2007 Mazda MX-5 PRHT 

Open-Top Fun. Coupe Convenience.

The 2007 Mazda MX-5 Power Retractable Hardtop is a brand-new counterpart to the third-generation MX-5, which was launched in the summer of 2005. It has the same responsive performance and emotive styling as the soft-top model, but is equipped with a unique Power Retractable Hardtop — the first-ever electrically retractable hardtop that doesn’t sacrifice any trunk space.

The MX-5 Power Retractable Hardtop embodies Mazda’s belief that the MX-5 experience should centre on driving enjoyment. And the key to that driving enjoyment is Mazda’s dedication to Jinba Ittai — an intimate driver-car relationship that can be likened to the synergy of a rider and horse moving as one.

" width="193" height="252" border="0" align="right" style="margin-left:10px;"/>The MX-5 Power Retractable Hardtop (PRHT) eclipses other retractable-hard-top cars in terms of design and user-friendliness:

• The MX-5 PRHT is the world’s first electric roof-retraction system that has no impact on trunk space.
Roof operation is easy and quick (12 seconds: the quickest of any electrically retractable hardtop on the market today).
• The MX-5 PRHT has the same great-handling chassis, high-performance powertrain, and throttle-response-enhancing powerplant frame as the soft-top model.
• 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 provide incomparable controllability.
• The suspension system is tuned to accommodate the unique body-stiffness characteristics and other unique attributes of the MX-5 PRHT.
• Reflecting the pursuit of balanced performance, body stiffness is just as high whether the Power Retractable Hardtop is open or closed.
• With the hardtop closed, exterior noise is effectively kept out for a refined, composed ride.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>Whereas electrically retractable hardtops on cars made by other companies use trunk space for roof storage, Mazda’s unique Power Retractable Hardtop leaves the trunk 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-trunk roof-retraction arrangement of other vehicles leaves a greatly reduced amount of space for luggage (up to 93% of the trunk’s luggage capacity is sacrificed in the worst case when the roof is stowed) and can force the user to remove luggage from the trunk 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 trunk before starting to open the roof. And since the roof and partition board obstruct the trunk opening, they impede the loading and unloading of luggage.

The advantages of the Power Retractable Hardtop mean that a person in the MX-5 can open and close the roof quickly and easily, without needing to step out of the car, and without losing luggage capacity. The trunk 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.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/> As well as ensuring that the Power Retractable Hardtop has no impact on the trunk 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 hardtop on the market today), so you can open or close the roof without a long interruption in driving enjoyment.

The Power Retractable Hardtop 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 Hardtop.

" width="193" height="253" border="0" align="right" style="margin-left:10px;"/>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 Power Retractable Hardtop, 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.

Styling that’s Faithful to the Iconic MX-5 Look

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>Staying faithful to the MX-5 identity was central to development of the MX-5 Power Retractable Hardtop’s styling, so the distinctive side silhouette, the low, flowing shoulder line, and other elements of the front and side views are identical to those of the soft-top model.

Toward the rear of the body, essential design adjustments were made to accommodate the Power Retractable Hardtop 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 trunk 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 trunk 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.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>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 Power Retractable Hardtop 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.

A Body Design with Great Looks and Roof Functionality

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>The rear deck cover makes the front edge of the MX-5 Power Retractable Hardtop’s rear deck 40mm higher than the corresponding edge on the soft-top model. For an optimal height balance across the rear deck, the trunk-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.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>The body of the MX-5 Power Retractable Hardtop has exclusive features that emphasize its premium quality and set it apart from the soft-top model. Perhaps most noticeably, the door handles, headlamp trim bezels and front grille trim surround have chrome plating, which adds refinement to sportiness. 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.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>The interior design of the MX-5 Power Retractable Hardtop 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.

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 have storage recesses behind the seats because of the roof storage space between the trim and the trunk.

The seats are the same as those of the soft-top model, so a seatback pocket is provided.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>The Mazda MX-5 soft-top model has outstandingly lively and linear driving dynamics. Therefore, the main goal in the development of the MX-5 Power Retractable Hardtop model was to maintain these driving dynamics and make the driving experience as enjoyable as that offered by the soft-top model:

• The MX-5 Power Retractable Hardtop has the same great-handling chassis,high-performance powertrain, and throttle-response-enhancing powerplant frame as the third-generation soft-top model.
• 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 provide incomparable controllability.
• The suspension system is tuned to accommodate the unique body-stiffness characteristics and other unique attributes of the MX-5 Power Retractable Hardtop.
• Reflecting the pursuit of balanced performance, body stiffness is just as high whether the Power Retractable Hardtop is open or closed.
• A refined and composed road feel reflects the MX-5 Power Retractable Hardtop’s premium quality.

Great Handling and a Great Sound

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>The MX-5 Power Retractable Hardtop 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 Power Retractable Hardtop’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 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 Power Retractable Hardtop’s movements feel slightly gentler than those of the soft-top model; drivers and passengers perceive a relatively smoother, milder road feel.

To make the driving experience even more enjoyable, the great handling is accompanied by an exhilarating engine sound courtesy of the same Mazda engines used in the soft-top model.

Response and Expansion Feel

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>A light, compact, highly responsive, powerful engine with appropriately sporty intake and exhaust notes was developed to assure that the Mazda MX-5 is brisk, nimble, linear in response, and very fun to drive.

Based on the acclaimed MZR engine series installed in other Mazda models, the MX-5 engine is front-midship mounted and adopts the latest technologies developed to boost power appropriately for a lightweight sports car while supporting environmental compatibility with greater fuel-economy and reduced emissions.

The Mazda MX-5 engine focuses on “response” and “expansion feel.” A lighter flywheel, a quick response, an electric throttle and a stiff drive shaft all helped realize the responsive direct feel of the Mazda MX-5.

The engine’s torque curve is held nearly level at high rpm by major reductions in intake and exhaust restriction. The result is an engine champing at the bit as it revs enthusiastically past the point of maximum torque to the redline, with superior response and direct feel.

In tuning the Mazda MX-5’s engine sound, a smooth, harmonic note was realized that increases with throttle opening. Above 5,000 rpm, this becomes powerfully resonant, consistent with the spirited charge for the 6,700 rpm redline. A throaty 500 Hz sound through the mid-range reinforces the Mazda MX-5’s feeling of nimble responsiveness.

Optimal Weight and Body Dimensions

The MX-5 Power Retractable Hardtop is only 36kg heavier than the third-generation soft-top model. Although adopting the Power Retractable Hardtop 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 Power Retractable Hardtop 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 combination of lightness and compactness contributes to lively, linear performance that’s manifested in the form of satisfyingly brisk response to the accelerator pedal. And since the roof — a relatively heavy item — retracts within the wheelbase, it does not detract from the weight distribution and yaw-inertia moment that help to make the third-generation MX-5 handle so well.

Uncompromised Body Stiffness

The body opening used to accommodate the retracted roof is bigger than the corresponding opening in the third-generation 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 five-speed manual transmission is carried over from the second-generation MX-5 with key changes. To handle the additional torque, the inner structure of the transmission, the counter shaft, and third gear are stronger. Triple-cone synchronizers for first and second gears, double-cone synchros for third, and a carbon-type synchro for fourth reduce shift effort.

Gear ratios in the six-speed manual transmission are purposely close to enhance the joy of sporty driving. Short, quick shift strokes have been achieved by use of triple-cone synchros on the first four gears. To reduce inertia, the third-fourth synchro is located on the counter shaft. For positive feel, the shift linkage is a single unit supported by low-friction bushings and guided by a steel plate.

As a convenience, reverse is located adjacent to first gear. Accidental engagement is prevented by the need to press down on the shift lever in order to select reverse gear.

An optional Sport mode automatic transmission adds a fresh dimension to the MX-5’s driving personality. Six ratios are provided with wide spacing in the interests of fuel efficiency. First gear is 31-percent lower than the second-generation MX-5 automatic to provide a very aggressive launch performance. Sixth gear is 21- percent higher for high mileage and quiet highway cruising. Steering wheel paddle shifters are available on the GT model. Paddles mounted behind the steering wheel command upshifts while buttons positioned on the spokes are used for downshifts. Coordinating engine torque with the shift sequence results in smooth, seamless, and fast gear changes.

" width="161" height="254" border="0" align="right" style="margin-left:10px;"/>The Mazda MX-5’s double wishbone front suspension and multi-link rear suspension system with optimized geometry help extract the best the tires have to offer.

Aluminum was used for some chassis parts to minimize unsprung weight. Attaching the rear cross member directly to the unibody with no rubber isolation enhances chassis rigidity while reinforcing the feeling of oneness. Careful tuning of the rack-and-pinion power steering gear yields low friction, high linearity, and delightfully smooth steering response.

The rear suspension is engineered to enhance dynamic stability by optimizing the positioning of the tires on the road. To curb unwanted steering, pitch motion of the body during acceleration and braking is tightly controlled by the dampers and by anti-dive, anti-squat geometry.

" width="193" height="254" border="0" align="right" style="margin-left:10px;"/>Configuring the braking system for short pedal travel, response tied directly to pedal force, and a high degree of linearity is also a means of enhancing the Mazda MX-5’s feeling of oneness.

Front rotors are 20 mm (0.8 inches) larger in diameter for improved thermal capacity and callipers are 25 percent stiffer. Brake hoses are less resilient and the power booster is 25.4 mm (1 inch) larger than before. Thanks to these revisions and improved front-to-rear balance, stopping distances achieved with the four-wheel single-piston-calliper disc system are exemplary.

Safety and environmental compatibility match those of the soft-top model

• High visibility, controllability, and braking performance enhance the driver’s ability to see and avoid hazards.
• A high-crashworthiness body made with a high proportion of high-tensile steel is complemented, among other safety features, by an airbag system developed specially for the MX-5 to promote occupant protection (airbag system available on GT models only).
• Advanced security systems provide peace of mind.
• Fuel-efficient, low-emission engines, high recyclability, and minimal use of substances that place a burden on the environment address users’ environmental concerns.