The Greenhouse Gas (GHG) II emissions mandate proposal covers improved energy efficiencies in transportation, which will potentially affect trailers regarding tire technologies, weight reduction and designs for reducing aero-dynamic drag. Other factors considered include trailer size and the effects of drive cycle and tractor-trailer ratio on the achievable improvements in efficiency as a result of trailer spec choices.
Rolling Resistance Regulations
The choices play a role in fuel efficiency. Low rolling resistance trailer tires, both dual and single configurations, can improve fuel economy when they fit the application. While wide-base single tires (WBSTs) may provide weight reduction and rolling resistance benefits, for many operations they may not match the life and wear characteristics of dual tires – and retreading may not be a practical option.
Specifying lighter weight trailers has its benefits, but most trailer fleets can’t forecast trailer payload weights over the life of the trailer, so for many carriers, reducing trailer weight by purchasing lightweight options for fuel economy doesn’t lead to predictable payback. According to industry experts, weight reduction provides only modest fuel economy improvements compared to other options such as aero-dynamic improvements. Also, weight reduction must be balanced against trailer durability, since lack of durability leads to higher trailer maintenance cost or premature trailer replacement.
Increasingly, fleets have been adding aerodynamic devices to lower drag and increase fuel economy. Research shows that aerodynamic enhancements for van or box type trailers have the greatest potential to improve trailer-based fuel economy – and there are many options. However, they are not applicable for every operation. The use of trailer side skirts for van trailers has significantly grown in past years in certain market segments. Other types of devices such as front or rear devices, or underbelly fairings have seen limited adoption. Damage and maintenance concerns, compared to cost and efficiency improvement potential, may be a deterrent. It varies, but is always worth investigating.
Keeping You in the Loop
Great Dane engineers remain active in the dialog surrounding the GHG II legislation and advocate that proposed regulations recognize the limitations of today’s technologies and should focus on additional improvements through incentives. Great Dane will continue to keep you informed about the GHG II mandate.