It will run on it but with reduced performance .
The motor features a knock sensor that reports fuel octane values to the
ECU. When a lower octane is used, knock is present and the ECU retards
ignition timing to prevent engine damage.
The ECU will continually reduce timing until knock values are with in a
predetermined safe range but it will only provide a limited range of
adjustment.
What that range is, I can't tell you because I play with the 4G63.
I would limit the time spent at full throttle when running on regular just
to be safe.