DWL and timing advance gauges
 

I greatly improved my DWL technique by following PaleMelanesian's recommendation of 75-80% load as a target--started just yesterday. Already see results on some mpg-deadly hills on my commutes. Observation and question: I monitor timing advance on my Ultra Gauge and sometimes, usually driving at 90%+ load but sometimes down near 80% the timing advance reads a negative value. So I back off the throttle slightly to return the reading to a positive number. So I am driving between 75-80% load and the low end of the positive timing advance turf. Good? If so, can I improve it? How? What do you think?