Diesel Exhaust Fluid (DEF) FAQs

Posted on February 18, 2014 in Featured, Maintenance, Spring.

It’s important to know what you’re putting into your machine. Below are some of the most commonly asked questions—and their answers—about Diesel Exhaust Fluid (DEF) from New Holland:Diesel Exhaust Fluid

How much DEF will my New Holland tractor use?
The consumption rate of DEF will vary depending on engine load, but in typical agricultural applications, it ranges between three to five percent of diesel fuel consumption. Depending on engine load and implement size, a high-horsepower MFD tractor consuming 10 gallons per hour and working 400 hours per year would typically use 100 to 200 gallons per year. In the new generation of New Holland tractors, it’s estimated that for every gallon of DEF, you save TWO gallons of diesel fuel—thanks to the enhanced fuel economy allowed by the DEF-enabled New Holland SCR technology.

Where is the DEF stored on the tractor?
DEF is stored in a tank on the tractor next to the fuel tank. The DEF tank on a New Holland tractor has a capacity such that it needs to be filled every other time you refuel. DEF tanks range in size from 15 to 50 gallons depending on the tractor size and horsepower. The DEF tank fill opening is designed to accommodate only a DEF fill nozzle, which ensures that only DEF is pumped into the DEF tank. Standard diesel fuel nozzles do not fit into the DEF tank opening.

Will DEF freeze in the tractor tank?
DEF begins freezing at 12° F (-11° C). If DEF freezes, the tractor will start and run normally, with no engine de-rating. The tractor DEF tank heater, which utilizes the engine cooling system, will quickly thaw the DEF tank. Even if DEF is frozen in the tank, the tractor will have full power while the DEF thaws. To maximize shelf life, ideal storage temperature for DEF is between 12° F (-11° C) and 86° F (30° C). However, you can store DEF outside these temperatures as long as it’s rotated on a seasonal basis. Freezing and thawing does not change the chemical properties.

How do I know if my tank needs filling?
On New Holland tractors, the A-post instrument cluster has a DEF level gauge, which shows the fluid level and indicates when it’s time to refill. If the DEF tank fluid level becomes low, a series of warnings alert the operator after DEF reaches less than 10 percent of capacity. If the DEF tank reaches less than 5 percent, the tractor engine power will de-rate, but power is still available to allow the operator to return to a convenient location to add DEF to the tank. You can easily manage the DEF level by simply refilling  the DEF tank every other time you refuel.

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