Coincidence

Chuck:

The use of lower octane fuel will cause pre-ignition, and the knock
sensor will detect that. The computer will retard the ignition to the
point that knock will be reduced.

My 97 Maxima requires not less than 93 octane fuel.

I'll bet that your car requires high octane fuel.

With high octane you get less pre-ignition, less knocking, no knock
sensor signals being sent to the computer, less ignition retarding, and
no engine condition light.

With higher octane fuel the computer may have advanced the ignition
appropriately due to no pre-ignition, and that should give you more
power and mileage. The higher octane fuel itself provides no added power
or mileage, and it is not of higher quality. It merely burns slower to
limit pre-ignition in high compression engines.

Ralph Hertle