In order to encourage the use of idling reduction devices in large trucks, the Energy Policy Act of 2005 allowed for a 400-pound weight exemption for the additional weight of idling reduction technology. States were given the discretion of adopting this exemption without being subjected to penalty.

Since then, most States have passed laws which allow trucks to exceed the maximum gross vehicle weight limit by an additional 400 lbs (white States) Other States have a 400 lb weight allowance which is granted by enforcement personnel (light blue States). Four States have legislation pending at this time (green States) and another four States have not adopted the weight exemption.

States Adopting 400-Pound Weight Exemption for Idling Reduction Devices, 2010

An additional incentive for equipping large trucks with idle reduction technologies was in the Energy Improvement and Extension Act of 2008. The Act excludes certain idling reduction devices and advanced insulation from Federal excise taxes. Products which are eligible for the tax exemption include:

  • fuel operated heaters,
  • battery air conditioning/heating systems,
  • auxiliary power units/generator sets,
  • thermal storage systems, and
  • shore connection systems

Supporting Information

State Recognition of the 400-Pound Auxiliary Power Unit Exemption to the Gross Vehicle Weight Limit
States Allowing ExemptionStates where Allowance is Granted by EnforcementStates where Legislation is Pending for ExemptionStates That Have Not Adopted the Exemption
ConnecticutIowaMassachusettsNorth Carolina
DelawareLouisiana Rhode Island
Indiana*Maryland Tennessee
NebraskaNew Hampshire  
New MexicoNew Jersey  
North DakotaNew York  
OregonSouth Dakota  
South CarolinaUtah  
West Virginia**   

* Effective July 1, 2010
** Effective June 11, 2010
Sources: U.S. Department of Energy, Energy Efficiency & Renewable Energy, National Idling Reduction News, April 2010.
U.S. Environmental Protection Agency, SmartWay Transport Partnership.

Return to 2010 Facts of the Week