Talking about cars in general and electric cars in particular, you are bound to get around to the subject of the launch from 0–60 mph acceleration every now and then. And frankly, it doesn’t really make sense in daily life, does it? The recent hype about the new Tesla Roadster proves the point. I mean, 0–60 in 1.9 seconds? Really? You would need a medical clearance for doing that. I get blurry vision below 4 seconds, so what’s the point? Apart from getting home in time for lunch — sorry, couldn’t help myself with the title of this post. 😉
The Devil Is In The Detail
Anyway, I was watching Chris Harris playing around with the Tesla P100D in this great Top Gear post. And even though the guys at Top Gear are generally skeptical about what Tesla is offering, I think Chris made some excellent points. The fact that this was his first ever ride in a Model S made it very entertaining.
To have an adequate reference to the P100D, a Porsche 911R was lined up for the show. What a beautiful and legendary car that is. Just imagine if Porsche succeeds in getting all that driving DNA embedded in the new Mission-E — they really have to, right?
So, for me and you, it was of course no surprise that the Tesla family sedan left the Porsche in the dust from standstill, and it was neither much of a surprise that the Porsche roared past the Tesla at 130 mph. The nice surprise was how well the footage explained how the Tesla is able to launch that fast — or rather, why a car with an internal combustion engine, clutch, gears, and differentials will never be able to launch as fast as an electric rival.
The Chain of Action & Reaction
I won’t get into numbers about torque and horsepower here, because these two speed machines just have all of that in stupendous abundance. Period. Had it not been for the electronics, these cars would do nothing but burn rubber all the time. Not to mention the price of a pair of tires on that Porsche … which is completely irrelevant if you can afford the car in the first place. Okay, I will get on with it…
Porsche Chain of Power Details
Let’s begin with the Porsche. In this short clip from the Top Gear video (time 5:15) it is clear that a lot of things are going on. The rear wheels are struggling to keep from slipping on the tarmac. Sensors on the spindle and hub of the wheels are feeding the car’s computers with information about wheel position and rotation speed and it is very clear that multiple times each second power is fed and cut in a vicious cycle of trying to get all that power to the ground in order to create forward movement. Look at the body parts of this solidly built machine. All wobbly. The exhaust system looks as if it could fall off any moment. Still, this car is wicked fast.
Tesla Chain of Power Details
And then the Tesla. In this short clip from the same Top Gear video (time 3:00) nothing is apparently going on. It is only because we know that this 2 ton car will reach 60 mph in 2.4 seconds that a lot of things must be going on. I really don’t know how Tesla has managed to control the rubber-to-tarmac exercise to this incredible degree. But I do know that the chain of fuel injection, ignition of vaporized fuel, forcing of pistons, smoothing of torque by flywheel, transferring torsion through a clutch, and adjusting engine revolutions to maximize torque with a gearbox have all been removed. Instead, the electric power fed into the alternating current electric motors is converted to magnetic fields that force a rotor to produce torsion that is only one or two fixed reduction gears away from the tarmac surface. This chain of power delivery is adjusted hundreds of times per second, which is why the video shows nothing. Thus, the secret behind the highly efficient conversion of stored electrical energy to kinetic energy is not revealed.
Please, tell me why is this important?
Well, I really had no intention of rambling on about high-performance cars. I like watching loads of videos like this one on Engineering Explained and read loads of articles like this great one on Motor Trend explaining these things in the nerdiest possible way, just for the fun of it. But when I looked closer at the Top Gear video, I understood that we are truly witnessing a profound shift in transportation technology.
This is not only about performance in the sporty sense. It has a lot to do about performance in terms of safety too. This shows us very clearly that the cars of the new electric era are capable of much more than their fossil-fueled counterparts in regard to things like emergency braking, collision avoidance, grip on less than optimal road conditions, general track stability, etc. And since the chain of power from fuel source to road surface is so short in EVs, and the computers being fed with data from a huge arrays of sensors are getting so powerful, the probability of serious accidents are in steep decline.
The importance of all this is obvious in autonomous vehicles, but I am pretty sure that manually driven cars (or should I say: cars driven in manual mode) will be a ton of fun in the future. Which is fortunate for Chris Harris and the guys at Top Gear, so that they can keep producing these eye-candy videos for the rest of us to enjoy.