Rolls-Royce's Project Cullinan, a diamond in the rough?

Rolls-Royce has published the first images of its test mules and offered the first progress report into the development of its first ever SUV.

Project Cullinan, as it's being referred to within the company, shares its name, quite appropriately, with the largest gem-quality rough diamond ever unearthed and is now part of the Crown Jewels of the United Kingdom.

The British royal family are traditionally both Rolls-Royce and Range Rover customers and the question hanging over this project is whether or not the resulting vehicle will entice existing clients like European nobility?

To this extent, Rolls-Royce is refusing to refer to the car as a Sports Utility Vehicle. In its official letter to shareholders announcing the project's inception in February, Rolls-Royce described it solely as a high-sided vehicle.

The first images of the test mule don't give much away other than some idea of the car's size. It will be almost as big as the company's flagship Phantom limousine but will be able to offer the famous magic carpet levels of ride comfort both on- and off-road.

The company has confirmed that the car in the images is testing a new all-wheel drive suspension system and that it will have to be able to conquer 'Belgian Pavé, cobblestones, corrugated concrete, noise development and measurement surfaces, resonance road, and acceleration bumps,' in order to make the grade.

The high rear spoiler also indicates that the car will stand much taller and is possibly there to increase the amount of body roll to replicate the behavior of a real off-roader.

Rolls-Royce is racing into the luxury SUV space because the competition is increasing.

Bentley is to launch its first premium off-roader, the Bentayga, in 2016 and aware of the threat, Land Rover used this year's New York Auto Show to unveil the SVAutobiography, its most powerful, luxurious, expensive and exclusive Range Rover in history.