1972-1977 Mazda RX-4 / Luce Rotary

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Production Period: 1972-1977

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In late 1972 the RX-4 second generation rotary-powered Mazda Luce vehicle arrived, but this time in RWD guise and powered by the bigger 12A engines that had become standard Mazda rotary fare. The heavier RX-4 was marketed as a luxury/sport-type vehicle and subsequently was produced in three basic body styles - the hard top, the sedan and the custom. The RX-4 also appeared in smaller numbers in Luce Wagon and Grand Turismo forms - the latter featuring US-style woodgrain panels on the sides of the car.


1972 was a big year for Mazda and its rotary engine. Mazda was riding high on its wave of international success while other manufacturers such as GM, Nissan and Citroen showed envy by spending big on their own rotary research and development.

Mazda released the Series 1 RX-4 (named the Luce in Japan) in October '72. The new arrival marked the sixth rotary powered car in as many years. This RX-4's marketing theme was 'low pollution' and 'luxury' and with the USA and Japan tightening emission laws, the RX-4 AP (anti pollution) was the world's first production car to pass the choking 1975 emission standards for both countries (equivalent to mid 80s Aus. standards.).

The Luce/RX-4 came in three body styles: sedan, coupe and wagon.

The RX-4 was released to the Australian public in April 1973. Like the RX-3, Australia missed out on the wagon. The sedan and coupe versions, the 'Deluxe' and 'Super Deluxe', were roughly based on the middle range Japanese GR and GS specs: vinyl trimmed seats, AM radio, manual steering and 4-speed manual gearbox. For the Series I, the auto was only available in the Sedan. Mazda's marketing was insightful and delivered the up-spec 130 bhp twin dizzy 12A.

The Series I RX-4 sedan has a flat nose and a (lower spec) flatter dash when compared to the coupe's pointed nose and cockpit styled dash. The cockpit dash was more in line with the up-spec Japanese model and demonstrated a more personalized interior. Mazda learnt from the RX-3/808 how expensive it was to separate models with different parts so most changes were only cosmetic inside and out.

Wheels and tires were 13x5.5-inch with 175-70 radials, the widest wheels of the RX cars to date. However some countries were blessed with even wider 195-70x13 tyres. Acceleration was considered reasonable at the time with the manual sedan turning a 17.4 ET and the auto not far behind at 17.9. The Series I sedan was priced $3938 and the coupe at $4168 (AUD).

Mazda's best year for the rotary was 1973. Production was in full swing and by the year's end it had exceeded the 600,000th rotary vehicle, a major milestone for the small Japanese manufacturer. Three new engines were developed including the 13B, the 15A and the monster 21A. However the late 1973 Arab oil crisis shocked the industry so badly that Mazda (and many other manufacturers) canned future development.

Fortunately for the RX-4, the 13B was slated for the Series 2 which debuted in Japan in Dec '73. The big news was the new top-shelf GT sedan and coupe.

With the upspec single dizzy 12A now reduced to 125hp, the 13B's horsepower increase to 135hp and torque increase to 132lb-ft gave the heavy RX-4 enough grunt to beat all but the best on Japanese roads. A factory quoted 15.8 ET with a top speed of 195 kph gave the Luce GT (RX-4 13B) a fearful reputation. Handling was improved with torque rods used to laterally locate the live rear axle which gave extra stability through corners as did wide 195-70x13 radials on 5.5 inch steel wheels (or the optional four-spoke alloy wheels). The Series 2 hit Australia in April '74. Notably the 13B was standard along with the four-speed manual. The box was totally reworked to handle the 13B's extra power. An additional bonus was the auto making its way into the coupe's option list. The sedan's flat nose was changed for a pointed nose and the dashboard changes followed. In fact the only external differences between the series 1 and 2 coupe can be found with the change from the RE12 to the 'Rotary Engine' badges and the REAPS rear muffler with exhaust cutout in the lower beaver panel.

The oil crisis all but killed the RX-4 in Europe and the U.S. Taking a big financial nose dive, Mazda's financing bank appointed its own men to Mazda's board of directors to help steer the company away from bankruptcy. The public sees the legacy of this in the time span between the introduction of the RX-4 in '72 to the RX-5 in '75. Low pollution was no longer a priority. Better fuel consumption was.

For the period of May 1975 to April 1976, Mazda Motors Pty Ltd (which covered Victoria, Tasmania and southern NSW) sold only 999 rotary vehicles (including the RX-2, 3 and 4). By 1976, pricing for the Series 2 sedan had crept up to $5014 and the coupe to $5195. Still very reasonable considering its competition like the 160-hp 6-cylinder Chrysler Centura GL for $5162, the 155-hp 6-cylinder Ford Cortina XLE for $5753 and the 135-hp 6-cylinder Datsun 240K at $5156 which were all heavier and less equipped.

Mazda released the Series 3 RX-4 in April '76 with some major exterior and minor interior changes. The nose was flatter with a completely redesigned grille, enhanced with a lower spoiler and the rear now had a flat plastic panel with recessed taillights. The interior received a new steering wheel (also RX-5) and minor console alterations. The 195-70 tires became an option but notably a new MacPherson strut front suspension and revised settings gave favorable improvements. The 13B didn't officially lose its 130 bhp but it did drop its fuel consumption rate even with a 280 lb weight increase (to 2580lb or 1170kg) over the Series I plus a price hike to boot. Performance was still quite adequate with the sedan holding down low 17 second ETs.

Mazda had installed its lowest diff ratio yet, 3.636:1 compared to Series I's 3.9:1. Mazda Motors quotes selling 436 rotary vehicles between May '76 and March '77. Figures were very similar for the other state distributors. Due to these slow sales the decision was made to remove the coupe from Australian sales at the beginning of '77. By this time the sedan was priced at $6382 - still comparable with its competitors. The sedan lasted through June '79. By this time the RX-7 had been on sale for a number of months and the RX-4, with out-of-date styling, was crowding showrooms. Although the Series 3 sold here for over three years, sales would have been luck to reach 30 percent of the Series 2.

Racing wise, the RX-4 has almost no history to speak of. A vain Bathurst attempt (against quicker 12A powered RX-3s) proved unsuccessful but overseas rallies showed the RX-4 could finish on the podium.

Looking for a genuine RX-4 shouldn't be too hard. The Series 1 ID starts with LA22S (for the 12A) with the series 2 and 3 with LA23S (for the 13B). The Series 1 to 3 929 will be LA2VS. As mentioned the RX-4 wagon was never officially sold here but there are a few special imports about - LA22W or LA23W signifies RX where LA2VV is piston powered.

The RX-4 fuel tank will be larger than the 929 - 65 litres compared to 45. All RX-4s and 929 coupes scored a tacho, but the 929 sedans missed out - a 6500rpm redline identifies a rotary. The Series 2 and 3 (13B) axles and diff are larger and stronger than the Series 1 and 929. The Series 1 design means a better diff ratio can be sourced from only a 1977-79 Mazda E1600 van with 4.4 diff. All up the RX-4 was produced for seven years from October 1972 to June 1979.

Years Available: 1973 to 1979 Engine: 12A (1146cc) twin rotor (2 x 573cc) Carby and 13B (1308cc) twin rotor (2 x 654cc) Carby Transmission: 4 Speed Manual and optional 3 Speed Auto Power (Approx.): 125hp (93kw) (12A), 135hp (101kw) (13B) Torque (Approx.): 117 Lb/Ft (158Nm) (12A), 132 Lb/Ft (179Nm) (13B) Weight (Approx.): 1050 kg (Coupe) 1045 kg (Sedan) rising to 1170kg (Series 2) Chassis Prefix: LA22S (Series 1 12A models) and LA23S (Series 2 & 3 13B models) Specification: Deluxe and Super Deluxe Sedans and Coupes Original Cost (Approx): $3938 AUD for Sedan and $4168 AUD for Coupe (Series 1 prices) rising to $5014 AUD for Sedan and $5195 AUD for the Coupe (Series 2 prices) in 1976 and $6382 AUD for the Sedan (Series 3) in 1977

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