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The 2014 Range Rover Sport was unveiled during the 2013 New York International Auto Show. (John Minchillo/AP Photo)
The 2014 Range Rover Sport was unveiled during the 2013 New York International Auto Show. (John Minchillo/AP Photo)

The Green Highway

Aluminum means lighter cars, better fuel economy Add to ...

The New York Auto Show is not a “green” show; it is a luxury show.

Taking place in close proximity to Wall Street, auto makers rolled out their most expensive and extravagant offerings to tempt the money-is-no-object crowd. Yet, within the opulent wares, I could find promising “green” tendencies.

The key to improving vehicle fuel economy is weight reduction and the easiest way to do that is to make it smaller. A smaller vehicle requires less power; less power means smaller engines, which make the vehicle lighter still. Unfortunately, that’s not what many people want to buy and that’s not what luxury brands like Jaguar and Land Rover want to sell.

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It is remarkable that in grid-locked Manhattan, Land Rover has sold more of its top-of-the-line Range Rover Sport models than in any other city on Earth. These massive, luxurious machines, which are capable of running up the sides of mountains or plowing through raging rivers, can be seen all over town with their 510-horsepower V-8s idling in traffic jams behind buses and garbage trucks.

But the point I want to make is that the new Range Rover Sport is an astonishing 480 kilograms lighter than the outgoing model while being slightly larger in size. The reason is aluminum. Until now, the Sport had been based on the Land Rover LR3/LR4, with its heavy, steel ladder frame. Now the new Sport has switched over to the all-aluminum unitized body construction of the Range Rover flagship.

Tata Motors, owner of Jaguar Land Rover, has announced that all future Jaguars and Land Rovers will be aluminum-built. It can be a difficult material to form and weld, but Jaguar has developed the skills and machinery to do so. Now it’s confident enough to build Land Rovers and Range Rovers from aluminum, too.

Taking out so much mass makes the vehicles accelerate and handle like smaller, sportier rides. Of course, the Range Rover Sport could be lighter still, but that would cut down on the sumptuous interior, the hidden third-row seat, the 1,700-watt, 23-speaker audio system and loads of smart technologies like lane-departure warning, adaptive cruise control, blind-spot monitoring, forward-collision sensing, cross-car traffic detection and parallel-parking assist. The eight-speed automatic transmission, independent suspension, massive four-wheel disc brakes and electric-assisted rack-and-pinion steering also increase efficiency and driving dynamics.

This is an expensive luxury vehicle into which the extra cost of a high-strength aluminum body structure can be absorbed. Using a combination of pressed panels, plus cast, extruded and rolled aluminum alloy parts, has resulted in a platform weight-loss reduction of 39 per cent compared to the previous model.

The body accounts for about one-third of the weight of a vehicle. A lighter body can ride on a lighter suspension. Engineers say that, for every 10 kilograms saved by reducing the weight of the body, another 10 kilograms can be saved by downsizing other parts of the car. Jaguar Land Rover has moved into aluminum construction in a bigger way than any other mass-market manufacturer and has overcome some serious issues in the process.

That has enabled the aluminum Jags, Land Rovers and Range Rovers to all be unibody, short for unitized body, which is the design used for steel automobiles. In a unibody, the vehicle’s body panels are joined together to form a strong shell structure and this is not an easy trick in aluminum. The other approach is to employ a space-frame design, which is essentially an aluminum alloy frame structure covered with a thin aluminum skin. That only works well for expensive, low-volume cars like the mighty Audi R8.

JLR’s expertise in aluminum design, engineering and construction will give the company an even more significant advantage in keeping the performance in performance cars when government-imposed fuel economy standards really start to kick in. Whether this will ever be affordable in entry-levels cars is anyone’s guess.

I went looking for “green” at the New York Auto Show and found luxury instead. But aluminum luxury at least has some “green” potential.

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