American Towman Magazine - January 2022

Page 54

This quick-reference chart shows how temperature affects the shelf life DEF. A heating element in a truck’s DEF tank thaws out frozen fluid.

DEF TIPS FOR COLD WEATHER Handling and storing DEF can be challenging in wintertime for tow drivers on the road and for those tow businesses storing it in a garage. Some things to keep in mind about DEF use and storage in winter include the following: • If DEF freezes in the vehicle, do not put any additives in the tank to help it melt. DEF needs to remain pure for it to work correctly. • In cold weather, the vehicle will generally start without an issue and the DEF tank on the vehicle has a heating element that can quickly thaw the DEF. No worries, since on-spec DEF is specifically formulated to allow the fluid to thaw at the proper concentration. • Like water, DEF will expand up to seven percent when frozen and can damage a storage tank if it is full or nearly full when it freezes. Keeping a tank that you think may freeze slightly less than full is a good idea.

and the quality to preserve the emissions control system and the environment.


One of the main challenges for tow drivers is knowing the brand of DEF they are being sold, as many fill-up locations don’t identify the manufacturer and brand name on the receipts to their customers. Regulations in many states require this information be provided when bulk DEF is delivered to the location. Without it, filling stations cannot provide the information on dispenser receipts. So it could be difficult for drivers to confirm they are buying DEF that is licensed by the American Petroleum Institute (API), under its Diesel Exhaust Fluid Certification Program, unless clearly marked, or the information is otherwise provided. Yet this detail is important, as many diesel engine manufacturers recommend that drivers use API-licensed DEF. On the other hand, drivers accustomed to purchasing DEF in containers should look at the expiration date on the bottle and be sure to use it before this date as the product has a limited shelf life. (That’s why some tow business will pay extra for a pallet smaller containers of DEF, rather than buying it in bulk.)

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If a date is not present, ask for the most recently delivered DEF products.


Storage conditions also have an impact on its quality. DEF can be expected to have a minimum shelf life of 12 months or even longer in optimum conditions. So check the label for recommended storage temperatures. API advises that you don’t store if for too long in your truck once you purchase it, especially if the storage area in the vehicle is routinely hotter than the recommended storage temperatures displayed on the label. Be sure to look for the API certification mark on the bottle as well.


API has found that the biggest misconception by fleet managers is the belief that if the urea concentration of their DEF is on spec, then the DEF meets the required quality. While it is absolutely true that the concentration is very important, there are many other important quality characteristics built into the ISO 22241 specification. As already noted, DEF is composed of 32.5 percent technically-pure urea in pure water. Each of these components is critical to the manufacture