How Much DEF Do I Need To Use?
The amount of DEF used by any given piece of equipment depends on three things:
- Size of truck and engine and manufacturer
- The configuration of the engine and transmission
- The weight of the load on the equipment and how heavy a foot the driver has.
Class 8 vehicles (including most tractor trailers) use between three and 8 gallons of DEF for every 100 gallons of diesel fuel. Off-road machinery, using a full selective catalytic reduction system (SCR), can use eight to 10 gallons of DEF to every 100 gallons of diesel fuel.
As a rule of thumb, trucks running on the highways usually need to fill the DEF tank every third time they fill up the truck with diesel. Smaller vehicles and light duty trucks can do it at every oil change. With heavy equipment, DEF consumption is hard to gauge due to the potential engine configurations, idling times and loads being put on the machinery.
What Happens When DEF Runs Out?
The trucks and machines that use DEF have a built-in monitoring system. The driver will receive periodic warnings when the DEF is running low. If the DEF runs out, the system will go into the derating or commonly called Limp Mode which mean a significant loss of power. If the driver does not refill or add DEF into the reservoir, the system will eventually shut down. This is why it is important for all Owner/ Operators of trucks or heavy equipment to have a gallon of DEF stowed onboard to prevent a shutdown.
How Much DEF Should You Have On Hand?
For those companies that need to manage a fleet of diesel vehicles, it is important to keep at least one week's worth of fluid on hand. It could take several days to schedule delivery of additional product delivered.
For a small fleet, 3 to 4 semi-trucks, a 55-gallon drum is usually enough. For larger fleets (10 or more vehicles), going with one or two 330-gallon totes is the more economical option. Adding an 500 Gallon above ground self contained unit or a underground 1000-gallon tank is another option for the really large fleets. Monitoring fleet usage over time will indicate the amount of fluid used during an average week or month.The Tanks and equipment needed to dispense DEF is completely different from conventional fuel dispenser’s due to the high corrosive nature of DEF.
If you need assistance in setting up DEF as part of your fuel management program, contact us here at Innovative Fueling Solutions. We offer all the equipment options and expertise you need for adding DEF to your fleet's fuel management program. Contact Glen Harding or Ted Billingsley.