Land Rover has announced a new mild hybrid version of its high-end Range Rover Sport model.

Initially available solely on the HST special edition model and priced from £81,250, the newcomer uses a 3-litre straight-six turbocharged petrol engine and a mild hybrid system, which uses an electric motor to harvest energy normally lost under braking. This power is stored in a 48V battery and can then be used to improve the engine’s efficiency when it is under load, such as when pulling away from traffic lights.

But electricity isn’t just used to reduce the amount of fuel used - it’s also there to make the car faster and more responsive. Land Rover has fitted an ‘electric supercharger’ system, using the electrical power to spool up the turbocharger more quickly and reducing the ‘lag’ usually associated with turbocharged engines.

In total, the system produces 394 bhp, allowing the big 4x4 to sprint from 0-60 mph in less than six seconds and hit a top speed of 140 mph. And because of the mild hybrid technology, the car returns 30.5 mpg and emits 213 grams of carbon dioxide per kilometre. It doesn’t sound like much of an improvement, but bear in mind that this engine’s predecessor - a supercharged V6 from the Jaguar F-Type - was only capable of 26.9 mpg and 243 g/km on the now-defunct and less stringent NEDC economy test. And that’s despite the V6 having less power.

2019 Range Rover Sport HST

Nick Rogers, executive director of product engineering at Jaguar Land Rover, said the new engine would also be more refined than the old V6 thanks to its in-line layout.

“In-line six-cylinder engines are inherently better balanced than V6 designs and our all-new Ingenium unit builds on that promise to optimise efficiency in all operating conditions. Advanced features, including an electric supercharger, ensure distinctive Range Rover Sport performance and responses, while the intelligent MHEV system harvests energy to improve fuel economy and reduce emissions.”

2019 Range Rover Sport HST

The new engine is not the first mild-hybrid unit to find a home under the bonnet of a Land Rover, after the new Range Rover Evoque was revealed a few months ago with mild hybrid power. The new 3-litre engine will be built alongside those powertrains at Jaguar Land Rover’s engine plant in Wolverhampton.

2019 Range Rover Sport HST

Although Land Rover has said the new engine will only be used “initially” in the special-edition Range Rover Sport HST,  the company’s use of the word “initially” suggests it will feature in other models eventually.

For now, though, that means the starting price is a little over £81,000, but you get a range of internal and external updates for your Range Rover Sport, including carbon-fibre trim on the bonnet, grille and side vents. You also benefit from 16-way electrically adjustable Dynamic seats, plus red brake callipers and chrome gear shift paddles. There’s a choice of five exterior colours, too, including Santorini Black, Fuji White, Indus Silver, Firenze Red and Carpathian Grey.

Gallery: 2019 Range Rover Sport HST