The next-generation BMW M3 saloon and its M4 coupé sibling have been revealed in a series of images posted online ahead of their official debut tonight.

UPDATE: the new BMW M3 and M4 have been officially revealed - read the full story

Originally posted on Reddit, the high-quality images confirm that Munich's mechanically identical performance duo have a similar vertically oriented front grille to the newly revealed second-generation 4 Series, rather than a variation of the 3 Series' subtler front end.

Elsewhere, significantly widened wheel arches set the M3 and M4 apart from their standard counterparts, while bespoke rear-end designs incorporate a prominent downforce-enhancing diffuser, a subtle lip spoiler and a quad-exit sports exhaust. The pair also receive unique wheel designs, a contrasting roof and new bonnets with added creases for a more aggressive look.

The hotly anticipated performance saloons will use an extensively updated version of BMW’s twin-scroll turbocharged 3.0-litre straight-six engine, producing 473bhp and 443lb ft in entry-level form. As with the X3 M and X4 M performance SUVs, a top-rung Competition variant (which will likely be the only available option in the UK) will produce in excess of 500bhp.

For the first time on an M3, four-wheel drive will become an option soon after the new cars' launch but all forms of electrification are believed to have been vetoed. However, persistent reports suggest that they could be the final M models to be launched without some form of electrification; something made necessary by the increasing priority of meeting fleet-average CO2 targets.

There are no confirmed details about the pair's performance, but the lighter, more powerful cars will eclipse the current M3 CS’s 0-62mph time of 3.9sec. They will be sold with a choice of a six-speed manual gearbox or an optional eight-speed automatic, but the auto will enable better performance figures thanks to a built-in electronic launch control system.