Hardcore Land Rover Defender Octa global debut on July 3

As JLR prepares for the debut of its first electric Range Rover, it is also gearing up to reveal the most extreme V8-powered 4x4 it has yet produced. The Defender Octa will be revealed on July 3 as a highly exclusive and extremely capable super-off-roader, which is set to use the twin-turbocharged, mild-hybrid 4.4-litre V8 from BMW, as deployed in the X5 M and X6 M SUVs.

1. Octa has done 13,960 more tests than standard Defender, claims JLR
2. Octa name said to come from the octahedron shape of a diamond
3. Range Rover Sport SV already uses the BMW-sourced V8 engine

Just 1,070 examples of this hardcore special edition will come to the UK in its first year of production, featuring "tough luxury material choices, striking exterior and interior design enhancements, and the options available to make every adventure epic", according to JLR.

The latest round of preview images show the Octa being subjected to "the most extreme" test programme of any Defender variant yet, with engineers conducting a claimed 13,960 additional tests on top of the standard Defender test programme. So far, it has conducted countless laps of the Nordschleife, tackled Michelin's wet-weather handling circuit in France, had its traction control put to the test on Swedish ice and taken on some of the world's most challenging off-road trails in Dubai and Utah.

JLR says it has also “conquered every extreme trail" at the company's 4x4 test track in Eastnor, Herefordshire. Interested customers are being invited to sign up for one of seven ‘Defender Elements’ preview events being hosted worldwide in the coming weeks, but the brand has given no indication of pricing yet. It's safe to assume the Octa's limited, extreme billing will make it the most expensive Defender.

Previously thought to carry the long-dormant SVX branding, the radical new off-roader has been spotted testing several times, but only now – a few months before its debut – has the firm given the first official details of the new model.

It will be the first car to wear the new Octa badge, which JLR says will be used for all future range-topping Defender models. The name is said to come from the octahedron shape of a diamond, the hardest naturally occurring mineral on Earth – a reflection, no doubt, of both the car’s durability and price.

Technical details remain largely under wraps, but JLR has confirmed the new variant will use a twin-turbocharged V8 rather than the supercharged 'AJ' unit in the existing eight-cylinder Defender models. The predicted 4.4-litre BMW-sourced unit is already used in various Range Rover models, including the Sport SV. In that car, it puts out 635hp and 800Nm, and propels the 2.5-tonne SUV to 100kph in just 3.8sec.

Using the BMW engine would suggest that the long-running 'AJ' V8 is not long for this world. Our sister publication Autocar UK previously reported that AJ production ended last year, and that JLR retained a stockpile of supercharged 5.0-litre units, of indeterminate quantity.

JLR has also revealed that the Octa will use the same ‘6D Dynamic’ suspension system as the Range Rover Sport SV. This system hydraulically links the dampers front to rear as well as side to side, providing active control over the car’s pitch and roll without a physical anti-roll bar. That should help to provide the level of wheel articulation required by a hardcore off-roader like the Octa, without compromising on-road drivability or comfort.

Images published by the firm reveal that the Octa also receives a bespoke set of Brembo brakes, suggesting on-track performance is a priority. These are marked with the special Octa diamond logo, which also features on the steering wheel and side-pannier mounts.

JLR in India

Although there's no word on if and when the Defender Octa will arrive in India, Land Rover currently has the off-roader on sale here in 90, 110 and 130 guises, which prices ranging from Rs 97 lakh to 2.3 crore, ex-showroom, India.