Thought BMW wouldn’t be able to one-up the already massive X7? Well, think again, as Munich is already considering a new flagship X8 to slot above the yet-to-be-launched model, according to Autocar.

Set to be launched in 2020, the new car is poised to take on other luxury SUVs such as the Range Rover and the upcoming Audi Q8, as well as base versions of the Bentley Bentayga, Lamborghini Urus and even its stablemate the Rolls-Royce Cullinan. Head of development Klaus Fröhlich stopped short of confirming the model, but he did say there was room beyond even the X7.

“The sector is growing fast, so there will be opportunity,” said Fröhlich. “It is early to talk about X8, but one of the first decisions I made when I worked on product strategy was to take the X5 and make the X6. Everyone said it was not necessary, but it worked.

“Now we have the X2, X4 and X6. They are emotional and sporty derivatives that work for us. There is room for X8 – especially in markets like China – but there are no decisions yet. Each car must have a distinct character, and these are the sort of areas that take time to evaluate.”

There’s still a debate over whether the X8 should be a “coupé” version of the X7 (as is traditional of even-numbered X models versus their odd-numbered counterparts), or a long-wheelbase variant. Whatever form it will take, it will most likely have a four or five seats rather than the seven on the X7, with greater emphasis on rear-seat luxury and comfort – with materials and finishes to match – instead of outright practicality.

Although building a larger model is reportedly the more favourable option, Autocar suggests that this would add complexity to the project. Such a vehicle may need to be built on a mix of BMW’s modular Cluster Architecture (CLAR) and Rolls-Royce’s new Architecture of Luxury aluminium spaceframe – which will underpin the Cullinan – in order to achieve rigidity without adding too much weight or cost.

The company is also deciding on how raked the roofline should be, given that most X8s would be chauffeur-driven. Also up for consideration is how much visual differentiation the X8 should receive vis-à-vis the X7, and while a sweeping roofline would set it apart from the bluff X7, it would be difficult to achieve that while retaining a cohesive design and without bringing the roof height down before the boot area.

The X6 “coupé” set the template for even-numbered X models

Looking at the dimensions of the Concept X7 iPerformance, Autocar says there is definitely room for a longer model. With a length of 5,020 mm and a wheelbase of 3,010 mm, the X7 is shorter than the Mercedes-Benz GLS, which has a length of 5,131 mm and a wheelbase of 3,076 mm. Meanwhile, the Range Rover measures 5,199 mm long and has a 3,122 mm wheelbase in long-wheelbase form – 200 mm longer than the standard version.

If it does come into fruition, the X8 will likely be eventually offered with the same engine options as the X7, but the greater focus on Chinese, Russian and Middle Eastern markets could see initial offerings be limited to more powerful petrol or plug-in hybrid powertrains, such as the M760Li‘s 6.6 litre twin-turbo V12 making 610 hp at 5,500 rpm and 800 Nm from 1,550 rpm.

Meanwhile, the PHEV model should get the same set-up as on the 740Le, which on the sedan incorporates a 258 hp/400 Nm 2.0 litre turbo petrol four-pot, an 113 hp/250 Nm electric motor and an eight-speed automatic transmission to produce a total system output of 326 hp and 500 Nm of torque. However, the battery will likely have a larger capacity to provide an all-electric range of 100 km.