In hybrids, a portion of fuel savings is derived by automatically turning off the engine while the vehicle is stopped and its engagement again well after the batteries have brought the vehicle up to speed. In Europe this concept is extended even further to regular cars as well. However, in those cars, automatic start-stop systems typically use the conventional starter motor to re-start the engines after a stop. Depending on the driving conditions, this could be quite a strain on the car’s starter. Now Mazda has devised a new system that they claim will provide quicker, more consistent re-starts.
Mazda has developed an idling stop system, called the Smart Idle Stop System (SISS), which improves fuel economy by about ten percent in urban areas where vehicles frequently stop at traffic lights or in heavy traffic during operation. Idling stop systems save fuel by shutting down the engine automatically when the car is stationary, and restarts it when the driver resumes driving. The Mazda system relies on direct injection to function. When the engine is stopped, sensors are used to stop the engine with the pistons in a precise location. This will allow one of the cylinders to have a specific amount of air in the combustion chamber. When the time comes to re-start, fuel is injected directly into the cylinder and ignited. The expansion of the burning fuel is used to get the engine turning to re-start the engine. This all happens in a split second, Mazda claims the engine can re-start in 350 milliseconds, about half the time of a conventional starter. The re-starts are rotated to different cylinders so that the same cylinder isn’t used every time. Mazda claims a 10 percent reduction in fuel consumption during testing in Japan. It would seem logical that if this sort of technology could be adapted by other automakers it might have a huge impact on gas consumption in America. Much of which is wasted with drivers negotiating congested roadways and urban centers. At the very least, Mazda parent company Ford should be able to integrate this into a wider variety of vehicles. Those, like me that are interested in this technology can look towards Mazda plans to introduce this technology to the marketplace in 2009.