My 2001 Maxima GXE came from the dealer with a full tank of free (sh*tty) 87 octane gas. After that I always used 93 octane gas.

During the first tank of gas the knock sensor presumably retarded the timing to prevent knocking, the question is will the timing be automatically adjusted back (advanced to normal) after I started using 93 octane gas? How can I tell? From engine performance or else? In the old days I remember to disconnect the battery to reset the ECU.

Thanks, Yuan

 

You could reset the ecu but it's probably not necessary. The engine will use the most advanced timing available until it sees knock, then it will start to retard the timing. My old XR4TI had a octane sensor that automaticlly read what kind of gas was inside. I don't know if maximas have this or not.

 

you don't do a thing... just buy the best octane you want and let the engine management do it's thing.... you probably will not notice a big differance unless you are really spinning the engine.... but for most everyday driving you can't tell.... but the timing is retarted or advanced as needed...