A vehicular data conversion apparatus comprising: an acquisition portion that acquires vehicle data from a vehicle; a first storage portion that stores a data processing method for outputting the vehicle data to an outside of the vehicle in accordance with a classification level corresponding to a group, the vehicle data being classified in accordance with a type of the vehicle data into the group; a second storage portion that stores converted data which has been processed in advance by the data processing method stored in the first storage portion; and an output portion that outputs the vehicle data that has been converted in accordance with the data processing method stored in the first storage portion, wherein: the data processing method does not output to the outside of the vehicle the vehicle data included in a group that is included in a classification level having highest confidentiality; the output portion outputs the converted data stored in the second storage portion when the vehicle data is requested from an outside of the vehicle; the first storage portion further stores an update timing in accordance with the classification level as the data processing method; the second storage portion stores the converted data processed in advance for each of classification levels of the vehicle data at the update timing, which is stored in the first storage portion; the vehicle data included in the group included in the classification level having the highest confidentiality is raw information of an estimated value dependent on estimation logic; and a data processing is performed in accordance with the data processing method in advance before a request of data is issued from outside of the vehicular data conversion apparatus. an acquisition portion that acquires vehicle data from a vehicle; a first storage portion that stores a data processing method for outputting the vehicle data to an outside of the vehicle in accordance with a classification level corresponding to a group, the vehicle data being classified in accordance with a type of the vehicle data into the group; a second storage portion that stores converted data which has been processed in advance by the data processing method stored in the first storage portion; and an output portion that outputs the vehicle data that has been converted in accordance with the data processing method stored in the first storage portion, wherein: the data processing method does not output to the outside of the vehicle the vehicle data included in a group that is included in a classification level having highest confidentiality; the output portion outputs the converted data stored in the second storage portion when the vehicle data is requested from an outside of the vehicle; the first storage portion further stores an update timing in accordance with the classification level as the data processing method; the second storage portion stores the converted data processed in advance for each of classification levels of the vehicle data at the update timing, which is stored in the first storage portion; the vehicle data included in the group included in the classification level having the highest confidentiality is raw information of an estimated value dependent on estimation logic; and a data processing is performed in accordance with the data processing method in advance before a request of data is issued from outside of the vehicular data conversion apparatus. the data processing method does not output to the outside of the vehicle the vehicle data included in a group that is included in a classification level having highest confidentiality; the output portion outputs the converted data stored in the second storage portion when the vehicle data is requested from an outside of the vehicle; the first storage portion further stores an update timing in accordance with the classification level as the data processing method; the second storage portion stores the converted data processed in advance for each of classification levels of the vehicle data at the update timing, which is stored in the first storage portion; the vehicle data included in the group included in the classification level having the highest confidentiality is raw information of an estimated value dependent on estimation logic; and a data processing is performed in accordance with the data processing method in advance before a request of data is issued from outside of the vehicular data conversion apparatus.