The US is still on course to meet its schedule for implementing ultra low-sulphur highway diesel fuel, the Environmental Protection Agency (EPA) has announced.

Under its "Clean Diesel Programme" the EPA is aiming to reduce 2.6 million tons per year of nitrogen oxides emissions from diesel exhaust.

The agency says that its target to make the change during the next five years - the equivalent of eliminating air pollution from 13 million trucks - is on track.

In its latest report, "Summary and Analysis of the 2004 Highway Diesel Fuel Precompliance Reports", the EPA says that by 2006 a total of 95 per cent of all transport diesel - 3 million barrels per day - will meet the 15 ppm sulphur-content standard in 2006.

The EPA says that the fuel will be crucial in extending the life of catalytic convertors, which are now a pre-requisite in new diesel-fuelled vehicles.

Diesel Technology Forum executive director Allen Schaeffer said that the development of clean technologies was an aim that manufacturers and regulators were committed to.

"For the manufacturers of on-highway diesel engines, fuel refiners, and exhaust after-treatment manufacturers, 2007 is the ultimate clean-diesel milestone. From the time these new standards were adopted in 2000, the entire diesel industry has been working toward the fuel mandate," he explained.

The EPA report says that its analysis of more than 120 refineries shows that suppliers will be well equipped to deliver the fuel needed to meet demand.