An automotive gear oil is designed specifically for gears. The vehicles gear system involves metal-on-metal contact, which may cause heat and wear. Oil protects these moving parts by reducing friction and transferring heat away from them. The parts can be damaged by excessive scouring and corrosion if insufficient lubrication is used. Eventually, this deterioration can harm the performance of the vehicle and result in costly repairs. When oil is overused, it no longer serves its purpose, which reduces the overall condition of the transmission and gear system. Therefore, it is recommended to regularly change gear oil to keep the vehicle in good condition and avoid costly repairs later on.