As cars get heavier, even small speed differences matter in a crash
Enlarge / A Volvo XC90 SUV following a crash check in Sweden.

Jonathan Gitlin

At the tip of January, security researchers on the AAA Foundation for Traffic Safety and the Insurance Institute for Highway Safety printed a research exhibiting that small will increase in speed have massive penalties throughout a crash. After crashing three similar cars at growing speed, the research confirmed that a automotive that aces the check throughout the board at 40mph (64km/h), with simply a 15 p.c likelihood of great harm might get a failing grade general, with a 59 p.c likelihood of great harm at 50mph (80km/h). At 56mph (90km/h), the outcome was even worse; the fiftieth percentile male crash check dummy solely had a 21 p.c likelihood of escaping critical harm or worse.

No doubt, the truth that autos are designed to go a 45mph (73km/h) crash check and never one thing at freeway speed has one thing to do with the outcomes of the research. But it is also a reminder of fundamental physics: a automobile’s kinetic vitality is the same as half its mass multiplied by the sq. of its speed. So, the common US light-duty automobile—which weighs about 4,000lbs (1,814kg)—has 11.2kJ when it is touring at 25mph (40km/h) however 22kJ at 35mph (56km/h), a reality that folks can use subsequent time somebody complains that metropolis speed limits are too sluggish.

But speed is, actually, solely a part of the equation. Local authorities can set limits on how briskly we are able to drive, however nobody’s going to cease you shopping for a 5,000lb (2,268kg) automotive as an alternative of a 4,000lb one. And massive cars are enticing to most people. Ironically, a lot of this development is fueled by the truth that security sells, and the most important, heaviest cars are the most secure—for his or her occupants, at the least. Pedestrians or individuals in older or smaller cars? Not a lot.

All issues being equal, a larger and heavier automotive will deal with worse. You can compensate for that in some methods, as +5,000lb cars just like the Porsche Taycan Turbo, Audi RS7, and Aston Martin DBX all present. Fast-reacting adaptive suspension and an extra of energy is a good method to beat inertia when the time comes to start out shifting or change course. All that stuff exists, but it surely all comes with its personal baggage. Adaptive suspension is dear and provides loads of weight simply by itself. Electric motors are nice as a result of they’re so torquey, however now it’s worthwhile to carry a whole bunch of kilos of lithium-ion cells, which once more, is not low cost. And glacier-melting twin-turbo V8s are more and more untenable due to the glacier-melting bit.

Powerful engines and sensible dampers are all properly and good for beginning and swerving. But you may’t actually disguise a automotive’s mass when it is time to decelerate or cease. Heavy cars want massive brakes and longer braking distances and tires that may address the entire above, rain or shine.

Less could be extra

At the opposite finish of the spectrum is a light-weight utopia, one envisioned by designers like Gordon Murray. He places his cash the place his mouth is, too; none of his private cars—together with a kind of Suzuki Jimnys that everybody loves a lot—weighs greater than 2,500lbs (1,134kg), if reminiscence serves.

Lighter cars have a payoff for lovers in addition to the security aware. The much less mass a automotive has to maneuver, the higher it handles. And it will not want practically as a lot energy to get shifting in the primary place. Lighter, much less highly effective cars have way more accessible limits, which suggests you may have enjoyable driving them at socially accountable velocities. In reality, I’m nonetheless wistful over my previous 1996 Ford Ka. With simply 59hp (44kW) and a couple of,002lbs (908kg), it stays etched in my reminiscence as one of the satisfying cars to drive daily.

The true godfather of lightweighting was Colin Chapman, founding father of Lotus, who might have been extra obsessive about weight than Murray. Chapman described his philosophy as “simplify, then add lightness,” and that has been a hallmark of Lotus by good occasions and dangerous. Some of the dangerous included racing cars that have been usually too fragile for their very own good, with tragic penalties. But the great have been highway cars that outhandle any of their rivals and sometimes at a eager worth.

Since 1996, Lotus has existed on the success of the Elise and different light-weight sports activities cars derived from its still-innovative extruded and bonded aluminum chassis. I’ve nonetheless by no means pushed one, and I stay unhappy about that. Perhaps if the pandemic ever ends, the good individuals on the Lane Motor Museum in Nashville may let me come and do a function on their instance.

I’ve pushed a Lotus Evora in Monterey in 2019. Yes, a automotive weighing 3,100lbs is what passes for light-weight today, which does sound loopy while you say it out loud. It was fantastic to drive however not pretty much as good to stay with as a Porsche 911. Not that you’ll purchase one for for much longer: Lotus is shutting down the manufacturing traces at its manufacturing facility in Hethel, England, in order to retool for an all-new automotive, recognized solely as Type 131 for now.

The yellow car is the Lotus Evija, a very expensive, very powerful electric supercar that will be built in tiny numbers. But the Type 131 should be much more attainable.
Enlarge / The yellow automotive is the Lotus Evija, a very costly, very highly effective electrical supercar that can be constructed in tiny numbers. But the Type 131 needs to be way more attainable.

Lotus Cars

I’m very excited to see how the Type 131 develops, in addition to how Lotus adapts to life beneath the possession of Geely. How it really works with Volvo’s elements bin in specific intrigues me—Volvo additionally being owned by the Chinese firm. And I’ve simply realized meaning future Lotuses will run Android automotive. A Lotus-badged crossover of some type appears inevitable, which is able to set off all method of complaining. But if Porsche could make the Macan GTS nice to drive, I’ve no worries that Lotus will work its magic.

Still, Murray and Lotus are outliers, and the philosophy of lightweighting has far to go earlier than it is a mainstream perception in the auto trade. But a man can dream, cannot he?