Need Help DEF Consumption

Engine, mileage, any codes or lights on? What was the usage before, what is it now? Usage should be about 3%, so 3 gallons of DEF for every 100 gallons of fuel. Heavy loads and temp can affect usage. Look for fluid leaks; crystals around the SCR or doser; cracks in the SCR near the doser; exhaust leaks from the turbo to the SCR; remove and inspect the doser.

 

It’s consumption is directly related to fuel usage. Any bad weather lately, strong winds?

 

Probably too obvious, but could there be a leak in the line?

 

Check for leaks, it will form a bit ball of dried up white colour crystals. If not, it needs to be flow tested to make sure it isn't stuck open.