California regulators have approved groundbreaking new rules that limit the types of replacement tires consumers can buy for their vehicles, marking the first efficiency standards of their kind in the nation. These regulations aim to enhance tire efficiency, potentially saving drivers up to $1 billion annually. While vehicles themselves may not always be fuel-efficient, the new rules ensure that replacement tires will significantly contribute to better fuel economy. The industry is being urged to take action as these tire efficiency rules approach their final stages.