Cruising speed

[thagoort]

I have a new Ranger 31 tug that we intend to cruise. On long journeys, what is a safe top speed to run the 300 HP Volvo for several hours?

 

[jcarrdive]

The d4 will easily run at 3200 all day long I am told. We have a new r31 also, so I have asked. We get around 1.4 miles per gallon at that speed. We don't generally run that fast but do occasionally and they say it is good for the d4 to be run up to "wide open" reasonably often for a bit.
Jeff and ela
Wallowa r31