2010 will come to be known as the turning point for environmentally responsible, alternative-energy motoring – it was the year when high-performance sporting brands made hybrid and electric powerplants cool. Porsche revealed the 911 GT3 R Hybrid, sent it out to compete with the big guns at the Nürburgring 24 hours and in ALMS and in doing so, showed that ‘green’ doesn’t mean slow.

Since then we’ve seen Porsche’s 918 Spyder and RSR appear, Jaguar’s C-X75, BMW’s Vision EfficientDynamics sportscar and many other KERS-enabled (kinetic energy recovery system) concept vehicles. Yes KERS, the controversial system that was widely criticised when it entered F1 in 2009 has migrated very quickly into other forms of motorsport and will soon be appearing in passenger cars that you or I can choose to drive.

And the connection could not be any more direct – Williams F1 who raced with KERS in 2009 subsequently bought the engineering company which provided the technology, now called Williams Hybrid Power, it lists a certain Patrick Head on its Board of Directors and this same Oxfordshire company provides the hybrid power systems used in Porsche’s 911 GT3 R Hybrid and 918 Concept.

It’s a great example of F1’s potential to spawn technology which benefits everyday road cars, not just in enhancing performance but also for bring forth significant efficiencies in the way available power is used.

The Infiniti M35h

It’s with this in mind that I found myself reading another tale of alchemy, as Infiniti announced its first hybrid powered car and the most powerful new member of the luxury Infiniti M family. Infiniti are also claiming the M35h to be one of the fastest and greenest V6-powered saloons available.

Available throughout Europe from the spring (depending on country), Infiniti’s first Direct Response Hybrid car to go on sale can be summed up by four figures: 359 bhp (268 kW) combined petrol/electric power; 5.5 seconds acceleration from 0 to 62mph, 162 g/km of CO2 emissions and 40.4mpg on the combined cycle.

The Infiniti M35h’s innovative one electric motor/two clutch hybrid system is complemented by the Infiniti hallmarks of low drag – the Cd is down to an impressive 0.26 – and lighter weight, the M35h weighing less than its M30d diesel sibling at 1830kg.

The new Infiniti flagship to compete at the heart of Europe’s executive class has the additional claim to fame of outstanding cruising fuel economy with 49.56 mpg on the extra urban cycle – impressive for a near 5m-long luxury saloon with a 155mph top speed and acceleration to embarrass many sports cars.

The Infiniti M35h’s near-50mpg extra urban consumption is 10mpg ahead of its main hybrid rival, while in the VED stakes its place in B and G is two bands lower, cutting the first-year rate of road tax for the Infiniti almost in half, from £300 to £155. Similarly the M35h’s lower CO2 results in more affordable company car tax bills, with a liability in 2011/12 of 23% rather than its less powerful rival’s 26%.

The combination of high performance and low emissions is the direct result of a 67 bhp (50 kW) electric motor that Infiniti claim can power the Infiniti M35h more often, at higher speeds and for longer periods than rival hybrids.

The Infiniti M35h becomes the world’s first hybrid to feature an audible pedestrian warning system as standard. Instead of just a single tone, a range of high-low sounds at different volume levels was chosen, the noise sweeps from high to low frequency depending on vehicle speed and whether the M35h is accelerating or decelerating.

Capable of cruising on emissions-free electric power alone at speeds up to around 50 mph, Infiniti’s Direct Response Hybrid system extends the hybrid’s advantage from slow-moving city traffic to the open highway. In real-world testing the Infiniti M35h has shown it can drive in electric-only mode for as much as 50% of the time on mixed routes. Even energy normally lost in deceleration or under braking is saved to help keep the batteries charged up.

Despite running in silent electric mode at every opportunity, the Infiniti M35h cannot surprise pedestrians and the visually impaired as it approaches thanks to Approaching Vehicle Sound for Pedestrians (VSP). VSP emits a pleasing, non-intrusive sound that varies in pitch and volume at vehicle speeds up to 19 mph.

Innovative Hybrid Electric Power Steering (NH-EPS) and regenerative brakes, both developed especially for the Infiniti M35h in order to further boost its efficiency, are key technology highlights. The Infiniti M35h’s petrol engine is a 3.5-litre V6 with 302 bhp (225kW). It is part of the same family of V6s as the 3.7-litre unit in the M37 but with torque characteristics to complement the low-down pulling power – 270 Nm at 1770rpm – of the electric motor.

The Infiniti M35h is just as luxuriously trimmed and equipped as the other Infiniti M models while its 350-litre boot is capable of storing four golf-bags or two large suitcases.

Prices for the Infiniti M35h , which will be offered in either GT or GT Premium grades, are due to be announced before the Geneva Motor Show.