Based on a worksheet developed by Argonne National Laboratory, the idle fuel consumption rate for selected gasoline and diesel vehicles with no load (no use of accessories such as air conditioners, fans, etc.) varies widely. Both compact sedans with 2.0 liter engines each consume about the same amount of fuel at idle (0.16 and 0.17 gallons per hour respectively), despite differing fuel types. By comparison, the large sedan with a 4.6 liter engine consumes just over twice as much fuel at idle. Of the remaining vehicle types listed, the transit bus consumed the most fuel while idling at nearly 1 gallon per hour (gal/hr). The gasoline medium heavy truck category with a gross vehicle weight (GVW) of 19,700-26,000 lbs. consumed more fuel at idle than the diesel medium heavy truck category at 23,000-33,000 lbs. GVW.
Fuel Consumption at Idle for Selected Gasoline and Diesel Vehicles
Note: The passenger car results are from a study by Argonne National Laboratory; the delivery truck results are from a study by the National Renewable Energy Laboratory; the tow truck, transit bus, combination truck and bucket truck results are from a study by Oak Ridge National Laboratory; the tractor-semitrailer results were from a study by the American Trucking Associations; both of the medium heavy truck results were from a study published in the Journal of the Air & Waste Management Association. For details on these results, please see the individual studies referenced by the source.
|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|
Source: Argonne National Laboratory, Idling Reduction Savings Calculator, accessed December 2014.