It would be similar to a hard part throttle pull, kind of.
The fuel should be ok, the timing will be a bit more advanced since you would be at 90Kpa rather than 120+ during an acceleration. Part throttle should not be a big change, 10Kpa maybe?

Up here I think we have had a reduction of fuel quality since my SR is back to some detonation. I have been running mid grade but I no longer detect a difference from regular. I would say at least the Gulf stations up here have changed the blend ratio.