It's amazing what you can find out in the snowy woods of Sweden: our spy photographers have just bumped into the new F10-series BMW M5, the new high-performance super saloon coming in 2011.
The maximum 5-series is on winter test in Sweden, as engineers hone the new bi-turbo V8 that will replace the 5.0-litre V10 of today's E60 M5.A V8? Turbos? What the devil are BMW playing at?
Calm down, it's all to do with emissions. The old V10 sang like a canary when you revved it, but it also gobbled the world's resources with too much abandon. So BMW's fitting the (marginally) less thirsty, downsized 4.4-litre V8 we've already seen in the X5 M and X6 M.
It'll develop a heady 578bhp, but the real boon is in torque. The naturally aspirated V10 was charismatic but low on grunt, and the twin-turbo V8 delivers that in spades: around 530lb ft of the stuff, according to information seen by our European correspondent Georg Kacher.How quick will the new BMW M5 be?
When it's not on snow, you can bank on 0-62mph in 4.4sec – three tenths faster than the outgoing M5 – and a top speed nudging 188mph, when the electronic shackles are lifted.
So performance will be electric, but it's the way it combines fast with frugal that's the most impressive aspect of the next M5, say engineers. We hear it'll use 30% less fuel than before, thanks to the downsized engine, active aero, stop-start and a seven-speed twin-clutch transmission.
even be a flywheel power recovery system, although that has not yet been signed off, our sources say. But you can bank on around 24mpg and 258g/km – not far off the 550i petrol.When can I buy the new M5?
See it at a motor show in winter 2010-2011, with sales slated for spring 2011. Prices should rise with the tech, so pay around £70,000 for the new F10-series M5.