OIL CONDITION ESTIMATION APPARATUS, VEHICLE CONTROL APPARATUS, VEHICLE CONTROL SYSTEM, AND DATA ANALYSIS APPARATUS

An oil condition estimation apparatus to be applied to a vehicle in which oil is agitated by a rotator includes a storage device and an execution device. The storage device stores mapping data for defining mapping. The mapping includes, as input variables, a speed variable indicating a rotation speed of the rotator, and a pressure variable indicating a pressure of the oil, and includes, as an output variable, an air bubble variable related to air bubbles contained in the oil. The execution device executes an acquisition process for acquiring values of the input variables, and a calculation process for calculating a value of the output variable by inputting, to the mapping, the values of the input variables acquired through the acquisition process.