I've been sticking with the same Gulf brand and station that showed me such an improvement in my KR readings a couple of months ago, and to my disappointment, this last tank is starting to show some low octane results. It started slowly but as I get deeper into this tankful, I'm up from a steady 2 to a 5.5. Maybe this sudden change can be attributed to winter gas and if so, I guess I'll have to run a 91 octane tune for the winter or experiment with mixing a couple gallons of E85 with my normal fill up. FWIW, I'm still not aware of the driving activity that produces my high reading. When I watch, full throttle or lift off do not produce a high reading. But in normal driving if I take my eyes off the gauge for a few minutes, a spike is captured. I'm going to see if I can get my KR gauge to give me an audible feedback on high readings.