The European Commission should adopt less stringent nitrogen oxide limits if it wants to promote cleaner diesel engines.
Dr Jurgen Stein, research and development director at Daimler-Benz, said such a move would allow for considerable improvement in fuel consumption and reduction of particulate emissions in diesel engines.
Stein, speaking in Brussels last week at the annual gathering of Europe’s internal combustion engine manufacturers – Euromot – said industry faced a steep hill in development to meet the demanding exhaust emission limits being discussed by the commission.
The proposed Euro 3 and non-road Tier 3 standards represent demanding levels which are feasible only with considerable efforts and by applying the most modern engine technology.
`The time available is very short and only manufacturers which have already made progess towards this goal will be able to offer customers corresponding engines in time,’ said Stein.
These engines would have a fuel consumption penalty of about 4-8% compared to existing Euro 2 engines, he said. `This should be considered when it comes to setting limit values: a slightly more lenient NOx limit (about 5g/kWh) will have a favourable effect on fuel consumption and particulate emission.’
Stein also called on diesel fuel manufacturers to pull their weight. `Further reductions of NOx and particulate emissions after 2000 require the use of exhaust after treatment systems,’ he said.
In addition to tighter emission limits, the industry faces new noise restrictions.
The quest to reduce emission levels by industrial engines will, however, increase the need for cooling – which creates more noise pollution.
Dr Giorgio Billi, chief applications engineer at Lombardini, called for a delay in the proposed noise deadlines. `Equipment manufacturers will have engines meeting stage-two emission limits available only shortly before the date when their use will become compulsory.
`Only at that point will it be possible to start evaluating whether the noise limits can be met and how to modify the machines to achieve that goal.’
By Anthony Gould