When it comes to cars, lightening the load can increase performance capabilities and fuel economy. Incorporating plastic components into the body of the car can only cut down the weight so much. So, auto makers are scrambling to find ways to use plastic parts in other components of the car. German research group Fraunhofer has found a way to create a car engine using plastic parts. Sure the pistons need to be metal, but the casing that houses the cylinders can be made of plastic. Fraunhofer's plastic casing weighs 20% less than if it were made using standard aluminum, and a little goes a long way when it comes to performance and saving fuel.