Sunoco fuels publish the motor octane rating of each grade they sell in addition to the higher research octane rating's. If you use the motor octane rating to compare detonation resistance from fuel to fuel you will be comparing oranges to oranges if you will. Sunoco standard's motor is 105, supreme's motor is 110 and maximal motor rating is 114. Motor rating is the most important in racing engines running at WOT.
Bruce