The challenge with a petrol or diesel engine is to get the most energy out of every drop of fuel. If you use less fuel, you produce fewer emissions and help protect air quality. There are fundamental things you can do with an engine to achieve this. You can make the combustion process more efficient, so less fuel is wasted. You can also reduce the engine’s weight and cut the amount of energy lost through friction between its working parts. To make our engines lighter we have introduced new lightweight materials, including resins and plastics, and have combined individual components to single units that weigh less and take up less space. To reduce friction we have produced special coatings for internal components and developed new lubricants for smoother running.
The hybrid petrol engine in the 2016 Prius demonstrates just what we can achieve – it is the most thermally efficient petrol engine in the world, which means less energy is being lost as heat inside the engine and more is available to drive the wheels. Although this engine is part of a hybrid system, we are seeing similar gains being made in our new generation of conventional engines, including the 1.2 and 1.0-litre units we use in our Yaris and Aygo models.
We are achieving better control of the amount of fuel used with more precise fuel injection systems, intelligent valve timing and improved design of the engine combustion chamber. Our new generation petrol engines are also able to run on different operating cycles to suit different driving conditions – for example when you start up and when you are driving on the open road – applying know-how from our hybrid programme.
It isn’t just under the hood that fuel savings can be made. We combine our engine technology with aerodynamic designs that help our cars move smoothly through the air, reducing the drag effect and bringing down fuel consumption.