Comparing an old Dunlop SP Sport 9000 to a new Yokohama S.drive

Old tires with plenty of tread can perform poorly or even be dangerous. Time and exposure to elements degrade the rubber and the compound begins to harden. That means that the tire won’t grip as well. This video talks about tire aging and compound degradation.

Aging can also effect the tire structure below the surface. The generally accepted sweet spot of tire life is around 5 years for normal driving. High performance driving and trucks pulling or carrying heavy loads might have a shorter practical life. Some have suggested 4 years.