When the new Opel Astra arrives next month, it will have the marqué’s latest “Twinport” engine technology, said to provide improved engine efficiency.

When the new Opel Astra arrives next month, it will have the marqué’s latest “Twinport” engine technology, said to provide improved engine efficiency.

Using variable valve timing and a high proportion of exhaust gas recirculation, a six per cent fuel saving was achieved over the previous ECOTEC engines. Adaptations to the powertrain achieved a further one per cent reduction in fuel consumption.

With the system, the ECOTEC 1,6-litre engine receives up to 25 per cent of its cylinder charge from previously burnt exhaust gas routed through a link to the exhaust manifold. With this, induction losses under part load are greatly reduced as less work is required from the engine to charge the cylinders on the intake stroke.

Each cylinder has two intake ports and under part load, a flap valve closes one of the two ports. This ensures a high level of combustion chamber swirl and efficient mixing of the fuel/air mixture for complete combustion.

Along with the updated technology, further changes have been made to the 1,6-litre ECOTEC engine’s design. The engine block has been redesigned in terms of weight and vibration and the valve gear is now smoother. Items like the water pump have been relocated for easier engine assembly while the overall quality has apparently also been increased.

The new engine will make its first appearance in South Africa in October when Opel’s new Astra is launched here. Initially, five petrol and three turbo-diesel engines were offered in Europe. While the 1,4-litre derivative is unlikely to make it to SA, the range will probably feature the 1,6-, 1,8- and 2,0-litre petrol derivatives. The turbodiesel and turbo-charged petrol models can be expected at a later date.