The public debut of the new M5 could have been akin to an oil spill in an ecological paradise, had the monstrous CO2 output of the old one been carried over. No such fear. This is, after all, modern, EfficientDynamics-obsessed BMW.
So while the F10 M5 gains 10hp for a Mercedes E63 AMG-clobbering 560hp peak power figure it also becomes 30 per cent more fuel-efficient. Perhaps as a riposte to those who criticised the previous V10 car's peaky delivery there's also 30 per cent more torque, available from just 1500rpm.
Thank the new 4.4-litre twin-turbo V8 engine. Yes, say the engineers, it's based on that in the X5M. But don't sigh, for it's been extensively re-engineered and, as the 1-series M proves, BMW has clearly nailed how to make turbo engines worthy of the M badge.
The front vents appear big enough for show-weary hacks to curl up and have a snooze in. But they are the most OTT part of an otherwise discreet super-saloon and simply supply roomfuls of air to an engine that gorges on it. How can just 232g/km CO2 come out the other end then?
It's bafflingly eco. And, with an Active M differential and M5-first EDC suspension adding to the handling promise too, this may well turn out be the most extreme example of EfficientDynamics yet seen.