ALLDATA is the largest single source of OEM (Original Equipment Manufacturer) information available. ALLDATA provides vehicle manufacturers' diagnostic and repair information.br br The company was founded in 1986 in Elk Grove, California by entrepreneur Rod Georgiu and a team of computer and automotive professionals who foresaw how automotive technology would soon transform the vehicle repair industry. As computer technology took hold, ALLDATA began compiling the largest single source of OEM information available.