A new rule requiring heavy-duty trucks and trailers in California to have low-rolling resistance tires and approved aerodynamic devices goes into effect this month.

The rule, which was approved by the California Air Resources Board in December 2008, applies to 53-foot or longer box-type trailers as well as the heavy-duty trucks that pull them on California highways.

These trucks and trailers operating in California must meet the new requirement by either replacing or retrofitting the vehicles according to a staggered schedule.

"This important measure is ultimately going to improve our air quality, save hard-earned dollars and promote energy independence by helping to decrease our consumption of fuel," said Mary D. Nichols, ARB chairman. "It makes good environmental and economic sense for business owners and for those of us who live and breathe in California."

CARB believes the regulation will save about $8.6 billion, as well as 750 million gallons of diesel fuel in California and 5 billion gallons of diesel fuel across the nation. It's also expected to reduce greenhouse gas emissions by about 1 million metric tons of carbon dioxide-equivalents by 2020, statewide.

The new rule is part of AB 32, the state's climate change law signed in 2006.

According to the regulation, by Jan. 1, all 2011 model year and newer sleeper cab trucks that pull 53-foot or longer dry van and refrigerated van trailers must be SmartWay certified, which includes installing low-rolling resistance tires. Model year 2011 and newer day cabs are only required to use SmartWay verified low-rolling resistance tires.

All pre-2011 model year tractors that pull affected trailers must use SmartWay verified low-rolling resistance tires starting Jan. 1, 2012.

In addition, 53-foot and longer box trailers that are 2011 model year and newer must be either SmartWay certified or retrofitted with some combination of SmartWay verified technologies such as rear fairings, trailer side skirts, trailer front gap fairings and other devices. They must also be fitted with low-rolling resistance tires.

For more information, click here.