HYBRIDS have arrived at Infiniti with the luxury car maker introducing a petrol-electric powertrain on its executive saloon.

And in keeping with the brand's image of being upmarket with a difference, the M35h is no ordinary hybrid.

It's the fastest accelerating car of its type, knocking off 0 to 60mph in less than 5.5 seconds - and that's quicker than anything anyone has, even Porsche, has managed to develop so far using similar technology.

Better still, this creation from the posh arm of Nissan can average more than 40 to the gallon which is almost on par with a diesel engined BMW 5 Series.

Priced from £46,840 the Infiniti M35h is a major league player and available in the UK only in top specification GT Premium trim which includes as much high tech equipment inside as it does under the skin.

Standard features include a 30GB hard disk sat nav with a high definition display screen, a surround-sound Bose hi fi, an intelligent cruise control which is smart enough to lock on to and follow the car in front at low speeds in traffic and a full set of electronic safety devices which will even prevent the car drifting out of its lane.

There's also additional luxury touches such as air purification, double glazing, a heated steering wheel in addition to plush leather upholstery and classy white ash wooden veneers.

Putting all that into perspective means the Infiniti is high on value compared to its mainstream competitors from Jaguar, BMW, Mercedes and Audi where the bulk of such equipment would come as extras.

While the styling of the dash is akin to that of high end Mercedes there is a definite American feel to the M35h and that includes a foot operated parking brake which may not be to everyone's taste.

What cannot be questioned is the car's dynamics and it is delightful to drive. Well balanced and with responsive steering there is a surprising amount of feel at speed while around town it is smooth, quiet and refined.

The hybrid drive system is possibly the best around at the moment and key to its effectiveness is a high powered lithium-ion battery pack which enables the M35h to run purely on electricity even at motorway speeds.

Most other hybrids have less efficient batteries which mean they cannot manage such speeds and the lithium set up gives the Infiniti a major advantage in terms of fuel economy and exhaust emissions which, at 162g/km, are comparatively low for a petrol engined car of such proportions.

For business users that puts it in a lower tax band than many of its competitors and the M35h has a benefit in kind rating of 22 per cent

The M35h is powered by a 3.5-litre V6 engine developing 302bhp and an electric motor which adds a further 67 horsepower. The car has a seven speed automatic gearbox with a double clutch system to enhance performance resulting in a top speed of 155mph.

Driven gently it is relatively easy to achieve more than the 40.4 average mpg Infiniti claims. We managed 47 to the gallon during a run which took in inner-city traffic plus a 40 mile section at motorway speeds.

Maximum range on a single tank will be in excess of 700 miles - and that's not to be sneezed at in this class of car.

Like all hybrids the primary function of the electric motor is to assist the petrol engine enabling it to perform more efficiently.

Where possible the car switches into zero emission EV mode providing there is sufficient power in the batteries - which are recharged automatically on the move.

However, unlike some hybrid systems it is not possible to switch the M35h into EV mode manually and the hybrid set up operates automatically at all times.

That said, on our drive the car regularly switch into EV - and a readout on the trip computer revealed that of the 5,000 miles this M35h had completed since new, 1,100 miles had been on battery power - an impressive fuel saving.

If needs be the M35h can be driven as enthusiastically as any V6 exec mobile - and under acceleration there is a lovely exhaust note only a V6 can create - but while it is enjoyable it won't be so kind on your pocket.

One compromise of the hybrid system is the boot space is reduced from 500 litres on a regular Infiniti M saloon to 350 litres on the M35h to accommodate the battery pack - but it is still possible to fit in a couple of good sized suitcases.

In general the M35h will run silently on electricity at slow speeds, and will switch off when stationary, but to alert pedestrians while the vehicle is running on battery power there is audible warning from the front of a car - an unobtrusive whooshing sound which is generated at speeds of up to 20mph.

Infiniti is the first in the world to use such a warning system which further demonstrates how well thought out this hybrid is.

It offers great fuel economy without compromising performance and with such levels of equipment and refinement included in the price, the M35h is something of an eye opener.