The Cost to Idle calculator computes the total fuel cost of idling an engine based on the fuel consumption rate at idle (R), the cost of fuel (C) and the duration of time at idle (I).
INSTRUCTIONS: Choose units and enter the following:
Fuel Cost at Idle (FC): The calculator returns the fuel costs at idle in U.S. dollars. However, this can be automatically converted to compatible units via the pull-down menu.
The formula for the fuel cost to idle is:
FC = R • C • I • n
The default value for burn rate of fuel (R) is 0.6 gallons per hour. That's reported to be the burn rate of a Ford F-100 truck at idle. However, one should use the best data available including observed rate measurements from one's own fleet. The following table of idle fuel consumption rates is from the U.S. department of Energy (www.energy.gov) based on a study from Argonne National Laboratory in 2014.
|Vehicle Type||Fuel Type||Engine Size
|Gross Vehicle Weight
|Idling Fuel Use
(Gal/hr with no load)
|Medium Heavy Truck||Gas||5-7||19,700-26,000||0.84|
|Medium Heavy Truck||Diesel||6-10||23,000-33,000||0.44|