Spy photos have shown the BMW i7 electric saloon undergoing extensive testing. The camouflage and cladding have hidden a model that’s expected to resemble its petrol-powered sibling, though surprises aren’t expected. However, one area BMW could excite is with the i7’s output. The company has yet to make anything official – and likely won’t until the reveal – though a new Autobild report says the saloon could offer 650 bhp (484 kilowatts).

The 650-bhp figure has been tossed around before, the suggested output for the top-tier offering, though there’s been no confirmation from BMW. The Autobild report is just the latest to reiterate a rumour that continues to circulate unabated. The report also notes that the German automaker will offer a 120-kilowatt-hour battery that’ll give the saloon a range of 700 kilometres (434 miles). Also in the report is the mention of a less-powerful variant with a smaller 80 kWh battery.

Gallery: BMW i7 Spy Photos

The smaller battery will likely power the rumoured 536-bhp (400 kW) model. However, previous reports noted that this model would receive the same 100-kWh battery as the 650-bhp one. Autobild’s report could be the first indication of yet another variant that might serve as the entry-level model of the trio. The 650-bhp i7 would likely become the most powerful 7 Series variant, bypassing the M760i’s 6.6-litre V12’s 601 bhp (448 kW).

While spy photos show that the car has undergone significant development, we’ll be waiting for anything official from BMW about it. The automaker isn’t expected to reveal the new vehicle until sometime next year, as it’ll arrive for the 2023 model year. It’ll compete against the Mercedes EQS, which rumours suggest could receive a high-performance AMG version, too, which would help justify a 650-bhp i7 in BMW’s stable. The BMW is also likely to receive a bevy of safety features and semi-self-driving technologies.