Pirelli is the 7th largest tire manufacturer in world, particularly devoted to high value tires where it is leader in prestige tires with more than 50% of market share in the Original Equipment channel, constantly engaged in the development of innovative products. This study is inserted in the research and development activity of the company and it is aimed at the experimental evaluation of the design/process leverages able to modify the tire performance. This thesis work in particular deals with effects of the cap strip layer in controlling 6 tire characteristics: high-speed behavior, final product dimensions and tolerances, tire stiffness in the 3 directions (radial, longitudinal and lateral), breaking energy, rolling resistance, contact patch dimension, shape and pressure distribution.