I checked my iam yesterday after not checking It for a while cuz it was always 16 and guess what it was at (5) I was like o sh yet. Went out data logged driving hard and it had the timing low every were. Couldn’t get a knock to register but knew it had to be there so I figured bad gas everything else look good. Added 1g of xylene to 8 g of 91oct which would make it 93.8 oct and after 10 miles bam! (16) no reset of the ecu no tricks just went out and drove it hard trying to experience every kind of load. I hate cali gas I love free data loggers! Mods (vf34 ,pinks, cobb ots map for 91oct, divorced downpipe, gutted stock 3rd cat and stock catback. now I will start cutting back on xylene till I find the happy spot. I think ¼ g to ever 8 might be enough but we will see. O I only run half tank for weight reduction. lol :banana: