For the second time in four months, Mazda has announced that it is delaying the launch of its Skyactiv-D clean diesel engine in North America because the unit needs further development.

The Japanese carmaker originally said it would launch the engine before the end of 2013, but announced in September that the launch would be postponed for April 2014.

“While Mazda understands its Skyactiv-D can meet emission regulation requirements without the use of a NOx after-treatment system, it was decided that further development is required to deliver the right balance between fuel economy and Mazda-appropriate driving performance,” the company said in a statement.

What this means is the engine doesn’t quite please Mazda in terms of performance and some more fine-tuning is needed. Mazda said further information, including a timeline of launch for North America, technical specifications and fuel economy will be available “at a later date, closer to launch.” However, it didn’t offer a timeframe for the launch.

U.S. consumers wanting a Mazda6 diesel car must now wait indefinitely – or they can switch to a diesel model from the competition. In the mean time, Mazda’s plan to become the only Japanese automaker to offer a diesel car in the United States takes a new blow.

Mazda is playing the diesel card in order to meet stricter fuel economy standards, while its Japanese competitors have chosen the path of hybrids, plug-in hybrids and electric vehicles.

By Dan Mihalascu

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