In 1980, Chrysler was facing serious financial trouble at home. Rising fuel prices in America had destroyed Pentastar’s sales, and they didn’t have the money to design more fuel-efficient cars. So, to keep the lights on in Detroit, Chrysler decided to sell its manufacturing operation in Australia.
Since Chrysler Australia had been building and selling Mitsubishi vehicles here for years, it made sense to sell the business to Mitsubishi, which they did. And their top-selling Chrysler Sigma was finally able to wear the name of the company that designed it in the first place.
The first official Mitsubishi-branded Sigma was a face-lifted version of the Chrysler model. Using the same square headlights and deep bumpers found on the JDM Galant, the 1980 Mitsubishi Sigma featured a fully independent suspension, with luxury levels of kit. The base-model flagship Mitsubishi was now just called Sigma, the middle model was called the GL, and the top-spec Sigma was called the SE. Power was supplied by a standard 1.6L, a 2.0L, or a 2.6L ‘Silent Shaft’ 4-cylinder.
For 1981, Mitsubishi released a limited edition performance model called the Peter Wherrett Special. Based on the GLX ‘sport model’, this car featured lowered coil springs, Bilstein shock absorbers, and special 15x6 alloy wheels wrapped in Pirelli P6 tyres; four-wheel disk brakes were fitted for the first time on an Australian-built 4-cylinder car. Power from the 2.6L was also increased to 76 kW, thanks to a special Sonic exhaust system.
Named for the famous automotive journalist, Peter Wherrett, the car was upgraded to his specification, after MMA’s chief engineer challenged him to design a better car. It seemed that Mr. Wherrett didn’t approve of the GH Sigma’s handling, so Mitsubishi invited him to make the car better, and 1016 copies were produced.
Later that same year, Mitsubishi released another performance version of the Sigma, except this one had a lot more power than the Peter Wherrett Special. Called the Mitsubishi Sigma Turbo, this car had a Garrett turbo and 2.0L Astron motor. The result was 116 kW, and Australia’s first home-built turbocharged car.
The redesigned GJ 1982 Mitsubishi Sigma featured a more aerodynamic body, a fresh new interior with round gauges, and improved suspension for better handling. A new top-spec Super Saloon also debuted, and it came standard with two-tone paint, alloy wheels, air-conditioning, and the 2.6L motor.
In 1984, the revised GK Mitsubishi Sigma was released with new front and rear styling. The SE now came with rear disk brakes. The GSR got a new boot lid spoiler, blacked-out trim, and ‘Pepper-pot’ alloy wheels, wrapped in low-profile tyres.
The last-generation GN Mitsubishi Sigma was released in 1985, and it featured a new grille and a more powerful version of the 2.6L dubbed Astron II. The 1.6L was dropped from the range, leaving the 2.0L as the base engine. A new high-roof version of the Mitsubishi Sigma wagon was also introduced. The Sigma was finally replaced in 1987 by the Magna sedan.
The base engine for the Mitsubishi Sigma was the 56kW 1.6L Saturn 4-cylinder. That engine would remain in production until the GN Series was launched in 1985. Next on the options list was the 2.0L 4-cylinder which produced 64kW. It was upgraded to 70kW in the 1982 GJ, and it became the base engine in the 1985 GN.
The top-spec engine was the 2.6L Astron, which made 73 kW. It was updated to produce 83kW in the GN. In the GH Mitsubishi Sigma Peter Wherrett Special, the special exhaust system allowed it to produce 76kW. The GH Mitsubishi Sigma Turbo produced 116kW/235Nm.
The top-spec GH Mitsubishi Sigma SE came with 14-inch alloy wheels and an upgraded interior. The PWS got the aforementioned performance upgrades, along with Recaro seats upholstered in a wool-blend material, an autographed Momo steering wheel, and red paint with a white stripe along the lower edge of the doors.
The Mitsubishi Sigma Turbo got lots of power, two-tone paint, special wheels, bonnet vents, and a unique grille.
In the GJ series, the sporty GSR got alloy wheels, a ‘sport’ steering wheel, four-wheel disk brakes, and unique black body trim. The Mitsubishi Sigma Super Saloon got a more luxurious interior, power windows, power steering, overhead reading lamps, two-tone paint, and additional interior storage compartments.
On the GK Mitsubishi Sigma, all models could now be optioned with electric windows. The SE got new velour seats with lumbar adjustment and a rear armrest with a boot pass-through. There was more chrome trim on all models, and the GSR got new 15-inch alloy wheels. The final GN combined all those features into a simplified model structure.
When it was new, the Mitsubishi Sigma competed against such small executive cars as the Nissan Skyline and Toyota Corona, but it did so with considerably more flair. The sporty Turbo, GSR, and Peter Wherrett Special are still good fun to drive, even by today’s standards.