January 3, 2011

Editorial: I'm ready for my car of the future, and it doesn't even have to fly

Share

Face it: you're never going to have a flying car. Even if the Moller Skycar were cheap and common enough for everyone to be able to afford, the first time some bleary-eyed morning commuter spilled coffee on their lap and made a spiraling dive into a kindergarten, they'd all be grounded. Permanently. We might get there some day, but the next few generations of tomorrow's cars are going to stay firmly planted on the ground. I'm okay with that. In fact, I like that. After all, it's pretty fun to drive on the ground -- or a lake, if the ice is thick enough.

If we're stuck with such pedestrian things as wheels and tires and fenders, what's the next-generation of cars going to look like? Are hybrids really a hot thing or are they the automotive equivalent of a transition medium? Will tomorrow's cars continue today's horsepower wars or are a nation's dyno graphs on the verge of a beige econo-precipice the likes of which we haven't seen since the '70s fuel crisis? Damned if I know, but I do at least have an idea of what I believe the next generation of cars should be, something that could be produced in five years or less and would totally rock my world. Maybe it will rock yours, too.

In the world of automotive design there are few bigger names than Anthony Colin Bruce Chapman, nor are there many visionaries whose principles have been more ignored over the years. Chapman's most famous quote is: "To add speed, add lightness," but I think this one's even better:
Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere.
This was the key to Lotus cars on the track and off, a concept that major manufacturers have all moved away from, their autos burdened with ever bigger motors, bulkier frames, and more airbags. Even Lotus is following the trend.

A key concept of my ideal (but theoretical) car of tomorrow is to reverse that trend, to make them truly light again. Let's say 1,500lbs for a roadster, 2,000lbs for a sedan, and exterior dimensions smaller than a Ford Focus or a Mazda 3. Today's cars that have grown and swelled to obscene proportions, burdened by once simple solutions to simple problems that bumped up against other solutions to other problems and in turn created new problems. Heavier cars need bigger motors to keep them going as fast, which means bigger wheels and tires, bigger brakes, bigger fuel tanks... more weight to haul around. So the cycle continues, spiraling out of control.

At some point things got ridiculous, and indeed it's hard to not look at some of the attempts to make a giant, heavy, modern car more efficient as anything but ridiculous -- like clipping the toenails on a grizzly bear. A 1982 Toyota Camry weighed 2,300lbs. A 2011 Camry Hybrid? 3,680. That first Camry managed 44mpg, 10 morethan the modern hybrid. It's time our cars went on a diet, starting on the inside.

Each time I go to CES I see more and more impressiveinfotainment and telematics systems and as ever I can't wait to see what's next. But, I also can't help thinking the companies making these systems are wasting their time.

It's time for the car's entertainment and navigation systems to be deleted. Smartphones do all that and more, with a cleaner, more user-friendly interface. Delete the stereo, delete the navigation system, delete the in-car cellular antenna, get rid of all that. Replace it with a simple smartphone dock and an amplifier. It's more weight saved, and less space taken up by a tangle of wires under the dash.

In fact, ditch the whole dash. Put all the gauges on the steering wheel like an F1 car. Build the heating and cooling vents into the frame of the car and the seats. Simplify things, streamline them, a little like BMW'sVision EfficientDynamics above -- but maybe toning down the swoop a bit. Less dash means fewer things to hit in a crash, which could mean a reduced need for airbags and safer impacts overall.

Yes, my ideal car of sometime after tomorrow is battery powered. Not a hybrid, no plant mash and microbes brewing away in a fuel cell, not a single tank storing hydrogen or anything of the sort. I want a pure EV powered only by batteries, and it's not because I'm an enviro-minded hippie who's only worried about emissions, man.

It's because, simply, EV is cleanest design. An internal combustion engine tries to capture the explosive force provided by a burning fuel and turn that into linear acceleration. After hundreds of years of refinements even the best engines do a damned poor job of it. A hybrid improves that efficiency, but shoots itself in the foot with yet another motor (or two) and a load of batteries and wires and processors and a gearbox capable of giving a mechanical engineer nightmares. All that means more weight, and remember: weight is bad.

It's much the same story with a fuel cell car, though now you're trying to squeeze electrons out of hydrogen or the like, then sticking that in a (much smaller) battery, then turning around and pulling it back out to power an electric motor. This requires a big, rupture-proof tank situated somewhere inside the body and, perhaps more troublingly, a nation-wide hydrogen distribution system. I've yet to see a single hydrogen pump at a highway rest area. They all have electricity, though -- and Starbucks.

Sure, EVs right now mean short range, the little Leaf managing a little over 100 miles with a stiff tail wind, the Tesla Roadster 200-odd. But, remember: these are on the leading edge of the EV wave. In a few years battery life and design will be better, meaning lighter weight, longer range, and quicker recharging. And don't worry early adopters, because you'll probably be ready for a new ride by then anyway. These are, after all, cars.

Drivetrain

So it's an EV, then. That means batteries with wires, wires running to one or more electric motors. Current EV designs generally rely on a single large motor doing its thing in the traditional location under the hood. Mechanical power gets run through a transmission and differential. Differentials sit between wheels and allow them both to be spun by a single motor, each rotating at different rates so you can go around turns and things. Along the way all those gears suck down 10 or 15 percent of the power coming out of the motor. What do you get in return? Noise, some heat, and pools of slippery fluid that need to be drained and changed at regular intervals.


A better way? Ban the transmission, and the diffs too, and get rid of all that loss and rotational mass. Put a motor at every driven wheel, preferably one at each corner (mounted to the chassis, not the wheel itself). That's not to say you could simply connect the output shaft from the motor to the wheels, though. At highway speed an average tire turns over a couple-hundred times per minute, while an electric motor is perfectly happy to spin up over 10,000 RPM. Reduction gearing would still be required, a much more simple and efficient option than a full tranny and multiple diffs.

There are other advantages to putting a motor at each corner, a big one being brakes. A front-wheel drive hybrid can use its electric motor to brake and re-fill the battery, but the effect can't be too strong as you need to use standard, friction brakes on the two wheels chilling out back. An electric motor at each wheel means you can rely on regenerative braking to do most of the car's stopping, with only tiny friction brakes required to bring the car to a stop (regenerative braking loses efficiency at low speeds) -- and to keep it from rolling down the hill when parked.

This type of arrangement opens the door to what could be the most advanced torque distribution system known to man. Nissan's latestGT-R is capable of besting the lap times of cars that are more powerful and lighter thanks to its trick all-wheel drive system. But, it's a big, heavy thing: the engine at the front spins a shaft that turns the transmission and differentials at the back. A second driveshaft then runs from the rear of the car back up to the front to spin another differential hanging out between the steering wheels. Counting the transfer case that's three differentials, two driveshafts, and one transmission just to get power to all four wheels.

Four electric motors, a central computer having precise control over the RPM of each one, would make the GT-R's drivetrain arrangement look like a trebuchet sitting next to a railgun.

The elimination of the engine, fuel tank, driveshaft, exhaust, and all the other bits and bobs that go along with them frees up a huge amount of volume inside the frame of the car. Sure, you now need to replace that with the electric motors and the batteries to drive them, but those motors are much smaller and lighter (a Tesla Roadster's electric motor weighs about 70lbs), and the battery pack (or packs) can be shaped to occupy the floor of the car.

That would leave a flat, open space upon which to set the interior, and open the door to throwing the traditional two-seater and 2+2 layouts out the window. I've always been intrigued by the McLaren F1's arrangement with the driver in the middle and a passenger on either side. With no transmission/exhaust tunnel running down the middle of the car, why not a three-seat roadster or 3+3 sedan?

Charging: lose the wires


Wired chargers make a lot of sense for EVs and should continue going forward, especially CHAdeMO, which leaves all the heavy AC/DC conversion equipment outside of the vehicle (like a giant power brick on a slinky little laptop) and can charge an EV to 80 percent capacity in 30 minutes. That is, really, no time at all, and if we pessimistically say that we can get to 350 miles range in 5 years, thanks to a combination of better batteries and lighter overall weight, that would mean a 30 minute coffee break at a rest stop for roughly every four hours on the highway.

That's not so bad, is it?

In addition, EV makers need an inductive, wire-free charging standard. You'd never get the voltage achievable through a wired solution (at least not without making everyone within 100-feet glow in the dark), but even slower charging would make life more convenient. You could juice an entire parking lot without having to worry about vandalism; let people top of their batteries while hunting for bouillon cubes in the grocery store. Maybe in the future we can build highways that recharge cars on the go, extending their range.

Who's going to build it?

This is perhaps the toughest question. A car of this design, a completely unconventional frame with an odd interior layout and an even number of motors, wouldn't exactly fit into the tooling that major manufacturers have spent decades bolting to the floor. That's fine, let's give the little guys a chance.

In the early days of the auto, buying a car was a little more complex. You went to a chassis manufacturer and ordered some rolling stock, chose a motor to slot in, and then delivered the pile to a coachbuilder. They'd throw it all together and put a body of your choosing on it -- even crafting a custom shape on their rollers if you had the scratch.

Let's bring some of that componentization back. If at CES this year ASUS launches a laptop with a CPU, GPU, memory, storage, and display all made entirely by in-house, with no help from Intel or AMD or Samsung or anybody, you wouldn't expect it to out-perform the competition. Why should it be any different with cars?

General Motors or Toyota or Tesla aren't going to make the best electric motors in the world, and the best battery packs, and the best inverters, and engine control systems, and everything else required. Let a few companies focus on making the best motors. Let a few others focus on making the best batteries. Let you, the buyer, pick which ones you want, and let some smaller car manufacturers put it all together. Let's see what Caterham, Local Motors, Weismann, Ariel, and all the other mini marques can do.

Wrap-up

Am I dreaming here? Yeah, absolutely, but the technology is there. We could do this in five years, all we need to do is start with a clean slate. That's easy enough with a laptop or a smartphone, but in a car people are more conservative, in part because their lives are on the line. Education is needed to teach people that, when it comes to an accident, avoidance can be even more important than survivability in a crash. That small cars, with the right construction and features, aren't deathtraps. That giant wheels and lifted suspension don't give you more grip on a snowy day. That you could fit five sweaty kids in a small car and still have room for all their soccer equipment in the trunk. And, perhaps most importantly, that EVs don't have to be boring.

To enable a coachbuilder renaissance we'd need revision and simplification of crash testing regulations, global standardization of New Car Assessment Programs (NCAP), and easing of regulations surrounding the import and export of cars. In exchange we'd get hugely light, hugely efficient, and hugely fun to drive machines that could be even faster than today's portly 500+hp beasts.

And that's really all I want: a fast, fun, car that can finally shrug off 100 years of industry dead weight.

0 comments: