Run flat tyres (U.S. English: tires) are a modern development, enabling the car to be safely driven even though one of the tyres is punctured. Run flat tyres use rubber rim clips and enhanced sidewalls to support the weight of the car in case of a puncture.
Eco friendly tyres are actually intended to decrease fuel usage, while maintaining the functionality of the vehicle. They possess a low rolling resistance (road friction), and use silica in the tread.