Mazda Roadpacer Anti-Pollution

Today's car was written by Scott Brown, who totally beat me to the punch writing about the Mazda Roadpacer. I strongly considered it for Mazda Week a while back, but thought it a little too…lame I suppose! He does it justice–even if it's probably the reason General Motors never made that rotary Corvette…

Enjoy! -M!

GM Holden have long been positioned as "Australia's car maker.” For decades they've been building big cars with 6 and 8 cylinder engines for Australian families, a perfect match for the country's large and sparsely-populated land mass. 

It's a formula that has started to shift in recent years: with Australians moving to more efficient cars and SUVs instead of big sedans, the current Holden Commodore and Ford Falcon local heroes aren't long for this world.

Over the years, there have been a number of deviations from this formula, some in an attempt to cut fuel costs (like 4-cylinder engines), and some intended to re-image the locally-built cars or expand to new markets (just Google Holden Adventra).

Of course, some of these experiments are just plain weird. This is the story of one of the weirder deviations: the Mazda Roadpacer AP, or Anti-Pollution.

The story goes that Chevrolet were experimenting with a mid-engined Corvette (a constant source of rumors even to this day), as well as the feasibility of fitting it with a Wankel "rotary" engine. They consulted Mazda for advice (because who else would you ask about rotaries?) and somehow struck a deal to trade some cars for their knowledge. Mazda at the time needed a large car for the Japanese market to compete with the large cars of Mitsubishi, Toyota and Nissan, so the car chosen as a base was the HJ Holden Premier.

The Holden HJ built from 1974 through to 1976 was the typical Australian car. It was full-size and sold as a sedan, wagon, ute, coupe or panel van, with choice of a handful of 6 and 8-cylinder engines.

The Premier was the cream of the crop with some extra equipment, quad headlights and some other styling touches such as extra chrome. The car sold well with more than 176,000 HJs produced, and can still be seen trundling around the Australian countryside doing what they were born to do.

So far this doesn't sound too bad—perhaps if Mazda had elected to sell those Holdens as-is I wouldn't be writing this piece. But that's not what happened. In order to take advantage of tax breaks given to smaller-engined cars, Mazda chose to replace the torquey 3.3 litre straight-six engine of the Premier with a 13B rotary engine. 

And therein lies the problem. 

For all their strengths, rotary engines aren't known for their torque, something that's required when you're hauling 1575kg (3472 lbs) of Aussie-built steel. The 13B was capable of 187nm (140 lb-ft) of torque, while the Holden Red Straight-Six they replaced could do 263nm (194 lb-ft). 

What's more, the 13B's maximum torque was delivered at 6000 rpm while the Holden's was just 2000 rpm. This shortcoming was exacerbated further by only offering the car with a 3-speed automatic transmission, not the best choice for extracting torque when it arrives so late in the rev-range.

Predictably, though, the rotary was smooth once it got going…but also offered woeful driving performance and bad fuel economy (another common problem with rotary engines). Reports suggest it used as much as 26 litres per 100km, considerably worse than even the 5.0-litre V8 offered in the HJ Monaro. 

So much for calling it the “Anti Pollution.”

In keeping with the car's upper-luxury intent Mazda did add some other goodies to tempt buyers including central locking which activated at 10km/hr, a sound chime at 90km/hr, stereo controls front and back and a voice dictation system. It was also given fender mounted mirrors, a common feature of Japanese cars at the time, and cool "Roadpacer" badging. 

All this contributed to a hefty price tag of 3.8 million yen. Offered only in Japan for two years, just 800 were sold. Many of these went to government officials who got rid of them as soon as possible—and few remain today. Scouring the Internet, it seems Mazda have one on display in a museum somewhere, and at least one has been imported to New Zealand.

It was the first and last General Motors vehicle produced with a rotary engine, and the first and last time a vehicle has been given the nickname, “Toadpacer.”



Mazda Roadpacer AP:,,,


HJ Holden: (1, 2),