The current F1 rulebook has limited certain areas of car improvement: a 10-year freeze on engine development is in place, Bridgestonetires are standard issue to every team and testing in season is restricted.
Sony recently filed a complaint against BridgestoneTires over an advertisement featuring the same actor, allegedly portraying Kevin Butler as a Bridgestone employee, endorsing its tire products and a promotional program featuring the competing Nintendo Wii game system.
Bridgestone says that Ecopia tires (as seen on the Nissan Leaf) improve rolling resistance 36 percent, which means a 4 percent fuel economy improvement (5 percent for Dueler truck tires).