A few days ago Tesla Motors announced a new Ludicrous Mode for the Model S.

While working on our goal of making the power train last a million miles, we came up with the idea for an advanced smart fuse for the battery. Instead of a standard fuse that just melts past a certain amperage, requiring a big gap between the normal operating current and max current, we developed a fuse with its own electronics and a tiny lithium-ion battery. It constantly monitors current at the millisecond level and is pyro-actuated to cut power with extreme precision and certainty.
That was combined with upgrading the main pack contactor to use inconel (a high temperature space-grade superalloy) instead of steel, so that it remains springy under the heat of heavy current. The net result is that we can safely increase the max pack output from 1300 to 1500 Amps.
What this results in is a 10% improvement in the 0 to 60 mph time to 2.8 secs and a quarter mile time of 10.9 secs. Time to 155 mph is improved even more, resulting in a 20% reduction.
This option will cost $10k for new buyers. In appreciation of our existing P85D owners, the pack electronics upgrade needed for Ludicrous Mode will be offered for the next six months at only $5k plus installation labor.

You might wonder why Tesla would even bother releasing a $10,000 upgrade that buys you 0.3 seconds in your 0-60 time. Ludicrous indeed, right? I supposed it could be justified as just a publicity stunt, and it did garner more press than the other announcements they made, but I believe it just emphasizes just how critical it is to Tesla's success to show that going electric does not mean any sacrifice in performance. In many cases they now tout electric cars as a superior experience to ICE cars.

I don't think Tesla would have succeeded any other way except by starting with a high end performance car and then moving down market. At the time their first model the Roadster was released, electric cars were almost all hybrids, and the pure electric cars that were on the market had really low range, in the neighborhood of 80 miles on a full charge, so they were of necessity second or third cars for people with short commutes. The cars were very underpowered; it wasn't a stretch to say electric cars were like glorified go-carts.

There were very few public chargers, if any, and installing a charger at home was a costly upgrade from the electric company, if it was even available in your area. Electric cars were toys for a sliver of the wealthy.

The Roadster, but more the Model S, was the first electric car to credibly stand in as both a practical and sexy alternative to ICE cars. When it was first announced, there were still very few public chargers, and even today the public charging situation is meager when compared to the number of gas stations. Going electric would still be a sacrifice for many drivers today.

That is why the performance of the Model S in other respects was so critical. The battery life for high end models, around 260 miles on a full charge, was finally enough for more than just a short daily commute (it's not surprising to me at all that most of the sales of the Model S have been for the largest battery, to the point where they dropped the low end model). Battery life was critical to the first iPhone's appeal, and it's even more critical to electric cars because of the limited charging infrastructure.

The styling of the car was a fine balance between conservative and overly aggressive. No matter what you think of it, though, it didn't scream economy car like most compact electric cars before it. The designer came from a background designing European luxury cars, and the lines of the car evoked those more than boxy economy cars.

The 0-60 performance was a thrill then, and it's absurd now. Ludicrous, you might say. I test drove a P85D with insane mode turned on and the acceleration from a standing stop to 60 miles per hour was so extreme I felt dizzy and had to pull over for a few seconds to regain my equilibrium. It's like nothing you've ever felt before unless you're the circus clown they shoot out of a cannon. That so many YouTube videos showed the Model S dusting BMW's, Audi's, Porsches, Ferraris, and Lamborghinis on race tracks underlined the fact that you were sacrificing no performance whatsoever in going electric. In fact, you could now be the fastest kid on the block.

Add all of that up to other talking points like the giant touchscreen and ample storage space and what the Model S did was unlock the ability for relatively wealthy people to signal their concern for the environment without sacrificing anything in driving performance or personal style. It's an expensive signal, but as any knowledgeable sociologist or economist might tell you, the more extreme the signal, the clearer the signal. Driving a Ferrari down the street is a clearer signal than a BMW. The giant tail feathers of a peacock? Ludicrous, perhaps, but a very efficient signal.

Before the Tesla, owning an electric car marked you as an eccentric, a hippie even. Tesla singlehandedly changed the signaling potential of the entire electric car category.

Given the unfriendly car charging context into which Tesla had to launch its electric cars, this is not a market where low end disruption would have worked. The cost of batteries just didn't put that type of price/performance strategy in play. Tesla shook up the market by attacking the high end, luxury car market, just as they had to, and to compete in that segment, sometimes you have to pull up along side the ICE sports car at the stoplight and blow it off the line. Sometimes, the way to achieve escape velocity is by achieving a lot of velocity.

Fitt's Law, the Tesla Model S, and touchscreen car interfaces

Fitts’s Law can accurately predict the time it will take a person to move their pointer, be it a glowing arrow on a screen or a finger tip attached to their hand, from its current position to the target they have chosen to hit.

Much more about Fitt's Law here from Tog. This bit was instructive:

Paul Fitts was not a computer guy.  He was working on military cockpit design when he discovered his famous Law. Paul Fitts never had to deal with the the issue of stability because stuff inside aircraft cockpits is inherently stable. The few things that do move only do so because the pilot moved them, as when he or she pushes a control stick to the side or advances the throttle forward.  The rest of the targets the pilot must acquire—the pressure adjustment on the altitude indicator,  the Gatling gun arm switch, the frequency dial on the radio, and fuel pump kill switch—stay exactly where they were originally installed. Everything in that cockpit is a predictable target, either always in the same place or, in the case of things like the throttle, within a fixed area and exactly where you left it. Once you become familiar with the cockpit and settle into flying the same plane hour after hour after hour, you hardly look at your intended targets at all. Your motor memory carries your hand right to the target, with touch zeroing you in.

I had heard of Fitt's Law but didn't know its history, and it came to mind as I was driving my Tesla Model S recently.

In almost every respect, I really love the car. I took ownership of my Model S in December 2012 after having put down a deposit over 3.5 years earlier, and I long ago stopped thinking of it as anything other than a car, perhaps the most critical leading indicator as to whether it can cross the chasm as a technology. I've forgotten what it's like to stop and pump gas (what are gas prices these days anyway?), it's roomy enough I can throw my snowboard, road bike, and other things in the back with room to spare, and I still haven't tired of occasionally flooring it and getting compressed back into my seat like I'm being propelled by a giant rubber band that has been released after being stretched to its limit. Most of all, it's still a thrill when I fire the car up to find a new software update ready to install, almost as if the Model S were a driveable iPad.

It's the ability to update the interface via software that gives me hope that a few things in the interface might be adjusted.* In a Model S, most of the controls are accessible via a giant touch screen in the center of the console. There aren't many buttons or switches except on the steering wheel which you can use to handle some of the more common actions, like changing the thermostat, adjusting volume on the sound system, skipping ahead on a musical track, and making phone calls.

When the car first came out, one of the early complaints was the lack of physical controls. I was concerned as well. Physical controls are useful because, without looking at the road, I can run my fingers across a bunch of controls to locate the one I want without activating the wrong ones by mistake as I search. With a touch screen, there is no physical contour differentiating controls, you have to actually look at the screen to hit the appropriate control, taking your eyes off of the road.

[I also confess to some nostalgia for physical controls for their aesthetics: controls in a car give physical manifestation to the functionality of a car. The more controls a car has, the more it appeals to geeks who love functionality, and physical controls also give car designers the opportunity for showing off their skills. I find many old school car dashboards quite sexy with all their knobs and switches and levers. Touch screens tend to hide all of that which has more of a minimalist appeal that may be more modern.]

In practice, I have not missed them as much as I thought I would because a lot can be operated by physical controls on the steering wheel.

However, one task that a touch screen makes difficult, in practice, is hitting a button while in a car that's in motion. It turns out that road vibration makes it very hard to keep your arm and hand steady and to hit touch targets on a touchscreen with precision. That's why I rely so much on my steering wheel controls in the Model S to do things like adjust the volume or change the temperature. Not only are the controls accessible without having to move my hands or look at the touchscreen, but the steering wheel acts as an anchor for my hand, taking road vibration out of the equation.

Maybe there is an analogue to Fitt's Law for touch screens interfaces in cars or other places where your body is being jostled or in motion. What you'd like is maximum forgiveness in the UI in such cases because it's hard to accurately hit a specific spot on the screen.

Matthaeus Krenn recently published a proposal for touch screen car interfaces that takes this idea to the logical extreme. You can read about it and watch a video demo as well. Essentially Krenn transforms the entire touchscreen in the Tesla into one single control with maximum forgiveness for your fingers to be jostled horizontally since only the vertical movement of your hand matters. By using the entire screen and spreading the input across a larger vertical distance, you can have a much larger margin of error to get the desired change. Krenn also tracks the number of fingers on the screen to allow access to different settings.

This is an interesting proposal, but for some of the most accessed functions of the car, controls on the steering wheel are still superior. The left scrollwheel on the Model S steering wheel is more convenient for changing the volume of the stereo and toggling between play and stop (you can press the scrollwheel) than the touchscreen. The right scrollwheel is more convenient for changing the car temperature and turning the climate control on and off than the touchscreen. Both scrollwheels allow you to keep both hands on the steering wheel rather than having to take the right hand off to access the touchscreen.

Actually, the ideal solution to almost all of these problems is a combination of the steering wheel controls and another interface that already exists in the car: voice. The ideal car interface from a safety standpoint would allow you to keep your eyes on the road and both hands on the steering wheel at all times. The scrollwheel and steering wheel buttons and voice commands satisfy both conditions.

In the Model S, to issue a voice command, you press and hold the upper right button on the steering wheel and issue your voice command, after which there is a delay while the car processes your command.

Unfortunately, for now, the number of voice commands available in the Tesla Model S are quite limited:

  • Navigation — you can say "navigate to" or "drive to" or "where is" followed by an address or destination
  • Audio — you can say "play" or "listen to" and then say an artist name or song title and artist name and it will try to set up the right playlist or find the specific track using Slacker Radio (one of the bundled audio services for Model S's sold in the U.S.)
  • Phone — if you connect a phone via Bluetooth, you can say "call" or "dial" followed by the name of a contact in your phone contact book

I'm not sure why the command list is so limited. When I first got the car I tried saying things like "Open the sunroof" or "Turn on the air conditioning" to no avail.

Perhaps the hardware/software for voice processing in the car aren't powerful enough to handle more sophisticated commands? Perhaps, though it seems like voice commands are sent to the cloud for processing which should enable more sophisticated voice processing when you have cellular connectivity. Or perhaps the car can offload voice processing to select cell phones with more onboard computing power.

In time, I hope more and more controls are accessible by voice. I'd love to have voice controls passed through to my phone via Bluetooth, too. For example, I'd love to ask my phone to play my voicemails through the car's audio system, or read my latest text message. For safety reasons, it's better not to fiddle with any controls while driving, analog or touchscreen-based.

Perhaps this is a problem with a closing window given the possibility of self-driving cars in the future, but that is still a technology whose arrival date is uncertain. In the meantime, with more and more companies like Apple and Google moving into the car operating system space, I hope voice controls are given greater emphasis as a primary mode of interaction between driver and car.

* One other thing I'd love to see in a refresh of the software would be less 3D in the digital instrument cluster above the steering wheel. I have some usability concerns with the currently vogue flat interfaces in mobile phone UI's, but the digital instrument cluster in a car is not meant to be touched, and the strange lighting reflection and shadow effects used there in the Tesla feel oddly old-fashioned. It's one interface where flat design seems more befitting such a modern marvel.

Tesla battery swap

You can swap a new battery into your Tesla Model S in 90 seconds. Here's the proof.  No details yet as to how much they'll charge for a battery swap. It sounds like if you keep the new battery you pay the difference, perhaps charged based on battery age and capacity differences.

I have done one long road trip so far, from San Francisco to Los Angeles and back, and I stopped at all 3 supercharging stations between the two cities in each direction. It added about a two hours to my trip in each direction because the first supercharging station was packed on the way down, and I couldn't find an open station to charge at in Los Angeles before hitting the road on the way home. 

The next time I make the road trip, I hope to try the battery swap, not just to satisfy my curiosity, but to save on time. Since that trip they've also issued a software update for the car that now shows charging stations you've visited and Tesla supercharging stations on the onboard maps. 

As with owning something like an iPhone, it's always fun when the product improves over time.  Usually it's because of software updates, but a battery swap is really a hardware upgrade.

I guess this obviates the need for someone like Mophie to make a $5,000, 250-pound external battery pack for the Tesla.