We took Clifford to Elliot Bay on a beautiful sunny day in January to obtain some performance data on the re-pitched prop (16.5 to 18). The wind was calm, we had smooth water, a slack tide, and warm weather. The view of Magnolia, Seattle and Mt. Rainer was unobstructed. A short video of the scenery is below.
We changed the pitch to 18 inches in Sept 2020 and compared the performance between the two props. The new prop does not increase the fuel consumption if the RPM is kept below 3000, adds about 1.5 knots at all RPM values, and increases the KPG significantly below 2500 RPM. If you want to cruise at 10 knots, you can now run at 3000 RPM instead of 3250, which lowers the noise level in the cabin. At speeds below 10 knots, the new RPM values for the same speed will be about 500 RPM lower than before. In summary, if you cruise at 2800-3000 RPM, you’ll have a quieter ride, get slightly better fuel economy, but have the same speed with the new prop that you had at 3200 RPM with the old prop.