In conjunction with Renault, Nissan Motor has developed two new four-cylinder petrol engines and a new continuously variable transmission (CVT).

The two newly developed engines, the 1.5-litre HR15DE and the 2.0-litre MR20DE, are both in-line units, jointly developed by Nissan and Renault for use in both companies' passenger cars.

The HR15DE engine will first go into Nissan's new Tiida, which goes on sale in Japan this autumn, while the MR20DE engine will first be used in a new minivan scheduled for release later this year. Both engines incorporate a host of new shared technologies and are designed to provide excellent fuel economy combined with improved acceleration under the conditions most commonly encountered in everyday driving.

New technologies claimed to substantially improve fuel economy and torque under ordinary driving conditions include: the combustion period has been shortened and thermal efficiency improved by strengthening gas flow in the combustion chamber; advanced technologies have been employed to reduce friction, including the use of a new machining method for the cylinder bores and the application of a mirror-like finish to the crankshaft and cam bearing surfaces; and the load imposed on the engine to drive the air conditioner and other auxiliary units has been reduced by enhancing their efficiency and improving the control programme.

'Xtronic' CVT

The newly developed CVT is said to further enhance the benefits that characterise this type of transmission, including excellent fuel economy, smooth power delivery without any shift shock and outstanding acceleration performance. In particular, shift response has been improved by tuning the hydraulic and electronic controls. The shift response improvement combined with a wider gear ratio range contributes significantly to the acceleration and fuel economy under ordinary driving conditions.