Luxury car maker Infiniti is on a drive to increase sales to executives with its new high performance M35 hybrid.

With its 306ps 3.5V6 petrol and 68ps electric motor it delivers a combined 374ps, which makes it the most powerful hybrid you can buy and gives the car a 0-62mph time of just 5.5sec, a limited maximum of 155mph but more significantly about 40mpg and with just 162gkm that falls into VED group G.

The standard seven-speed sequentia transmission offers not only automatic and semi-manual operation but you can select snow, sport, normal or eco modes, and when the last is chosen on the console switch it varies throttle response as well as steering effort. In eco-mode, Infiniti M35h can decrease consumption by 10pc with no effort on the driver’s part.

Infiniti’s clever technology with energy management also means when you brake heavily that additional power is delivered by the electric motor to shorten the stopping distance.

In purely electric operation the car also emits a warning sound to pedestrians, but for on obvious reason the UK Government has banned the sound being emitted when the M35h reverses.

The previous Infiniti models have nearly always been ordered in the highest Premium trim level (right) so the new M35h comes only in this trim level and the powertrain layout is not compatible with the 4WD available in the Sport level in any event.

Rarity is also a strong point as last year Infiniti sold about 400 cars in Britain and this year it expects to register 800 models, including about 50 M35h cars this year. In 2012, it is anticipated over 120 M35h models will be sold as the Infiniti dealer network expands from six in Reading, Piccadilly, Birmingham, Glasgow, Leeds and Stockport in 2011 to 12 all over the UK.

With a much larger network and new models in the pipeline which will take Infiniti into new market sectors and it has set a target of 20,000 sales by 2016 in Britain. It believes three-quarters of those will be business or fleet buyers.

First impressions

The Infiniti M35h makes a big impression at nearly 5m long and over 1.8m wide but the battery pack eats into the boot space (above) and it’s a modest 350 litres, which may be too little for some requirements.

Inside the cabin, however, it is a different story and the leg and headroom is good throughout for up to five occupants who can enjoy superbly comfortable yet supporting seats with their own heating and cooling systems.

The powertrain is a highly sophisticated system, silently starting in electric mode and moving seamlessly to engage the V6 petrol engine as required, or disengaging it as the computer decides to optimise economy.

Cruising along and seeing the engine tachometer suddenly drop to zero is initially disconcerting but power returns without hesitation when necessary.

The driver can select the usual three driving modes, eco, normal or sport and the car’s characteristics immediately change and its advantages become apparent if you select the energy management display on the big information screen and watch the systems working and economy fluctuating.

Power delivery is very strong and consistent, the gearchanges are silky smooth, the steering a little lacking in feel but the turning circle is good and the brakes very powerful. For such a modern car, however, it retains the US style foot operated parking brake rather than an electric system.

Noise levels are remarkably low, particularly from the powertrain and wind, and this makes the road rumble all the more noticeable despite the use of “white noise” to cancel most sources of naturally produced noise. I thought there must be a way to negate the road noise as well, but audibly there is not.

The Infiniti M35h is an extremely smooth riding and comfortable car but it all firms up in terms of responses and ride when you select the sport mode and it delivers the sharpness beloved of Infiniti owners. Even in this harder-edged setting it remains reasonably comfortable and is not bone-jarring.

Varying the driving modes I saw fuel consumption exceed 40mpg at best and overall it was about 32mpg, but that was around a predominantly urban test route.

For the driver who wants a sporting saloon with good passenger room but not huge bootspace the Infiniti M35h admirably fulfils the role but it really delivers more in terms of economy without compromising enjoyment.

Fact file  Infiniti M35h GT Premium                 £46,840                                Insurance group: 45

Against: Small boot, some road noise and lack of steering feel.