In recent years we've finally seen a reversal of the trend towards heavier cars, but Jaguar will take that a step further when it launches the 2016 XE sedan.

Long-awaited replacement for the unloved X-Type, the XE's body structure is 75 percent aluminum, the highest of any in its class.

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That, says Jaguar, will make its body the lightest in the class, among rivals such as the BMW 3-Series, Mercedes-Benz C-Class and Lexus IS.

It remains to be seen how light the car is as a whole, since a light body structure can still be offset by the weight of engines, interior trim and other features.

In the 2015 Ford F-150 truck, aluminum has allowed Ford to shed hundreds of pounds from the weight of its predecessor. Jaguar itself already uses aluminum to great effect in the F-Type sports car and XJ sedan--the latter weighs no more than the smaller, steel-bodied Jaguar XF.

On smaller vehicles like the XE there's some degree of diminishing returns, but the light structure should give the car a head-start in efficiency against its rivals. So much so, that Jaguar is boasting combined economy of 62 mpg on the European cycle for the thriftiest diesel option.

Naturally, that estimate is far greater than whatever the car would achieve in EPA testing thanks to Europe's optimistic test cycle, but to put some perspective on that figure, it's 6 mpg higher than the most frugal 3-Series on sale in Europe, and only 2.5 mpg off the best C-Class.

The real benefit of such figures in Europe is a CO2 figure below 100 grams per kilometer--the point at which a significant tax break occurs in several European markets.

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As well as contributing to fuel efficiency, Jaguar explains several other benefits of the aluminum structure.

Low weight doesn't come at the expense of stiffness and crash absorption, as the bonded and riveted structure is incredibly strong with high levels of torsional stiffness--resistance to twisting forces.

The stiff structure and lack of weight should play dividends for handling and ride quality too--stiffness ensures engineers can better calibrate the spring and damper rates, while light weight means a softer setup can be used without sacrificing handling.

It's relatively environmentally-friendly too. The aluminum, called RC 5754, features a high level of recycled materials. Jaguar Land Rover intends to use 75 percent recycled materials in its vehicles by 2020.

The 2017 Jaguar XE will make its full debut in London on September 8.


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