Hello Johnson and welcome to the DOW site .
A truck that size works very well for working around the farm and short trips running totally from wood. When you are considering driving 90 miles a day it may create a problem . Your speed will be held to 50 -60 mph without over heating the gasifier . If more speed is needed you will have to blend in gasoline.
A truck that size driving hyway speeds will consume near one and half pounds per mile. ( lot of wood )
If you drop down one size on the trucks to the dakota you can expect to drive 60-70 mph and use about a pound of wood per mile .