The Range Rover SUV is crucial for Land Rover as it's not only the model that best defines the brand, but it’s also the one that most of Land Rover’s other vehicles are based on. Models like the Range Rover Sport, LR4 (Discovery) and LR2 (Freelander) all share their basic design and technology with the Range Rover, so as you can expect engineers have a lot of pressure resting on their shoulders developing the next-gen model.

Expected to go on sale later this year as a 2013 model, the new Range Rover is thought to feature a lightweight, rivet-bonded aluminum chassis based on a modified version of the platform underpinning the Jaguar XJ. By using the lightweight material, engineers could shed up to 40 percent from the weight of the current model’s unpainted body shell, equating to a saving of roughly 660 to 880 pounds. Advanced composites are also expected to be used for certain elements, such as the body panels and rear tailgate, along with some high strength steels.

This would give the vehicle a final curb weight roughly equal to a fully-loaded luxury sedan, improving both performance and fuel economy--the latter of which is expected to be as high as 33.3 mpg combined for some models. This same platform will also spawn a new-generation Range Rover Sport, which is expected to replace the LR4 model in Land Rover’s lineup and be available with seven seats for the first time.

These latest spy shots reveal several telling details about the styling of the new Range Rover, as well as its interior. Code-named L405, the new off-roader is almost ready for its debut, which is scheduled to take place at September’s 2012 Paris Auto Show though an online reveal is expected even earlier.

The vehicle looks to be slightly longer than the current model, with its roofline considerably lower as well. This should result in lower drag and a smaller overall look. The new headlights will also feature a cluster of LED daytime running lights as revealed in some of the spy shots.

2013 Land Rover Range Rover spy shots

2013 Land Rover Range Rover spy shots

Inside, the vehicle will be decisively more upmarket to allow it to better compete with luxury SUVs being developed by Bentley and Maserati, with plenty of modern touches here including a digital instrument display, large LCD screen in the center console and plenty of controls to adjust everything from the audio and climate settings to the advanced off-road gear.

Powertrain options will largely carry over from the current model and include naturally-aspirated and supercharged 5.0-liter V-8s, as well as a new turbodiesel and gasoline V-6 units for overseas markets. Output will range from about 260 to 510 horsepower. Also due out a couple of years after the initial launch is a hybrid version offering a combined fuel economy as high as 33 mpg.

While you await the reveal of the new 2013 Land Rover Range Rover, click here to watch a spy video of a prototype.