Mazda MX-5


Mazda MX-5

The Mazda MX-5 is a popular sports car built by Mazda in Hiroshima, Japan, since 1989. It is known as MX-5 Miata (or popularly just Miata) in North America, MX-5 in Oceania and Europe, and Roadster (under the Eunos marque until 1996) in Japan. The MX-5 is one of the world’s best-selling sports cars, with 748,904 cars sold until the end of 2005. Beginning with the third-generation 2006 model, Mazda consolidated worldwide (excluding Japan) marketing using the MX-5 name, though enthusiasts in the USA (and the company itself) still refer to it as Miata, a name that means “reward” in Old High German.

The return of the sports roadster

The MX-5 was envisioned by its designers as a small roadster with a minimum of unnecessary weight and complexity, a direct descendant of the small British roadsters of the 1960s such as the Triumph Spitfire, MG Midget, Lotus Elan, and Porsche 550 Spider. By the early 1980s, roadsters had all but vanished from the market, sacrificed to the increasing safety and anti-pollution regulations everywhere. The MX-5 would thus mark the return of the roadster, using modern technology allied to the tradition of the roadster type.

As a result, the MX-5 has a traditional FR (front-engine, rear-wheel-drive) layout and 4-wheel independent double wishbone suspension. It comes with a longitudinally mounted four cylinder engine coupled to a manual transmission (an automatic transmission is available as an option).

The body is a conventional, but very light, unibody shell. The MX-5 also incorporates a unique trusswork called the Powerplant Frame (PPF) which connects the engine to the differential, minimizing flex and creating a tight, responsive feel. Many MX-5s feature limited slip differentials and antilock brakes. Traction control is an option available on some models.

Mazda MX-5 (1989)
1989 Mazda MX-5
With an approximate 50:50 front/rear weight balance, the car has very neutral handling, which makes it easy to drive for the beginner, and fun for the advanced driver. Inducing oversteer is easy and very controllable. The MX-5 is thus popular in amateur and stock racing events, including, in the USA, the Sports Car Club of America’s Solo2 autocross and Spec Miata race series.

As a measure for success, the Guinness Book of Records declared the MX-5 Miata the world’s best-selling sports car on February 13, 2002, with more than 700,000 sold until that date.

The MX-5 has won over 150 awards in its history, including making Car and Driver magazine’s annual Ten Best list seven times; Wheels Magazine ‘s Car of the Year for 1989 and 2005; Sports Car International’s “best sports car of the 1990s” and “ten best sports cars of all time”; 2005-2006 Car of the Year Japan; and 2005 Australian Car of the Year.

There have been three generations of the MX-5, each introducing overall changes to the exterior, interior and mechanical components of the car: the first generation, with production code NA, was produced from 1990 to 1997 in model years; the second generation, NB, from 1999 to 2005; and the current third generation, NC, from 2006.

The competition to design the MX-5

The design of the first MX-5 was the result of an internal Mazda competition between the two Design Studios in California, USA and Tokyo, Japan. The role of designing an FR (front-engine, rear-wheel drive) light-weight sports car was assigned to the California Design Studio whilst at Tokyo two different models were entered the competition: an FF layout (front-engined, front-wheel drive) and an MR layout (mid-engined, rear-wheel drive).

The first round of judging the competing designs for the MX-5 was held in April 1984. Designs were presented on paper. The mid-engined car appeared the most impressive, although it was known at the time that such a layout would struggle to meet the noise, vibration and harshness (NVH) requirements of the project. It was only at the second round of the competition in August 1984, when full-scale clay models were presented, that the California FR design, codenamed “Duo 101”, won the competition and was selected as the basis for Mazda’s new light-weight sports car.

The Duo 101 design, so named as either a soft-top or hard-top could be used, incorporated many key stylistic cues inspired by the Lotus Elan, a 1960s roadster widely considered as one of the best-handling sports cars of its day. International Automotive Design (IAD) in Worthing, England was commissioned to develop a running prototype. It was built with a fiberglass body, a 1.4-liter engine from a Mazda Familia and components from a variety of early Mazda models. The prototype was completed in August 1985.

After some minor changes in the design, the project received final approval on January 18, 1986 and the car was now codenamed P729. The task of constructing five engineering mules (more developed prototypes) was again allocated to IAD, which also conducted the first front and rear crash tests on the P729. The project was moved to Japan for final engineering details and production issues to be decided. The MX-5 was almost ready to be introduced to the world as a a true light-weight sports car, weighing just 940 kg (2070 lb).

First Generation (NA)

The MX-5 was unveiled at the Chicago Auto Show on February 10, 1989, with a price tag of US $13,800 (US $22,650 in 2006 adjusted for inflation). The MX-5, with production code NA, would be available for delivery to buyers on July 1989 as a 1990 model. An optional hardtop was made available at the same time, in reinforced engineering plastic.

In Japan, the car was not badged as a Mazda, as the company was experimenting with the creation of different marques for deluxe models, similar to Nissan’s Infiniti and Toyota’s Lexus. Instead, the Mazda MX-5 was sold as the Eunos Roadster in that market.

The body shell of the NA was all-steel with a light-weight aluminium hood. Overall dimensions were 3970 mm (156.3 in) in length, 1675 mm (65.9 in) in width, and 1235 mm (48.6 in) in height. Drag coefficient was indicated as 0.38, reasonably aerodynamic. Suspension was an independent double wishbone on all four wheels, with an anti-roll bar at the front. Four wheel-disc brakes, ventilated at the front, were behind alloy wheels with 185/60HR14 radial tires.

The original MX-5 came with a 1.6-liter double overhead cam inline four-cylinder engine, producing 90 kW (120 hp) and 100 ft·lbf (136 N·m) of torque. The engine employs an L-Jetronic fuel injection system and a camshaft angle sensor instead of a distributor. This engine, codename B6, had been previously used in the 323 series, including the 323 GTX, a turbocharged, all-wheel drive vehicle, and retained the reinforcements and under-piston oil sprays required for aftermarket turbocharging.

Standard transmission was 5-speed manual. Japan and the USA got an optional automatic transmission which proved unpopular; these markets also received an optional viscous limited slip rear differential.

The NA could reach 96 km/h (60 mph) in 9.4 s and had a top speed of 190 km/h (119 mph).

For the 1994 model year, the first-generation MX-5 was freshened with the introduction of the more powerful 1.8-liter BP engine, dual airbags and a geared, torque-sensing limited slip differential in some markets. The chassis was substantially braced to meet new side-impact standards, most obviously by adding a bar between the seatbelt towers inside the car, but also to the front and rear subframes. No exterior changes were made, though. This is called the NA Generation 1.5.

The new engine produced 98 kW (130 hp), increased to 133 hp (99 kW) from 1995. The base weight increased to 990 kg (2180 lb). Performance was improved slightly, the additional power being partly offset by the extra weight. In some markets such as Europe, the 1.6 engine continued to be available as a lower-cost option, but was detuned to 88 hp (66 kW). This lower-powered model did not receive all the additional chassis bracing of the new 1.8. Japanese and US cars were fitted with an optional Torsen LSD, which was far more durable than the previous viscous differential.

There were a number of trim levels and special editions available, determined by local Mazda marketing departments. In the US, the base model was called the “A Package”. A “B Package” added some options, while the “C Package” included a tan interior and top and leather seats. The “R Package” was for racing, and the annual special editions were formalized as “M Editions” from Generation 1.5. These included all of the luxury options from the “C Package” as well as special paint and, sometimes, special wheels.

The first generation MX-5 was phased out with the 1997 model year (there was no 1998 model year), with the final 1500 NAs produced for the US market being the “STO” (“Special Touring Option”) versions.

Second Generation (NB)

In 1998, Mazda released the second-generation MX-5, production code NB, for the 1999 model year. The NB featured a more powerful engine and, on the exterior, more modern styling cues borrowed from the 1992 Mazda RX-7 model. Prices in the United States, the main market for the MX-5, started at US $19,770 (US $24,680 in 2006).

Although many parts of the interior and body were different, the most notable changes were the headlights: the first generation’s retractable headlights had been exchanged for fixed ones. The new car had grown slightly in width compared to the earlier model with dimensions: length 3955 mm (155.7 in); width 1680 mm (66.1 in); height 1235 mm (48.6 in) and wheelbase 2265 mm (89.2 in). Without options, the NB weighed exactly 1000 kg (2205 lb). The new generation was slightly more aerodynamic than the original, with a Cd figure of 0.36.

The NB continued to employ four-wheel independent suspension, with enlarged anti-roll bars at the front and rear, but the wheels, tires and brakes were significantly upgraded: ABS was offered as an option; alloy wheels were now 14 in or 15 in in diameter and 6 in in width, depending on the trim package; sports models were equipped with the larger wheels and 195/50VR15 tires.

The BP-4W engine remained at 1.8 L but received several minor updates. The engine compression ratio was raised from 9.0:1 to 9.5:1 by adding slightly domed pistons. The intake cam was changed to a solid lifter design with a stronger cam. The intake runners in the head were straightened and the intake manifold was mounted higher up. Mazda’s Variable Intake Control System system was introduced, which effectively gave a long narrow intake mainfold at low rpm for better swirl, changing to a short, free-flowing manifold at high rpm for maximum breathing. Power output of the new engine was quoted at 105 kW (140 hp) with 119 ft·lbf (161 N·m) of torque.

The 1.6 B6 engine remained available in some markets, including Europe and Japan.

The 1.8 NB could reach 96 km/h (60 mph) in 7.9 s and had a top speed of 197 km/h (123 mph).

In 1999, Mazda celebrated the 10th anniversary of the MX-5 with the 10th Anniversary Model, a limited edition featuring some until-then exclusive features, namely a six-speed transmission and Bilstein shock absorbers,; performance figures were slightly different, with faster acceleration but lower top speed than the standard 1.8 NB.

For the 2001 model year, a facelift to the Second-Generation MX-5 was released. There were some minor exterior changes, with a press-release of July 18, 2000 announcing the changes as “resulting in an even sportier and more forceful look”. Thus Generation 2.5 was born. Some cockpit elements were also changed, with instrument panel gauges having a white face and red numbers. The seats were also upgraded, incorporating more support in the side bolsters, and taller headrests. Added for top models were 16-inch wheels with 205/45VR16 low-profile tires and larger brakes at the front and rear. The upgraded tires and suspension allowed the new model to pull 0.88 g in lateral grip in tests by Car and Driver magazine. The body was strengthened, gaining 16% in bending rigidity and 22% in torsional rigidity. With the minimum of options, the 2001 model weighed 1065 kg (2350 lb).

The 1.8 BP-Z3 engine was slightly modified and now featured variable valve timing on the intake camshaft. The intake and exhaust system also received a minor upgrade. These modifications resulted in a power output of 117 kW (155 hp) (Japan and Australia) or 110 kW (146 hp) (US and Europe). In the United States, Mazda erroneously quoted the power figure for the Japanese and Australian model in early catalogues. Car and Driver magazine and numerous owners confirmed the missing power, and Mazda was forced to offer to buy back the 2001 cars due to those misleading power claims. Owners who did not take up the buy back offer were offered an apology and free servicing for the warranty period.

In 2001, Mazda Australia produced locally a limited run of 100 turbocharged MX-5s labelled the SP. Over 215 parts went into upgrading the performance of the SP creating a powerful sportscar that looked identical to a standard MX-5. The driveline, braking, suspension and engine internals remained standard. The upgraded engine was rated at 157 kW (201 hp).

The 2004 model year saw the introduction of the official turbocharged Mazdaspeed MX-5, Roadster Turbo in Japan. It featured a light-pressure turbo BPT engine for 178 hp (133 kW). Other features included a special suspension, upgraded transmission and clutch assemblies, upgraded drivetrain components, Racing Hart 17-inch wheels, special interior trim, and special exterior paint. 5,428 Mazdaspeed MX-5s were produced during model years 2004 and 2005.

Still in the 2004 model year, a division of Mazda in Japan produced a limited run of 350 Roadster Coupés with an integral hardtop roof, effectively making this a coupé instead of a roadster. The body structure was reworked to incorporate the roof for a substantial increase in chassis rigidity and a weight increase of 10 kg (22 lb). No Roadster Coupes were exported outside Japan.

Third Generation (NC)

Production of the third-generation MX-5, code NC, began May 17, 2005, for delivery in August, for the 2006 model year.

Despite the success in maintaining enough external similarities, the third generation shares no components with the second generation, except for the side-panel turning-lights on the European-spec models. It can thus be considered an all-new MX-5. The suspension was changed from a 4-wheel double wishbone setup to a front wishbone/rear multilink setup. Technologies like traction control and stability control were added to increase driveability.

The exterior styling harkens back to the original design while adopting a clean, more muscular profile. Some design elements were adopted to reinforce the family ties with the Mazda RX-8. Unlike the update from NA to NB, which was mostly a nose/tail/interior change, there are substantial differences in every body panel of the NC, so much that older-generation accessories will not work on the NC.

For Australia and the USA, the engine was the new 16-valve, 2.0-liter MZR I4, producing 170 hp (128 kW) and 140 ft·lbf (190 N·m), coupled to a 6-speed manual transmission. For Europe, two engines are offered: the same 2.0 MZR, but producing 160 hp (118 kW) and 188 N·m; and a new 1.8 MZR, producing 126 hp (93 kW) and 167 N·m, coupled to a 5-speed manual transmission.

A 6-speed automatic transmission, with steering wheel mounted paddle shifters, is optional. A test by Car and Driver magazine revealed a 0-97 km/h (0-60 mph) time of 6.5 s for the 2.0 NC.

The NC was launched with a special edition called “3rd Generation Limited” which featured added chrome accents and special wheels. 3500 were built worldwide (300 in the UK, 750 in the USA), delivered in advance of standard models.

On 18 July 2006, Mazda unveiled a coupé convertible version of the NC with a three-piece folding hardtop. The British International Motor Show was the venue chosen for the world premiere of the new model, named MX-5 Roadster Coupe in Europe, Roadster Power Retractable Hard Top in Japan, and MX-5 Miata Power Retractable Hard Top in the USA.

Adding 37 kg (82 lb) to the weight of a comparable model with soft top, the hard top takes 12 seconds to raise or lower; in a departure from the competition, it does not take any of the existing trunk space when folded down. The price premium is expected to be less than the cost of a separate hard top.

Production numbers

The 250,000th MX-5 rolled out of the factory on November 9, 1992; the 500,000th, on February 8, 1999; the 750,000th, on March 2004.


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