The Fleet That Can’t Be Moved: Why You Should Not Leave DEF Tank Empty


TruckEasy to use, practical, and most of all, fuel-efficient—these are just some of the reasons why most people are choosing to add Selective Catalytic Reduction (SCR) technology to their fleets. An after treatment technology, SCR can minimize nitrogen oxide emissions up to 90%. With diesel exhaust fluid (DEF)added to the SCR, truck fleet drivers ensure that only a safe mix of nitrogen and water leaves their engine.

If your fleets feature SCR technology and DEF, one of the things you should always remember is to never let the tank run out of fluid. Leaving the DEF tank empty will leave you with an engine limping on speed and power or worse,a huge truck fleet that never moves.

Unless you want to be stuck in the middle of a road somewhere, do not ever forget to refill your DEF tank. Work with diesel exhaust fluid distributors to ensure that your fleet—and your business—keeps running.

When to Refill Tanks

Knowing when to refill tanks apparently is not rocket science. When the U.S. Environmental Protection Agency implemented new emissions-reductions rules, they required truck manufacturers to place features that will keep fleet drivers from running vehicles without fluid.

Engines that have SCR technology feature a gauge that allows you to see the DEF fluid level—like that of a typical fuel gauge. They also have a dashboard of flashing lights that will alert you when the DEF tank is running low on diesel exhaust fluid.

See the Signs

When the DEF tank level reaches 10%, the amber warning light turns on. The light will begin flashing when the level drops to 5%. You will see a solid amber warning light when DEF tank level dips all the way down 2.5%. The vehicle will eventually slow down, and speed may be limited to 55 mph or reduced to 25 or 5mph.

Pay attention to DEF warning lights. Ignoring these signs will just cause hassle and big headaches for you and the business.