depending on the MFG and everything there can be one basic computer to 16 computers. This why a car get water damage never buy. Even after being dried clean up the computers will not work like they should. Why so many. So have do with impact for air bags speed fuel. and measure many things oil fuel oil pressure Battry electric cars may have a few more than many but depends on a lot. with safety keeing car in a line. auto control. out stop .