WATCH: Range Rover Sport climbs stairway to heaven

Land Rover has released a new video of its facelifted Range Rover Sport tackling one of China's most challenging roads that culminates with the plug-in hybrid version of its SUV climbing 999 steps at an angle of 45-degree to its Heaven's Gate summit.

The stunt, which features the Range Rover Sport P400e, was driven by Jaguar Formula E racer Ho-Pin Tung.

In what's claimed to be the "hardest Range Rover Sport challenge" ever filmed, Land Rover engineers were keen to prove the plug-in version of the large, luxurious full-size Range Rover is equally capable off-road as its conventional diesel and petrol-powered siblings.

The Range Rover P400e was completely standard for the stunt, except for a set of off-road tyres for added traction on the slippery stone steps.

That means racer Tung had to rely on the plug-in hybrid's 221kW 2.0-litre turbocharged petrol engine boosted by a 85kW AC electric motor fed by a 13.1kWh lithium-ion battery.

Combined, the petrol-electric powertrain produces a formidable 297kW/640Nm -- enough for a swift 6.8-second sprint to 100km/h and a top speed (perhaps not up the steps) of 220km/h.

The only disadvantage of the new hybrid powertrain, which is claimed to help the big SUV average just 2.8L/100km is weight -- since the Sport P400e tips the scales at a hefty 2509kg.

Featuring a 50km pure-electric range, the downside of the plug-in powertrain is it takes two hours and 45 minutes for a full charge using a 32-amp charger (if you can find one Down Under), or 7.5 hours from a conventional power socket.

Claimed to be the first vehicle to ever attempt and climb the steps successfully, the Range Rover Sport P400e is set to land in Australia in June.