I'm surprised at the lower numbers of the 175 powered CVX. Basically double the prop HP than my boat yet only 12 mph faster. I'm hitting 51 with just myself ( 180 lbs) and approx 12 gal. of gas. I'd think that 175 would push the CVX upwards of 70 - 75 mph.
The challenge out here in Oregon is finding decent gas. The few times I have filled up on the water (with 100% gas, but low octane), it runs better than when I use premium E10 pump gas. It starts, idles, and goes faster on real gas. I would like to find some premium 100% gas to try in it and see what it can do.
The other thing is it starts to chine walk easier when there is less weight in the boat. That has me backing out of the throttle when it is just Lisa & I. The extra weight of passengers keeps it planted and I can stay in the throttle longer and wind it out more. That high of 63mph was with 4 adults and 3/4 tank of gas. A normal day's speed run is 59-61mph.
Fuzzy memory here... I think with automobiles, it is something like the required horse power is squared to go a relative amount faster at a higher speed than at a lower speed. So going from 60mph to 90mph requires four times the horsepower than going from 30mph to 60mph (math is wrong, but it is some logic like that). I wonder if there is a similar calculation for boats? Cars are just dealing with aerodynamics, where as a boat is also dealing with hydrodynamics, and water is a lot denser than air.
-Eric
