Prolonged use of inadequte octane can result in, but is not limited, to spun bearings. When the low octane rating of the fuel is unable to resist detonation or pre-ignition with the high static compression ratio of the B18C1, the force of the igniting air/fuel mixture is diverted onto the piston before the optimal amount of crankshaft rotation is achieved (usu. ~15º ATDC). This causes large amounts of pressure to be applied to the rod bearing(s) which can deform the round uniform shape of the bearing 'causing lubrication and cooling problems and balancing/clearance issues as your engine
slowly comes spiraling down from VTEC-kingdom with every damaging crank rotation afterwards...a slow long death as that little motor waits for its day to come when the bearing finally seizes up and punches a hole in the side of the block. Then...then there the motor will take its last breaths, dripping its lifeblood (that's the oil) away on the pavement as it tries to get back up with every crank of the starter, peering into the distance of the Mustang just past but seeing nothing...the little engine cannot lose...it cannot lose...no, it's over. :twisted:
Okay, okay. Maybe not as graphic as that description but take care of your car. Run the right octane for your car--whatever the number really is.