Attached is fuel consumption data for the Volvo Penta
TAMD 63L engine @ 310 hp , which was a slightly later version of your TAMD 61 @ 306 h.p. I have attached the data for the 63 because it is in tabular format, and easier to read than the graph data for the 61, but the consumption numbers are virtually the same.
You will note that the data is "propeller load, exp. 2.5" which means that it reasonably accurate for a vessel with a planning hull
. If your vessel has a semi- planning hull
the consumption might differ slightly, as partial load fuel consumption is always dependent on the actual hull resistance of the vessel.
Hope this is helpful. Feel free to inquire if you have further questions.