New M5 is gonna have a 5 litre V-10  

At the new M5’s heart is a purpose-built 5.0-liter V10 delivering 507 hp. With individual throttle butterflies, BMW’s bi-Vanos variable valve timing, dual-flow stainless steel exhaust system and a stratospheric 8250-rpm redline, the BMW delivers its 507 hp at 7750 rpm and 383 lb-ft 6100 rpm. This is up 107 hp and 15 lb-ft on the outgoing model’s 4.9-liter V8 engine, making the new M5 is the most powerful road-going BMW ever.

The engine is mated to a third-generation version of BMW’s sequential manual gearbox (SMG), now boasting seven forward ratios and new electronics to speed shift times 20 percent. With 11 different shift programs, six in manual mode and five in automatic, the driver can tailor the gearbox’s action to suit the conditions. There’s even a launch control function.

Another new feature is the M5’s power button. At start up, the driver is given access to 400 hp in a default program, dubbed P400. Depressing the button unleashes P500 and the engine’s full 507 hp wallop along with a more responsive throttle. In P500 BMW says the new car will hit 60 mph in 4.7 seconds and its 155 mph top speed in 14.9 sec. With its speed-limiting chip removed, BMW says its new sedan will reach 205 mph, although company policy prohibits official modification, even at the dealer level.

Underpinning the new M5 is a modified version of the 5-series’ MacPherson strut (front) and multi-link (rear) suspension. While the geometry and pick-up points are the same, the ride height has been reduced and more negative camber added to handle cornering forces BMW claims can top 1.3 g.

The new car also adopts electronic damping control (EDC), providing the driver with three stiffness levels: comfort, normal and sport. The EDC is linked to the M5’s power steering system, which provides the driver two assistance levels.

There’s also two-stage dynamic stability control (DSC); the first stage with grip levels corresponding to a standard 5-series, the second stage, dubbed M Dynamic, allowing what BMW describes as “greater levels of slip.” Helping to rein the new M5 in are impressive looking 14.75-inch (front) and 14.5-inch (rear) ventilated and cross-drilled steel discs with twin-piston aluminum calipers. BMW says 62 to 0 mph takes less than 118 ft and 124 to 0 mph less than 460 ft.

BMW claims the new M5 can lap the Nürburgring, where much of its development was done, in 8 minutes, 25 seconds less than the outgoing M5.

Oh I don't know Richie, personally I still rather like the Gp 4 Lancia Stratos, and its about the same age as me