Reducing weight and improving aerodynamics were key elements in the development of the Mazda 6, according to deputy programme manager Hajima Matsumura.

Fuel economy has been improved by 12% over the outgoing model, he said at the European launch of the new model in France.

"Weight reduction is Mazda's way of engineering - it gives better fuel economy and better driving performance."

Mazda is looking at weight saving across its car lines, he said. The 2 (Demio in Japan) has been launched 100kg lighter than the previous model and the 6 is 35kg lighter.

"Because [it] is bigger and better equipped than the old car, it would have weighed 90kg more if we hadn't taken these weight reduction measures," he said.

Weight saving measures include using up to 7% more high and ultra-high strength steel than on the outgoing model.

The five-door hatchback and saloon boast a drag coefficient of 0.27; for the estate (wagon) the figure is 0.28.

To reach that, engineers went to great lengths, said Matsumura. This included 300 hours of testing to develop a horseshoe-shaped air deflector under the front of the car.

"It was very difficult to get it right while still cooling the brakes," Matsumura said, while passing the part in question around to journalists to examine more closely.

To maintain the 6's legendary quality - it is the only car to complete a German magazine's 100,000km test without a single fault -127 prototypes were built rather than going straight from CAE to production, said Matsumura.

The D-segment-sized 6 goes on sale here in the UK at the end of the year with prices starting at GBP15,100 and a choice of three petrol engines. Diesel models arrive in January and a nine-strong wagon range from February.

New features include an innovative steering wheel control centre which allows the driver to operate everything from the air conditioning and navigation systems to the audio without taking his or her hands off the steering wheel.

Called a cross-functional network or CF-Net, it means there is "20 to 30% less 'look away' time than for a leading German competitor, the one with the control between the front seats," said Mazda Europe product communications manager Manual Bortone.