) after the owner turns on the turn signal. Image source: Tesla Motors.

Tesla's increasingly rapid rollout of improving software for the Model S is outpacing all other automakers' efforts. The significant updates to Tesla software highlight just how important software is to its approach to building electric vehicles.

Tesla is about more than batteries and electric motors: This Silicon Valley-based company is as much of a software company as it is a manufacturer.