BMW unveils world's most powerful hybrids

The ActiveHybrid X6 and the ActiveHybrid 7 are BMW's answer to the Toyota Prius, though don't be fooled into thinking the pair are anything other than high performance executive cars - both are powered by V8 engines, but use electric hybrid technology to post impressive economy and CO₂ emissions figures while boosting performance.

First the X6 ActiveHybrid, which BMW claims is the most powerful hybrid ever produced. It's difficult to argue with that too, given its astonishing 479bhp and 575lb.ft of pulling power, which puts clear water between it and the Lexus RX450h. The newcomer is capable of a 5.6-second 0-62mph sprint, yet posts CO₂ emissions of 231g/km and economy of 28.5mpg combined. Its 4.4-litre petrol engine is mated to two electric motors that allow it to be driven on electricity alone for 1.6 miles at up to 37mph, or combine with the V8 to result in its massive performance.

The ActiveHybrid 7, on the other hand, has only one electric motor and works slightly differently. It can't be driven on electricity alone, but the motor backing up its V8 petrol engine gives it an overall economy and emissions advantage over the X6. It's capable of 29.1mpg but will demolish 0-62mph in just 4.9 seconds while emitting 219g/km of CO₂, which makes it quicker than the 750i but much cleaner at the same time.

Both cars will be unveiled at September's Frankfurt Motor Show, though neither is coming to the UK because we won't buy enough of them here to make it economically viable.

Mark Nichol