Now we are five. The arrival of the G37 Convertible – in which the ‘G' could easily stand for Gorgeous – brings to five the number of different models in Infiniti's expanding European portfolio.

The G37 Convertible has been designed from the outset with one goal in mind: to excite the senses. The stunning silhouette is perfectly proportioned, looking just as beautiful with the three-piece folding hard-top up or down, while the performance promised by the potent 3.7-litre V6 engine is guaranteed to delight.

"The new G37 Convertible is that rare thing: an open four-seater with a retractable hardtop whose styling isn't compromised by an awkwardly elongated trunk. We have taken the conscious decision to sacrifice a little practicality in exchange for a great deal of style," said Jim Wright, Vice President, Infiniti Europe.

"The new G37 Convertible is a perfect example of ‘Inspired Performance', a theme that runs through the entire Infiniti range. It offers a unique combination of seductive style with genuinely thrilling performance and unrivalled luxury and features. It will appeal to a discerning audience who appreciate the better things in life," he added.

G37 Convertible at a glance

  • Uncompromised design
  • Three-piece retractable hardtop
  • Four seats with standard leather upholstery
  • 320PS 3.7-litre V6
  • Six-speed manual or seven-speed automatic
  • Rear-wheel drive
  • Dual-zone adaptive climate control with auto re-circulation
  • Standard rear parking camera and wind deflector
  • GT Premium grade with:
  • High resolution touch screen display
  • Hard disk drive navigation system with built-in MICHELIN guide
  • 10GB Music Box powered by Gracenote® music database
  • Bose® Premium Sound System with front headrests speakers
  • Heated and ventilated front seats
  • Unique colour and trim options
  • Orders from June with first deliveries from September 2009

G37 Convertible in detail

When the decision was made to create an open-top version of the svelte G37 Coupé, Infiniti's designers and engineers weighed up the two options. Should they go for the relatively straightforward and cheaper option of a soft-top, or a practical and refined if more complex folding hard-top.

The argument for and against raged for some time, but it was eventually settled by the target audience itself. Market research indicated that while they loved the concept of ‘wind-in-the-hair' motoring, potential buyers were concerned by the security and safety issues that go hand-in-hand with a traditional fabric roof.

A folding hard-top, on the other hand, gives all the roof open benefits of a soft-top, but also delivers Coupé-like security and comfort with the roof closed. There is less risk of inner-city vandalism, while the hard-top solution is clearly more technically advanced than a fabric roof and more in keeping with a premium brand like Infiniti.

"With a folding hard-top, the driver can choose whether he or she wants to drive a Coupé or a Convertible. With a fabric roof they are always driving a soft-top," said Bastien Schupp, Marketing Director, Infiniti Europe.

But creating a folding hard-top that looked as good as the stylish G37 Coupé would be the next target…

Infiniti G37 Convertible (2009)
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Design

The trouble with most hard-top convertibles on the market is that their overall proportions are distorted by the need for a longer trunk to package the roof folding mechanism and allow a modicum of luggage space when the roof is folded away.

Usually, their design falls between two stools. Whether the roof is up or down, the looks are compromised, while trunk space is always at a premium when the roof is stored. Infiniti designers took a more pragmatic view.

Rather than compromise the looks of the car – style is the single most important factor in the buying process of a convertible – they simply accepted that luggage space was unimportant when the car was driven with the roof down.

When travelling longer distances with a trunk full of suitcases – on a touring holiday, for example – the journey would be undertaken with the car in Coupé mode. But once the destination had been reached and the suitcases unloaded, the full joys of open-topped motoring could be experienced… and if there was little luggage space in the trunk, well that really didn't matter.

In fact, the new G37 Convertible is rather more practical than the designers' brief suggests. With the roof up, at 366 liters the luggage area is actually bigger than that of the G37 Coupé and a similar size to best-selling competitors.

With the roof down, there is still space in the trunk to store the wind deflector and a slim bag. Plus if the rear seats are not occupied and the wind deflector is in place, the space underneath can be used as a luggage shelf.

Because the car looks as good with the roof up as it does with the roof down, Infiniti refers to the Convertible's ‘dual beauty'. This was to be the guiding motivation during its conception.

The G37 Convertible maintains the taut proportions of the coupe with length and height increased by only 5mm. The muscular stance is even enhanced by a wider track at the rear. From the A-pillar backwards, every element of the car has changed. Designed and built in Japan, the aluminum hard-top capsule is of a three piece ‘clamshell' design. This allows the silhouette of the Coupé to be maintained when the roof is up, but also permits a short rear overhang and a low boot lid. Inside, the headlining is fabricated in one piece with no joins for a more cohesive look.

Thanks to slimmer C-pillars and correspondingly larger side windows, rearward visibility with the roof up is notably better than would have been the case with a fabric roof. Engineers paid a lot of attention to provide an airy cabin feel with good all round visibility even with the roof up

It takes around 25 seconds for the roof to be lowered or raised as the operation needs just a single push on a button ideally located on the centre console. Alternatively, working in conjunction with the Intelligent Key, a switch on the driver's door allows the roof to be opened from outside the car simply by pressing and holding the unlock button on the door handle. Careful engineering has ensured that water ingress is minimised when the roof is lowered after a rain shower.

The G37 Convertible shares many signature design cues with other Infiniti models, notably the flowing front curves, wave-style bonnet, expressive double arch grille and L-shaped Bi-Xenon headlights with integrated fog lamps. Behind the A-pillar, however, the roof, doors, rear panels and trunk lid are all unique to the Convertible. To accommodate the folded roof, the rear of the car is 32mm wider than the Coupé and a mere 5mm longer.

To ensure ride comfort, handling and refinement are uncompromised, the sills and other structural elements have been strengthened and the rear track widened. The rear suspension, too, has been modified. A steering column damper has been added to eliminate the possibility of scuttle shake over poor surfaces. This, combined with the car's added strengthening, gives the G37 Convertible impressive structural rigidity. These changes, added to the folding roof mechanism, result in a contained 180kg weight increase over the Coupé version.

Weight distribution is virtually unaffected by the folding roof. In Coupé mode, the split is 53/47 front to rear which changes to 52/48 when the roof is folded away.

Design features unique to the Convertible include the tail-lights, which have an inner ‘circle of light' for greater distinction at night, the rear bumper and chrome detailing. The trunk lid finisher incorporates both the high mounted stop lamp and the camera for the rear parking monitor.

Inside, new materials and colours combine to ensure the sophisticated cabin is as good to look at as the exterior. The driver-oriented cockpit features the Infiniti signature ‘double wave' instrument panel design with white and violet illumination, integrated multi-function drive computer and analogue Infiniti clock. The double-stitched leather covered steering wheel incorporates standard audio and cruise control buttons.

New leather shades include a pale brown called ‘Wheat', a lighter ‘Stone' colour and a bold ‘Monaco Red' to complement the existing dark ‘Graphite' which is also found in the Coupé. Trim options include the technical feel of ‘Silk Obi' aluminum inserts – inspired by fine Japanese silk – or two wood finishes, Red-stained Maple Wood and African Rosewood. The trim panels found on the dashboard and doors are inspired by the shape of Japanese spears.

There are eight exterior colours – two solids and six metallics – and include two shades unique to the Convertible: light blue called Pacific Sky, and a deep red called Midnight Garnet.

Engine and powertrain

The G37 Convertible's power plant is the now familiar 3.7-litre V6 engine that also drives the G37 Coupé and Sedan. A potent, high revving unit, the 24-valve twin cam V6 produces 320PS and 360Nm of torque to make it the most powerful naturally aspirated 6 cylinder engine in its class.

The all-aluminum unit features a rigid two-part bed-plate construction for greater refinement and rigidity. This added rigidity allows sustained use at higher revs –the V6 is red-lined at 7,500rpm – but the key to the engine's turbine-like ‘swell' of performance is its exceptional torque delivery.

Central to this is the use of Infiniti's proven Variable Valve Lift and Event (VVEL) technology. VVEL combines hydraulically controlled variable valve timing and electronically controlled variable valve lift on the intake side to improve performance – peak torque is available over 90 per cent of the engine's rev range – and throttle response. It also helps lower emissions and enhances fuel efficiency when compared to a conventional system. Emissions are further improved by rapid warm up of the catalyst.

The result is a progressive rush of acceleration rather than the peaky power delivery typically found in smaller, turbo-charged engines.

In keeping with the G37 Convertible's sporting potential, the engine delivers an aural soundtrack that's especially intoxicating when the roof is lowered. The exhaust note has been created by fine tuning the equal length tubular manifolds and symmetrical exhaust system to deliver the perfect balance between low and high frequency sounds.

Standard transmission is a close-ratio six-speed manual, but an advanced seven-speed automatic is optionally available. Expected to account for around 65 per cent of sales, the auto option is one of the most advanced transmissions on the market. With one extra ratio compared to most of its automatic rivals, the transmission packs six gears for outright performance with the seventh tuned to provide greater fuel economy and quieter cruising at motorway speeds. It comes as standard with twin steering wheel-mounted magnesium paddle shifters and includes Adaptive Shift Control, Drive Sports (DS) and manual modes. It also incorporates downshift rev matching providing automatic blips of the throttle when changing down in manual mode.

On both manual and automatic transmission, maximum speed is electronically limited to 250 km/h. On manual version 0-100 km/h takes just 6.2 seconds and returns 11.9 l/100km over the combined cycle while the official CO2 figure is 275 g/km. The automatic version achieves 0-100 km/h in 6.4 and returns 11.4 l/100km over the combined cycle while the official CO2 figure is 264 g/km.

Chassis

The high levels of responsive handling that have come to be expected from a car wearing the Infiniti badge are all present and correct on the G37 Convertible. Like the G37 Coupé, the Convertible uses Infiniti's advanced Front Midship (FM) chassis technology. This places the compact V6 in the front of the car with drive going to the rear wheels, but mounted as low and as far back as possible, with most of the block behind the front axle line. The result lowers the centre of gravity and helps to deliver the optimum front to rear weight distribution.

Fully independent suspension uses lightweight aluminium components to reduce weight. A double wishbone design with a single pivot lower wishbone and a long upper link can be found at the front with a multi-link arrangement behind. Separating the rear springs and dampers allows the shock absorbers to be mounted in line with the wheel centre helping to minimise alignment changes and reducing friction for more nimble handling and smoother riding characteristics.

Fine tuning of the chassis takes into consideration the extra weight of the G37 Convertible and the likely driving styles of owners to give a more compliant ride with a minimum reduction in handling sharpness. Ride comfort is enhanced by the adoption of Dual Flow Path rear shock absorbers – generating a smoother ride and less impact shock over uneven surfaces.

Responsive steering includes an advanced speed sensing system, while the standard sports braking system have vented discs at all four corners with a four channel, four sensor anti-lock system, Electronic Brake Force Distribution (EBD) and Brake Assist. It has larger discs than the standard G37 Coupé (355mm front and 350mm rear) with aluminium four-piston callipers at the front and two-piston callipers at the rear. All callipers are embossed with Infiniti lettering.

Also standard on both versions of the G37 Convertible are striking 19-inch alloy wheels. The ten-spoke rims are shod with high performance tyres (225/45WR19 at the front and 245/40WR19 behind).

Other standard active safety features include switchable Electronic Stability Program (ESP) and Traction Control. Passive safety features include fixed rear head restraints with integrated pop-up roll-over hoops, strengthened windscreen surround and a total of 6 airbags.

Equipment and grades

Both versions of the G37 Convertible offer exceptionally generous levels of standard equipment. Indeed, so well equipped are the GT and GT Premium grades that aside from paint, colour and trim choices, the options list is restricted to just three items – the seven-speed automatic transmission, intelligent cruise control and a temporary spare wheel.

It means the G37 Convertible is equipped as standard with a host of performance, safety, comfort and convenience features unsurpassed in its class. Examples of each include the 19-inch alloy wheels; adaptive front lights; leather-covered powered and heated front seats; and the rearview parking camera. But there's much, much more.

Evidence of the careful thought that's gone into the development of the G37 Convertible can be found in the features designed to enhance life in the cockpit, roof up or down. These include advanced dual-zone adaptive climate control with auto recirculation.

Adaptive climate control means just that: air conditioning that automatically adjusts its performance depending on whether the roof is raised or lowered. In the summer, fan speeds rise to increase the volume of cooling air circulating in the cabin as the outside temperature rises, maintaining upper body comfort. When the roof is down, the volume of cooling air increases by 10 per cent as the car's speed decreases.

In winter, as the outside temperature drops so the volume of heated air in the cabin increases again to ensure upper body comfort is maintained. The system incorporates automatic recirculation allowing clean air into the cabin but blocking out polluting exhaust gases. An integrated polyphenol filter traps dust, deactivates allergens and cleans and deodorizes the incoming air.

In common with many other open-top cars, the G37 Convertible has a wind deflector which fits behind the front seats to minimize turbulence and which is removable when the rear seats are occupied. Unlike many other open-top cars, however, the G37's deflector is a standard feature and not an extra cost option.

The seats are upholstered in leather while the front pair features eight-way power adjustment. The driver's seat also has a lumbar adjustment, while thanks to the lack of a B-pillar, the front seats in both versions incorporate a special loop on their outer shoulder to ensure the seat belt is held in the correct position for optimum safety.

Finding the perfect driving position, meanwhile, should be easy thanks to standard power rake and reach adjustment for the multi-function steering wheel.

The G37 Convertible is also the first vehicle in the range to feature Infiniti's new infotainment system called Connectiviti.

Standard on the GT grade, it includes a powerful audio system, incorporating a CD player with MP3/WMA disc compatibility as well as a fully integrated 2GB Music Box enabling owners to create playlists and record CDs on the hard disk rather than having to carry them around. USB connectivity allows full control of audio devices such as iPod from the multi-function steering wheel and the control panel. The device is charged whenever it is plugged in and ignition on. Alternatively, all audio devices can be played via an Aux-in socket.

Mobile phone connectivity is via Bluetooth® with voice recognition. Hands-free operation is possible via a built-in microphone and one of the audio system's speakers. All audio and phone functions can be accessed via controls on the steering wheel.

Parking will never be a problem thanks to front and rear sensors… and a rearview camera linked to a full colour monitor in the centre of the dashboard.

The adaptive front light system (AFS) links powerful Bi-Xenon headlights with steering inputs so the lights automatically follow the path of the front wheels, providing a wide spread of lights around corners and along winding country roads.

Other features include a cruise control, aluminium pedals and foot-rest and the Infiniti Intelligent key with smart access and push button ignition. Aside from the seven-speed automatic transmission with paddle shifters, the only major option is Intelligent Cruise Control. ICC uses brake, throttle and laser sensors to help maintain a set distance between the Convertible and the car in front.

On automatic transmission models, the software reduces driver's workload even more in the low-speed driving range allowing ICC to work from 0km/h thanks to the "Full Speed Range" feature. ICC also identifies emergencies using the laser sensors to determine distances and closing speeds to a car in the same lane ahead and prepares the Brake Assist system before the driver starts braking. If the driver must take immediate action to avoid a collision, the system sounds a warning to prompt driver action or can even activates the brakes to decelerate the vehicle.

The GT Premium grade offers all this… and yet more. The driver seat has ten-way power operation with electric control for lumbar adjustment. More significantly, the front seats are both heated and cooled, the latter feature being especially welcome if the car has been left parked in the sun with the roof down.

The Infiniti Intelligent key is upgraded to include memory settings for the driver's seat, steering column and door mirrors.

But perhaps the biggest upgrade is to the infotainment system where the GT Premium grade receives a new advanced navigation and entertainment system called Connectiviti+.

At its heart is the latest HDD (hard disk drive) navigation system with a remarkable 30GB of memory space for faster operation and richer content. Among the benefits are vastly extended mapping of 42 countries, which now includes Turkey, Eastern Europe and Russia, as well as a 3-dimensional navigation guide with improved graphics and a more realistic depiction of the road ahead such as intersection in major European cities.

Real time traffic information is delivered via RDS-TMC, but quicker operation allows the system to offer re-routing in seconds. Thanks to its 30GB hard disk drive data storage potential, the rich content of the navigation system has been expanded.

Users have access to POI (Point Of Interest) information supplied by the MICHELIN guide (hotels & restaurants) and Michelin Green guides with pictures and comprehensive information on museums and other tourist attractions in more than 25 countries (including cities like London, Paris, Berlin, Rome, Madrid, Frankfurt, Barcelona, Vienna, Milan) and 6 languages. In addition, the Michelin database is able to provide further general tourist information. The system contains up to 7200 pictures and more than 100 specific tourist tours on a specific region.

In addition to control panel, steering wheel controls and voice recognition capability, the infotainment system can now also be controlled via a touch-screen display. This multi-control interface adds greatly to ease of use.

On-screen instructions can be displayed in eight different languages – English, French, German, Spanish, Italian, Portuguese, Dutch and Russian – while voice recognition is supported in seven – English, French, German, Spanish, Italian, Portuguese and Dutch.

Another benefit is the incorporation of a 10GB hard drive Music Box which can store music from up to 300 CDs. Song titles, album cover and artist information is now displayed on the screen thanks to Gracenote® music database built-in into the new infotainment system. Connectiviti+ also supports iPod/USB integration with full control via the navigation screen, steering wheel switches or control panel. The device is charged whenever it is plugged in and ignition on.

Alternatively, audio devices can be played via an Aux-in socket or via Bluetooth® audio streaming, while playback of high quality DVD music or DVD videos is also supported when the car is parked. Photo/Audio/Video files can also be played on the screen from standard USB sticks.

Enhancing the audio experience still further is the Bose® Premium Sound System. As with Bose systems found in other Infiniti models, the Convertible sound package has been specifically tailored to suit the acoustic characteristics of the model and optimises music reproduction by changing the equalization whether the roof is up or down.

But the audio system from Bose in the G37 Convertible takes things a stage further with a unique feature: Bose Personal® speakers. Personal speakers are installed in the front-seat headrests and are combined with proprietary Bose® signal processing circuitry. This helps provide a more consistent audio environment, even when the convertible top is down or windows are lowered. This exclusive Bose innovation enhances the width, depth and spatial clarity of the soundstage and provides improved spectral balance. This pair of 50mm speakers integrated in both front headrests takes the total speakers count to 13.

The sound system also incorporates Bose AudioPilot® 2 noise compensation technology that helps preserve the listening experience by reducing the effects of unwanted outside sound. More effective than conventional speed sensitive volume system, this Bose innovation automatically monitors and compensates for the effects of unwanted outside sound and vehicle speed.

The system also includes two Nd® woofers using Neodymium magnets that deliver the output of much larger speakers while being slim enough to be mounted in places where ordinary woofers might not fit.

Neodymium magnets also are used in other select speakers to help deliver full sound while reducing system weight.

Finally, the handsome lines of the G37 Convertible will stay looking good thanks to Infiniti's clever Scratch Shield paint. Scratch Shield incorporates a highly elastic resin within the conventional clearcoat to increase the paint's flexibility, allowing it to ‘heal' scratches. A car with Scratch Shield paint can exhibit up to five times fewer scratches than one with a conventional clearcoat when exposed to the same conditions.

Standard features at a glance

G37 Convertible

GT:

  • 19-inch alloy wheels and sports brakes
  • Leather upholstery
  • 8-way powered and heated front seats
  • Manual lumbar support on driver's seat
  • Adaptive Bi-Xenon headlights
  • Infiniti Connectiviti infotainment system with:

- Front and rear parking sensor - Rearview parking camera - Bluetooth® mobile phone connectivity - Seven speaker audio, with CD player and 2GB Music Box - USB/iPod connectivity - Aux-in

  • Dual-zone adaptive climate control with auto-recirculation
  • Wind deflector
  • Cruise control & speed limiter
  • Infiniti Intelligent Key
  • Power reach and rake steering wheel adjustment
  • Aluminum pedals
  • Scratch Shield paint

GT Premium

As GT grade, plus:

  • 10-way powered driver seat
  • Heated and cooled front seats
  • Electric lumbar support on driver seat
  • Memory settings for driver's seat, steering wheel and door mirrors (linked to I-key)
  • Infiniti Connectiviti+ infotainment system with:

- Touch screen high resolution display - 30GB HDD navigation system - Traffic information, Michelin POI guide, 3D display - CD/DVD player & 10GB Music Box - Bluetooth® wireless audio streaming - Built-in Gracenote® music database - Voice activation and touch screen for navigation and audio

  • 13-speaker Bose® Premium Sound System with front headrests speakers and noise cancellation technology

Options

  • Seven-speed automatic transmission with paddle shifts
  • Metallic paint
  • Intelligent Cruise Control
  • Temporary spare wheel
  • Monaco Red leather upholstery and red stained Maple Wood interior trim (only on A/T)
  • African Rosewood interior trim (only on A/T, not available with Stone upholstery)

Tuned for Europe

Although the G37 Convertible was designed and engineered and is built in Japan, Infiniti's Technical Centre at Cranfield in England influenced the final specification of the car to be sold in Europe.

While many of the developments engineered at Cranfield were made to ensure the car conformed to European legislation, there were a number of significant changes made to the chassis set-up to suit Europe's higher average speeds and road types.

Subtle changes have been made to the chassis stiffness – the Convertible is slightly softer than the Coupé for greater ride comfort – while European models have a unique steering rack to enhance lane change stability and provide greater steering linearity at speed.

Fine tuning of the dampers has increased body control for Europe's twisty country roads and further enhanced the car's flat cornering characteristics.

Conclusion

The Infiniti G37 Convertible has a hedonistic spirit. Its refined performance and undeniable style deliver similar thrills to the acclaimed G37 Coupé, but with the opportunity for those sensations to be heightened still further when the roof is lowered.

"The G37 Convertible is a car to fall in love with. It's as simple as that," said Jim Wright, Vice President, Infiniti Europe.