Just 12 months after confirming that it was getting ready to build its first luxury off-roader and a totally new ground-up platform, Project Cullinan, as Rolls-Royce has christened it, has already moved onto the on-road testing phase. Now, the BMW-owned firm has announced the all-aluminum space-frame of all future models will begin on-road testing too.

And once the testing, which will see development mules take to public roads all around the world, is complete, expect not just the new Rolls-Royce SUV of Project Cullinan but also an entirely new flagship Phantom to follow closely in its wake.

“Now it is time to take the next step in the luxury journey. This is why I am announcing today that on-road testing of our all-new proprietary architecture is beginning. This new architecture of pure luxury represents considerable investment in the future of our great brand,” said company CEO, Torsten Müller-Ötvös.

That is an understatement. The current Rolls-Royce Phantom platform, which has been in use since 2003, is already an engineering marvel; the brand new architecture is set to become the biggest and most complex aluminum space-frame to underpin any car currently in production anywhere in the world. The huge advantage of aluminum is that it is extremely strong yet extremely lightweight so that a Rolls-Royce can be hugely accommodating and massively imposing on the road, yet still be capable of accelerating and stopping without the use of a jet engine for propulsion or parachute for braking.

The Project Cullinan mule that has been appearing on streets since the middle of last year

However, aluminum has a habit of misbehaving – expanding and warping – so the fact that each frame is hand-built (artisans weld each joint) makes everything even more remarkable, still.

The new platform will be even more complex in order to support new drivetrains and next-generation safety and connectivity technology from sensors to infotainment.

When Rolls-Royce announced it was building an SUV, purists were dismayed, but as the company’s design chief, Giles Taylor, recently told Relaxnews that the benefits offered by SUVs, such as an elevated driving and passenger position, plus the fact that it can handle terrain such as sand are perfectly in keeping with what the typical Rolls-Royce client needs. It’s why they have usually had a Range Rover or Mercedes G Wagon for weekend trips to the desert or mountains.

But what Rolls-Royce is aiming to deliver is a vehicle that can go further but without compromising on the brand’s legendary “magic-carpet” ride quality that irons out even the biggest bumps in the road.

“Since 2003 and the commissioning of the new Home of Rolls-Royce at Goodwood, Rolls-Royce Motor Cars has reset the benchmark for luxury motoring,” said Müller-Ötvös.