WASHINGTON - The state of New Jersey owns more than 2,200 cars and light trucks that run on E-85, a cleaner-burning fuel mix of 85 percent ethanol and 15 percent gasoline, according to www.stateline.org. But a state worker in Trenton, N.J., would have to drive nearly 30 miles one-way to get that special fuel in downtown Philadelphia.

New Jersey’s “flex-fuel” vehicles are being run only on dirtier unleaded gasoline because the Garden State is one of seven where there are no state-owned or retail pumps that dispense E-85, including Alaska, Hawaii, Maine, New Hampshire, Rhode Island, and Vermont. Although flex-fuel cars can use conventional gasoline, they emit more carbon dioxide than if they used the mostly ethanol mix.

Nationwide, state governments have bought more than 40,000 flex-fuel vehicles to meet requirements of the federal Energy Policy Act of 1992. The act was intended to reduce the nation’s dependence on foreign oil, but 30 states do not provide E-85 at any state-owned fuel depots, and only 18 states have more than 10 retail sites with the special fuel.

In theory, the 1992 law should have been a boon for ethanol, but states have exploited a loophole: The act does not actually require states use any alternative fuel. When the law was passed, states were required to buy for their fleets a small percentage of alternatively-fueled vehicles and mostly purchased vehicles that ran only on compressed natural gas or propane.

But by the late 1990s, domestic automakers were mass-producing flex-fuel vehicles that could run on gasoline or alternative fuel, and states started snapping them up to meet the law’s growing requirements. These new flex-fuel vehicles also relieved them of using E-85. The federal law required that by 2001, 75 percent of new state vehicles had to be able to run on something besides gasoline, with exceptions for law enforcement cars and heavy equipment, according to www.stateline.org.

Governments and commercial retailers may be unwilling to invest in the equipment to pump ethanol because the national Underwriters Laboratory removed its safety endorsement for E-85 pumps, raising liability concerns for both retailers and government fleets.

Many states are now moving to cut their gasoline use by purchasing hybrid vehicles that get greater efficiency by using electric engine to complement a gasoline-powered motor.