Lessons learned from diesel filter problems

Energy Minister Pete Hodgson today released a government report on the diesel-filter blocking problem that occurred between March and May this year.

Extensive investigations into the problem found no clear cause for the filter blocking, which affected about 4 percent of New Zealand's diesel engines.

"I asked both the New Zealand Refining Company and the Ministry of Economic Development to investigate the problem and its likely causes," Mr Hodgson said. "Used filters and samples of diesel fuel were tested. Unfortunately no conclusive results were obtained, although the tests indicated a possibility that a new winter additive may have contributed to the blocking.

"The filter blocking problem is still subject to commercial and legal discussions amongst the companies involved. They are still investigating the cause as part of this process and I understand this investigation is focused on the chemical interaction between the additive and the diesel oils being produced by the refinery at the time. The results of this, when known, should help clarify the cause."

"While it is frustrating that no clear cause has yet been found, some important lessons have been learned and action is being taken to prevent this type of problem from recurring:

·the industry has ceased the use of the new additive and will be considering other options for additives for next winter;

·the refinery has invited the Ministry of Economic Development to participate in a planned review of its quality management systems, and;

·the Government is looking at regulatory changes to avoid similar problems happening in the future.

"The Government is publicly consulting on a review of the Petroleum Products Specifications Regulations and I anticipate changes taking place from around mid-2002. Part of this review is the proposal for a new filterability test for all diesel sold in New Zealand.

"These actions should give New Zealanders confidence that a similar problem with diesel fuel is highly unlikely to recur."