With our truck’s laborious duty cycle (DEF consumption is relative to engine load) and the XD’s small, 4.5-gallon DEF tank, the 44 gallons we fed the Nissan over 40,000 miles, at roughly $6 per, came in many small doses.
Wow. That DEF usage is pretty high. In 10,000 miles (16k km) I think my TDI used 3 gallons.