FRESNO – The California Air Resources Board (ARB) approved changes to its reformulated gasoline regulations and the predictive model, a tool used by oil refining companies to formulate lower-emitting gasoline in California. Refinements to the predictive model include the greater use of ethanol.

"Clean fuels are essential to reaching healthy air goals in California," said ARB Chairman, Dr. Robert Sawyer. "This action helps fuel providers develop the optimum formula for the cleanest burning gasoline, and it allows ARB to forecast emissions from vehicles throughout the state. The greater use of ethanol in the formulas will also reduce global warming emissions."

The predictive model is a set of mathematical equations that relate exhaust rates of hydrocarbons, nitrogen oxides, and toxics to values of eight regulated properties in gasoline. This in turn is used by refiners to assure that their fuels obtain the required emissions reductions. This gives refiners flexibility in meeting emission limits defined in ARB regulations.

The new predictive model better accounts for widespread use of ethanol and will allow increased use in California's gasoline as part of Governor's Schwarzenegger's Low Carbon Fuel Standard (LCFS) executive order. The goal of the LCFS is to ensure that the mix of fuel sold in California market deliver, on average, lower greenhouse gas (GHG) emissions. By 2020, the LCFS is expected to produce at least a 10 percent reduction in the carbon content, replace 20 percent of our on-road fuels with lower carbon alternatives, and more than triple the size of the state's renewable fuels market.