New CARFAX data shows that many Americans are behind on critical vehicle maintenance such as regular oil changes and tire rotations. In fact, 29% are behind on oil changes and 44% haven't had their tires rotated as required. About 1-in-5 owners are behind on both services, CARFAX data shows. This information was compiled from alerts and service records for the 35 million vehicles in the CARFAX Car Care program.