no technical validation (although in the case of tires, for example, data proving low rolling resistance must be supplied for the designation). All six major U.S. truck manufacturers have one or more complying tractors. Manufacturer compliance with the SmartWay specification is completely voluntary.
SmartWay certification applies to 53-ft or longer dry box van trailers as well. To attain certification, these trailers must have side skirt fairings, a front gap or rear fairing, and SmartWay-approved low-rolling-resistance tires and can have aluminum wheels. The fairings, tires, and wheels can be either provided by the original equipment manufacturer (OEM) on new trailers or retrofitted to older trailers. Several OEMs currently offer at least one SmartWay trailer model, and several manufacturers have developed aerodynamic components that can be retrofitted. EPA has validated trailer side skirts, trailer boat tails, and trailer gap reducers.
As an alternative to the aerodynamic specification for the trailer, the EPA will grant certification upon review of demonstrated equivalent environmental performance for the aerodynamic specification, defined as 5 percent or greater fuel savings using an SAE J13212 test track procedure as modified by EPA.