Thoroughly modern Miller

PUBLISHED : Sunday, 06 August, 1995, 12:00am
UPDATED : Sunday, 06 August, 1995, 12:00am

IF WE accept that the car has been around for nigh on 100 years, then Danish engineer Ralph Miller's 1947 theory of improving on the efficiency of the conventional, internal combustion engine is relatively new technology.

Miller, born in 1890, went to the United States in 1915 and was involved in various areas of engineering, working for a number of employers including Ingersoll-Rand and the American Locomotive Company.

While employed by the Nordberg Manufacturing Company of Milwaukee, Wisconsin, Miller was granted a patent for a device which 'varied the final combustion temperature in four-cycle internal combustion engines'.

But it was not until the early Eighties that Mazda developed Miller's idea of delaying the closure of the intake valve in order to reduce the compression ratio without detracting from the all-important expansion ratio, or power stroke.

By 1990, Mazda's R&D department had sufficiently perfected the so-called Miller-cycle theory and a new, highly efficient 2.3-litre V6 engine was put into production.

It is this engine which powers the top-of-the-range Eunos 800M. Eunos, Mazda's luxury arm, currently comprises three models: the 800, the slightly smaller 500 and the top-selling sports coupe Eunos 30X.

The 800M, with its unique Miller-cycle engine, performs like a three-litre model with, says Mazda, the economy of a two-litre. But technical advances apart, the 800M is a superb car and a casual observer would probably be unaware of any differences under the bonnet.

By virtue of the late valve-closing arrangement, the Eunos engine is able to be equipped with a Lysholm supercharger, which compresses the incoming air-fuel mixture to two atmospheres, without the fear of detonation. As well as producing a healthy power increase, carbon dioxide emissions are also significantly reduced.

Mazda's well-oiled publicity machine has calculated that the CO2 output from the Miller-cycle engine is reduced by as much as 0.6 tonnes per year, based on an average annual mileage of 15,000 kilometres. This, it says, is equivalent to saving about 100 trees in the rain forests.

The unusual engine apart, the 800M is also technologically advanced in other areas, notably its primary safety features. The Eunos features Mazda's computer-controlled tri-synchroniser system, which integrates the four-wheel steering, anti-lock brakes and traction control. Transmission is an advanced four-speed, electronically-controlled automatic.

Secondary safety items include dual SRS air bags, pre-tensioned seat belts and high-tensile steel, side-impact bars within the doors.

The interior of the 800M features full-leather upholstery, while the front seats are electrically adjustable. Entertainment is provided by a superb Bose five-speaker, 215W output stereo system, which includes a CD player and a six-disc autochanger.

Also patented is the hi-reflex, mirror-hard paint finish that is almost impervious to scratches or stone chips.

The Eunos 800M is an unusual car and one which deserves to succeed. It bristles with advanced innovations and yet is a down-to-earth executive sedan. It is competitively priced and slots in just above Mazda's top-selling 929.

Ralph Miller would have been proud of the world's first production car to feature his brilliant invention.