Three smog-eating cars hit Southern California's busiest freeways earlier this month, kicking off a two-month test of a radiator designed to convert ground-level ozone into oxygen.

Two Ford Contours and a Ford Windstar equipped with the special Engelhard Corp. pollution control system will be driven 10 hours a day, six days a week by six students from GMI Engineering and Management Institute."These drivers may well have one of the worst-sounding jobs in L.A.," said Lou Ross, Ford's chief technical officer. They will drive congested freeways in Los Angeles, Orange, Riverside and San Bernardino counties.

"The hours (at least 10 a day) are long, and I guess it's not exactly the place you want to spend your summer, going out of your way to get stuck in L.A. traffic," said Jason Roycht, a native of Newark, Del.

"But it's exciting for me to be involved with the project. The new system has great potential," said Mr. Roycht, a graduating senior at GMI, a private automotive and industrial engineering school in Flint, Mich.

Engelhard's PremAir catalyst system - specially coated radiators that convert ozone into oxygen - could revolutionize emission technology and lead to reduced levels of ozone, smog's key component, company officials said.

"It actually takes ozone in the air and turns it into oxygen that we can breathe," said Terry Poles, director of business development for Iselin, N.J.-based Engelhard.

The driving tests are designed to determine durability of the coating and how much ozone it will scrub from the air on a daily basis, Mr. Poles said.

"It would be a terrific way to turn cars into machines that destroy pollution as they are rolling down the road," said Pam Kueber, a Ford spokeswoman.

Engelhard and Ford believe the coating will last at least 100,000 miles.

"Engelhard initially estimated that it could cost upward of $500, but we believe that is a high number, and it could come in significantly less," Ms. Kueber said.

The Engelhard PremAir system should destroy about 90 percent of the ozone that passes through a vehicle's radiator, said Dan Pellissier, a spokesman for the California Air Resources Board.

"It would be another weapon in the arsenal" to help the region meet federal pollution standards that take effect in 2010, he said.