25 years of tires

Tires have changed remarkably in the last 25 years.  Still round and still black that is about the only thing that hasn’t changed in tire technology.  In 1986 Z, W and Y speed ratings did not exist.  V rated tires were reserved for the ultimate sports cars.  Tire and Rim Association’s industry standards yearbook recognized only 65 passenger car tire sizes and there were no sizes over 17 inches or higher.  By 2011 Tire and Rim recognized 330 total passenger car sizes with dozens of styles over 17 inches.  According to Michelin spokesman Sachin Despande, the most common size tire today is the P215/60R16 and the most popular replacement tire is P225/60R16. Michelin’s bestselling HydroEdge tire is advertised a 90,000 mile tire.  In just 25 years that is 50% improvement. 
Just a short 25 years ago a 17 inch tire was way too big to contemplate, but now it’s commonplace. Now SUV’s sport a massive 20 to 22 inch tire. Tire profiles have gone from 50 being low to below that and a 60 is just average. Mileage has gone from low 50,000 to over 90,000.  Tires can run without air since Bridgestone introduced its first generation of run flat tires. 
Changes haven’t come easily.  It has taken extensive studies on super computers, analyzing road conditions, and all of the “what if” questions answered. Questions like what if we added chemicals, or changed belts, or what if the molecules of rubber were shaped differently.  Getting the answers to those questions has taken hundreds of prototypes and a lot of money.  
Altering how the various chemical elements in the tire link together to make the product last longer or stick to the road better or both.  Tires are geared towards specific road conditions, terrain and even regional or geographic locations.  The evolution of the tire has improved safety, smoothness in ride and overall performance of steering and handling.  What seemed inconceivable 25 years ago is the norm now, what will the next 25 years bring?