California Code, Public Resources Code - PRC § 25772

On or before July 1, 2007, the commission, in consultation with the board, shall, after appropriate notice and workshops, adopt and, on or before July 1, 2008, implement, a tire energy efficiency program of statewide applicability for replacement tires, designed to ensure that replacement tires sold in the state are at least as energy efficient, on average, as tires sold in the state as original equipment on new passenger cars and light-duty trucks.