July 19 2006 At the 2006 British International Motor Show which opens today, Mazda has unveiled a new version of its motoring icon, the Mazda MX-5 Roadster Coupe, and it opens up a new dimension of fun and versatility for people who love open-top sports cars. The Mazda MX-5 Roadster Coupe is a brand-new counterpart to the third-generation MX-5, which launched in 2005. It has the same responsive performance and emotive styling as the soft-top model, but is equipped with a Power Retractable Hard Top—an electrically retractable hard top that doesn’t sacrifice any boot space. The roof retracts in three sections into a space behind the seats, leaving the boot completely unaffected and it does so very quickly in just 12 seconds (Mazda claims this is the quickest of any electrically retractable hard top on the market today), so it doesn’t interrupt driving enjoyment for long. And the entire mechanism has only marginally added to the weight at just 37 kilos more than the ragtop.
Since its launch in 1989, the Mazda MX-5 has been a smash-hit product around the world. It’s so popular that it holds a place in the Guinness world records as the world’s top-selling lightweight, open, two-seater sports car, and it has won over 150 industry awards around the globe. Demand is as strong as ever and by the end of May 2006, cumulative production stood at 769,454 units.
The current MX-5 — the third generation of this modern motoring icon — made its global debut at the 2005 Salon International de l’Auto in Geneva. It’s an uncomplicated open-top, lightweight sports car in which Mazda further evolved the Jinba Ittai-focused dynamics of the previous MX-5 generation for even greater driving enjoyment. And sports car enthusiasts around the world have overwhelmingly endorsed it.
Customers’ high evaluation of the third-generation MX-5 has been echoed in the form of many prestigious industry honours including the Car of the Year Japan 2005–2006 award, Wheels magazine’s 2005 Car of the Year award, BBC Top Gear magazine’s Roadster of the Year 2005 award, a Car and Driver 2006 10 Best Cars award, and selection as one of top three contenders for the 2006 World Car of the Year award.
The goal with the MX-5 Roadster Coupe was to further heighten the fun of the third-generation MX-5 open-top driving experience by incorporating a hard top equipped with a user-friendly open/close system. Realizing this goal meant also delivering the Jinba Ittai-focused dynamics that make the MX-5 fun to drive and the distinctive roadster design that make it fun to look at.
The light, compact, stiff body that forms the basis of Jinba Ittai-focused dynamics benefits from an optimally light, compact roof and from reinforcements that stiffen the body opening without creating excessive weight. The low yaw-inertia moment needed in a lightweight sports car benefits from the weight distribution yielded by storage of the roof in the cabin (as opposed to storage of the roof in the boot) where it’s close to the centre of gravity.
A light, compact body, a low centre of gravity, a low yaw-inertia moment, and the optimal front-rear weight distribution realized by a front-midship engine layout yield incomparable controllability .
The MX-5 Roadster Coupe is only 37kg heavier than the soft-top model. Although adopting the Power Retractable Hard Top made more weight unavoidable, the overall weight increase was kept as small as possible by steps taken to minimize component weight and reinforce the body for ample stiffness without greatly increasing the weight.
Further, the MX-5 Roadster Coupe is equally as compact as the soft-top model. An increase over the soft-top model of 10mm in the overall height with the roof closed is the only dimensional difference.
The body opening used to accommodate the retracted roof is bigger than the corresponding opening in the soft-top model. Making the opening larger compromised body stiffness, so to compensate, the rear of the body has newly specified reinforcements, which are all designed to add the greatest possible structural strength with the smallest possible weight penalty. Overall body stiffness is on a par with that of the soft-top model.
The MX-5 Roadster Coupe has nimble, linear handling characteristics that are every bit as enjoyable as those of the soft-top model. However, the handling is different in a way that suits the new model’s more refined character.
Owing to the relatively heavy roof, the MX-5 Roadster Coupe’s front/rear weight distribution and the height of its centre of gravity differ from those of the soft-top model. Also, the balance of stiffness between the front and rear of the body differs from that of the soft-top model. To minimize the impact of these factors on Jinba Ittai performance, Mazda optimized the suspension damper and spring settings.
The result of the design revisions is handling that’s characterized not so much by the briskness that distinguishes the soft-top model but more by characteristics that give a refined-feeling ride. The MX-5 Roadster Coupe’s movements feel slightly gentler than those of the soft-top model; drivers and passengers perceive a relatively smoother, milder road feel.
Toward the rear of the body, essential design adjustments were made to accommodate the Power Retractable Hard Top without compromising the car’s identity. Most crucially, incorporating the roof so it could be retracted into the cabin (behind the seats) without affecting the boot space necessitated a rear-deck structure different from that of the soft-top model. Also, achieving a good visual balance between the body and roof demanded several design adjustments at the rear of the body.
Aside from an electrically powered rear deck cover, the most visible differences from the soft-top model lie in the contours of the rear fenders and boot lid and in a new design for the high-mount stop lamp. The rear combination lamps and rear bumper are the same as those of the soft-top model.
The rear deck cover makes the front edge of the rear deck 40mm higher than the corresponding edge on the soft-top model. For an optimal height balance across the rear deck, the boot-lid design positions the trailing edge of the rear deck 20mm higher than the corresponding edge on the soft-top model. The new design makes the tail look sharper and more ‘pulled up’ than that of the soft-top model.
To create a visual balance with the relatively high rear deck without compromising the car’s low-slung roadster look, the rear fenders are more prominently contoured toward the top than those of the soft-top model. The powerful-looking rear end strikingly complements the neat, sleek lines of the closed roof.
Light, highly formable plastics permitted a high degree of design freedom with the roof. As a result, the roof is shaped to look compact and stylish in a way that distinguishes the MX-5 Roadster Coupe from other cars and allows users to enjoy the same sense of agility that’s communicated by the soft-top model during closed-top driving.
The roof’s tautly curved form makes the cabin look compact, and its rear edge is shaped to flow toward the horizontal for a look of speed. The rear window has a printed heating element and is slightly larger than that of the soft-top model for enhanced rearward visibility.
The body has exclusive features that emphasize its premium quality and set the MX-5 Roadster Coupe apart from the soft-top model. Perhaps most noticeably, various body parts have chrome plating, which adds refinement to sportiness (the availability of chrome-plated parts differs by market). Also, the high-mount stop lamp looks sleeker and more refined than that of the soft-top model thanks partly to a slimmer design and partly to a white (as opposed to red) lens.
The interior design is completely consistent with that of the soft-top model; it creates an environment that exudes the MX-5’s sporty, fun-to-drive roadster personality.
As with the soft-top model, the interior trim is available in three packages: one based on saddle-tan leather, one based on black leather, and one based on black fabric (availability differs by market).
The only noticeable difference from the soft-top model at the front of the cabin is the addition of ‘open’ and ‘close’ buttons and an indicator lamp (to control and monitor operation of the roof) near the top of the centre stack of the instrument panel. The buttons are easy to reach from the driver’s seat.
The back trim differs slightly from that of the soft-top model: There’s no roof-opening-hook lever between the seats, and the trim does not incorporate storage recesses behind the seats because of the incorporation of the roof storage space between the trim and the boot.
The seats are the same as those of the soft-top model, so a seatback pocket is provided.
In pursuit of a smooth, compact retraction arrangement that would neither compromise the MX-5’s distinctive roadster styling nor involve a major weight increase, many concepts using a variety of component shapes, materials, and activation mechanisms were tried. A new combination of light, highly formable and stiff plastics for the roof sections was a big part of the solution.
Roof-opening and roof-closing operations are initiated using buttons that flank the hazard-warning button and with reference to an indicator lamp that’s located beside the buttons. The operations are quietly effected by two roof motors and two rear-deck motors, which are all controlled by a dedicated electronic control unit.
The user must manually apply a centre lock (this is identical to that of the soft-top model) to retain the roof after closing it. And the user must release the centre lock before opening the roof. These requirements help to enhance safety. The indicator lamp allows the user to check whether the roof is presently locked or unlocked.
If the user releases the ‘open’ or ‘close’ button part-way through a roof movement, the indicator lamp comes on and warning beeps are emitted for 10 seconds as a safety warning.
Whereas electrically retractable hard tops on cars made by other companies use boot space for roof storage, Mazda’s unique Power Retractable Hard Top leaves the boot space untouched by retracting entirely within the cabin. Consequently, luggage capacity is not compromised and roof-opening and roof-closing operations can be performed quickly and easily. The speed and ease with which the roof can be opened and closed, regardless of luggage, minimize interruptions in driving enjoyment.
The in-boot roof-retraction arrangement of competitor models leaves a greatly reduced amount of space for luggage (up to 93% of the boot’s luggage capacity is sacrificed in the worst case when the roof is stowed) and can force the user to remove luggage from the boot before the roof can be opened. With most models, the user must also get out of the car and manually position a partition board in the boot before starting to open the roof. And since the roof and partition board obstruct the boot opening, they impede the loading and unloading of luggage.
The advantages of the Power Retractable Hard Top mean that a person in the MX-5 Roadster Coupe can open and close the roof quickly and easily, without needing to step out of the car, and without losing luggage capacity. The boot has the same deep, capacious design as that of the soft-top model. It has a capacity of 150 litres (VDA) and can hold bulky items such as a case of a dozen 1.5 litre beverage bottles.
As well as ensuring that the Power Retractable Hard Top has no impact on the boot space, Mazda made it as user-friendly as possible in terms of ease of operation, safety of operation, and look and feel.
Roof-opening and roof-closing operations each take only 12 seconds (the shortest time taken by any electrically retractable hard top on the market today), so the user can open or close the roof without a long interruption in driving enjoyment. But the Power Retractable Hard Top’s operation is not merely fast; a moment of relatively slow movement at the beginning and ending of each roof-opening or roof-closing operation promotes the user’s sense that the operation has been completed reliably and safely.
In pursuit of operation with a natural look and feel, evaluation clinics were conducted with people of various age groups. Compared with other electric-roof-equipped cars, the MX-5 Roadster Coupe scored consistently highly in terms of roof-opening and roof-closing speeds, in terms of the ease with which users can verify completion of roof-opening and roof-closing operations, and in terms of users’ confidence that the roof would neither pinch nor hit them during opening and closing movements.
To give users even greater confidence, the Power Retractable Hard Top has failsafe functions that prevent unintended roof movements while the car is moving. The electronic control unit that governs roof-opening and roof-closing operations provides these functions by interacting with the powertrain control module, keyless entry controller, and other electronic control units and systems and by functioning in accordance with data from sensors located around the car. Reliability also contributes to peace of mind for users. Exhaustive durability tests in diverse temperature conditions helped to ensure ample reliability for frequent operation of the Power Retractable Hard Top.
A wind-in-the-hair open-top motoring experience without much turbulence in the cabin is one of the most popular attributes of the MX-5 soft-top model. To deliver the same experience in the MX-5 Roadster Coupe, the aero board differs from that of the soft-top model because of the different rear deck design.
The front edge of the rear deck (immediately behind the seats) is 40mm higher than that of the soft-top model, so the aero board is supplemented by an air guide that directs forward-flowing air upward so users don’t suffer an uncomfortable flow of air against the back of the neck. Consequently, wind control during open-top driving is every bit as effective as that of the soft-top model.
With the roof closed, exterior noise is effectively kept out of the cabin even during high-speed driving. The superior quietness helps to realize a refined, composed ride befitting a premium model. At the same time, though, the great sports-car engine sound that enhances the enjoyment of the MX-5 driving experience is uncompromised.
The model name differs from market to market. In Europe and Australia, it is ‘Mazda MX-5 Roadster Coupe’. In North America, it is ‘Mazda MX-5 (Miata) Power Retractable Hard Top’. And in Japan, it is ‘Mazda Roadster Power Retractable Hard Top’.
