Volkswagen's newest diesel engines are clean and will meet future emissions limits, the German car manufacturer's Head of Development Ulrich Eichhorn told German news agency DPA on Friday.

"We solved the problem of nitrogen oxide with the new engines," Eichhorn claimed. "This will also meet future emissions limits on the road."

In September 2015, Volkswagen was found by the United States Environmental Protection Agency (EPA) to have deliberately and illegally manipulated many of their diesel engines to activate controls during testing to mask their true amount of NOx emissions. The amount of NOx emitted by the cars in real-world driving was up to 40 times that displayed in testing.

"The problems that the internal combustion engine had in terms of the environment and pollution were NOx and particulate matter," said Eichhorn, referring in the latter to the fine particles of dirt, dust and other tiny matter emitted into the air from engines.

"This fine dust is only an issue for 'Otto' direct injection engines (gasoline engines), a small issue, because that represents only 2.0 percent of the total fine dust load, Eichhorn elaborated.

"With modern diesel, this fine dust is no longer an issue thanks to soot particle filters and in terms of gasoline engines, we will introduce these particle filters over the next two years."

Excess NOx emissions have a devastating effect on health in Europe and around the world. Findings published in the respected scientific journal Nature earlier this year revealed that a minimum of 38,000 people around the world die early every year as a result of the failure of diesel vehicles to meet official emissions limits in real driving conditions.

The deaths are mostly due to heart and lung disease, with the majority occurring in Europe as a result of excessively polluting cars, inland waterway shipping and other factors.

Hunting for alternatives

Since the Dieselgate scandal erupted, debate over the future and long-term viability of diesel has raged in Europe and beyond. While the prospect of diesel engines meeting future emissions limits — as promised by Eichhorn — is a minimum short-term requirement, there is an increasing expectation that car manufacturers will invest heavily in electromobility, namely a shift from the use of fossil fuels towards electric and other alternatives.

Volkswagen has already pledged to make major investments in the area. Chief Executive Matthias Müller said last year that by 2025 he expects electric cars to account for a quarter of Volkswagen's annual sales.

This is in line with other developments in the industry. Jaguar Land Rover announced on Thursday that it would make electric or hybrid cars only from 2020, following on from Volvo's decision in July to achieve the same by 2019.

But the problem of NOx is unlikely to go away any time soon. The aforementioned Nature study, published in May, found that excess global NOx emissions are rising rather than falling, and that unless strict pollution controls are put in place and enforced, the annual death toll could swell to 174,000 over the next 25 years.