Did you perform the same test on your old 4 horse that you did on the two 6 hp/4 strokes? It would be interesting to see the results. I too, have a Tohatsu 6hp, 2007 model, ultra long shaft on a North American Spirit 23, probably about 3400#s with all the s*** I've got on board. I get about 5.2 knots(GPS) in light air, and I can tell the unit is no where near top end..if I drop it down a bit, I can still get about 5, but again, light air, a headwind of any significance knocks it down a half knot or so, maybe a bit more. I have to agree with you on the economy.. on the first few "fillups".. I think the tip to the dockhand was more than the gas.. and I"m not the biggest tipper on the water. This is the only engine I have ever had on this vessel, so I have nothing to compare to; however, when I get it wet again next week, I intend to put an older 9.9 two stroke on for a comparison. Again, it would be interesting to see how those "bollard pull" results from your old 4hp/2stroke measure up to your newer 6. What would be even MORE interesting would be the same test between a NEW Tohatsu/Nissan, 4, 5, AND 6 hp.