OEE, MTTR and MTBF are a few examples of maintenance measures given in the IATF16949 standard under clause 8.5.1.5. You can use any other measure appropriate for your organization since it is not a requirement (not a "shall") to use only these objectives. However, there is / can be sometimes a conflict regarding why these measures are not used.
Hence, if you use MTTR-MTBF, it meets the requirement of this clause.
Also, include a measure to monitor Preventive maintenance compliance objectives - such as Plan Vs Actual preventive maintenance %.