[christofoo]

Trip report in brief (details in the log):
Total 1719 mi
Total 43.7 gallons
Average: 39.3 MPG

Sounds decent, maybe, considering hot weather, air conditioning, and the heavy load? Actually I don't think so. For one thing I did 100% of the driving and my P&G / EOC, etc. is pretty well honed.

I need more coast-down runs to verify, and I'm still crunching numbers, but the conclusion I think I'm heading toward is that my Cd is currently higher than stock, and higher than it was with the cargo rack-and-bag.

The most interesting road-trip segment was with minimal wind, minimal elevation change (from end-to-end, with a reasonably shallow hill climb and descent in the middle, no braking or engine braking), minimal AC, where I cruised at 73 MPH for a few hundred mi and the SGII reported an average of 36 MPG.

Speaking of which, I've noticed my engine is going open loop under conditions that surprise me. From a little earlier in my log:
WOT thresholds (LOD where engine goes open-loop on SGII) at various RPM and speeds (from my fuzzy memory):
75 MPH - 3200 RPM - 58 LOD
70 MPH - 3000 RPM - 65 LOD
65 MPH - 2800 RPM - 72 LOD
60 MPH - 2600 RPM - 80 LOD
50 MPH - 2100 RPM - 90 LOD
I actually cease to P&G when I cruise at 73 MPH on flat ground with the AC on because I'm hovering on the WOT threshold at that speed, so P&G becomes a super-long pulse and brief glide - a.k.a. a waste of effort.

Anyone want to run a similar test? My mechanic told me not to worry about my O2 sensor, essentially because the computer isn't complaining about it... and yet this worries me...