On our Clinton trip a few years back it seemed like our flight of 5 averaged in the 90-95 knot category if my memory is correct. However, I have recently seen several 152 owners bragging of 115 knots speeds. Makes me feel like I wasted money on the 177, but ASI's are not the only thing that registers high at times.
One thing I have discovered is if you make the calculation for TAS and calibrate that, my GPS and ASI are typically very much in agreement. I was amazed at how much of a difference it is. On my card, I routinely show 120-125 mph, but TAS is in the 143-145. After this I apply the "correction" and find my bird makes book at about 137-142 on nearly every flight.
