At one with your car

The chassis of the all-new Mazda MX-5 sports car could easily cope with the demands an engine bigger and more powerful than its 2-litre four-cylinder unit would place on it.

But beefing up its power would have compromised the essence of "Jinba Ittai", the spiritual basis of its being, says MX-5 programme manager Takao Kijima.

It would also have forced engineers to increase the height of the bonnet, in turn affecting pedestrian safety. It would have been more expensive, too.

"No, we never considered anything other than a 2-litre engine," said Kijima.

Jinba Ittai - the synergy of rider and horse moving as one - is the product of Kansei Engineering and is a 30-year-old Japanese process where feel-good factors about a conceptual product find their way into the finished design.

It has been called "sensory engineering" or "emotional usability" and was used in the development of the first-generation MX-5 16 years ago.

Says Kijima of Kansei Engineering: "Emotional values such as 'fun' and 'beauty' are a higher priority than the traditional engineering indices.

"All the senses are involved. Instead of zero-to-100km/h acceleration statistics, Kansei Engineering helps us understand how the car feels through the driver's sense of touch, how it sounds at speed, how it looks with the top folded, and what pleasant scents can be enjoyed during a spring drive."

Kijima says the project team used the Japanese artistic ritual "yabusame" as the symbol of Jinba Ittai - the ceremonial warrior art of shooting arrows at a stationary target from the back of a galloping horse. The custom dates back more than 1000 years.

"Updated to the 21st century, Jinba Ittai is similar to the bond between a Formula One driver and his car. Yabusame stands for the cosy driver-car relationship targeted for the first-generation MX-5.

"In the end, Kansei Engineering is a navigational tool that leads development engineers to study every aspect of design, mechanical function, and dynamic response in order to achieve the highest possible degree of driving satisfaction."

The philosophy extends to the noise the car makes. The distinct sources of noise - engine components, the intake and exhaust systems - were treated like the brass, woodwind and percussion sections of an orchestra, says Mazda. Computers mapped the car's "voice" and settled on a harmony consistent with Jinba Ittai.

Kijima's team identified six categories - driving, braking, cornering, listening, touching, styling - in their search for an all-new oneness between MX-5 car and driver.

The result is a roadster that reinforces the maxim: "The more things change the more they remain the same."

The new car is similar to the original in appearance, performance and spirit, but is marginally bigger all round: 20mm longer, 40mm wider and 20mm taller.

The front track has increased by 75mm and the rear by 55mm. The bodyshell is lighter by about 20kg but modern equipment and safety requirements push the finished product up to 1128kg, about 10kg heavier than the outgoing car. Weight distribution front and rear remains an ideal 50:50.

Mazda says it kept the weight of the car in check by using its "Gram Strategy", where it pruned minute amounts of weight from components. The rear-view mirror, for example, is 84g lighter. The use of more aluminium also helps.

Inside, there is more room for driver and passenger - between 50mm and 70mm in width in each seat - and more rearward seat travel, which especially aids taller drivers. The seats are more supportive, too.

Fit and finish is of a high standard, along with the layout of instruments, which are similar to those from the RX-8.

The 2-litre engine produces 118kW (160bhp) at 6700rpm and 188Nm of torque at 5000rpm. Top speed is around 210km/h and the sprint from zero to 100km/h takes around 7.5 seconds, about a second quicker than the old car.

It is more flexible through the gears than the old unit and benefits from the choice of gearboxes: 6-speed manual or 6-speed automatic with manual-mode paddles on the steering wheel. The automatic will change buyer tastes in most markets.

Briefly, the new MX-5 is an all-round sharper package: it grips, rides and handles better, thanks largely to a considerably stiffer and stronger body, new suspension arrangement - front double wishbones similar to the RX-8, and a new five-link rear setup - and increased wheel travel, which irons out the bumps felt in the old model.

The steering - always an MX-5 strength - is more accurate, too. Nothing fancy about the rack, said Kijima, just an evolutionary tweak here and there.

The MX-5 and its standard 17-inch alloys and run-flat tyres will go on sale here later this year starting at around $45-46,000 for the manual. Expect a $2000 premium for the automatic and about $1500 for leather.

THE SPECS

* Engine: 2-litre four-cylinder producing 118kW (160bhp) and 188Nm of torque * Suspension: Double wishbones in front, five-link setup in rear

* Weight: 1128kg

* Gearbox: 6-speed manual or 6-speed automatic with manual mode

* Price: Around $45-46,000 for the manual