Mazda delays Skyactiv diesel launch in U.S. again

LOS ANGELES -- For the second time in roughly four months, Mazda has delayed the U.S. market launch of its Skyactiv diesel engine for emissions-related issues.

Originally scheduled to debut in the Mazda6 late last year, the automaker said today it has delayed its first diesel engine in the U.S. market until further notice. Mazda says its 2.2-liter Skyactiv turbodiesel can pass U.S. emissions regulations, but that more work is needed to ensure the engine's performance meets company standards.

Mazda spokesman Jeremy Barnes stressed that the diesel program is still active and that the company still plans to launch a Skyactiv diesel-powered vehicle in the U.S. market. Mazda first postponed the launch of its 2.2-liter turbodiesel in the Mazda6 mid-sized sedan from late 2013 to April 2014 because of delays in emissions testing.

Still, the delay is another bump in Mazda's plans to add a diesel to its lineup, a key part of its strategy to improve fuel economy amid toughening regulation.

A key technological difference Mazda hoped would set it apart from competitors' diesels was that its Skyactiv engines would be engineered to meet U.S. emissions requirements without the added cost and complexity of exhaust after-treatment systems. Other automakers use the systems to reduce the nitrous oxide output of their diesel cars in the United States.

"There are challenges with meeting the emissions standards without after-treatment systems," Barnes said. "We believed our Skyactiv technology can meet it -- and it can -- but the challenge is engineering a car that delivers the kind of performance that a Mazda needs to have and we're unable to do that given where we are right now."

Following the delays, Barnes said Mazda engineers are now looking at re-engineering the Skyactiv diesel engine to include either a nitrous oxide-reduction catalyst or a urea after-treatment system to cut NOx emissions. The company is also looking at ways to continue without after-treatment, Barnes said.

In its statement, Mazda said a launch timeline for its Skyactiv diesel engine would be announced at a later date closer to launch.