Commercial vehicles unlikely to be drawn into VW emissions scandal, say experts

Experts believe the scandal over emissions testing and Volkswagen, (VW) cars will not spread to the commercial vehicle sector because Euro-6 legislation significantly tightened up differences observed in laboratory and real world conditions.

As the car manufacturer faced growing accusations that it attempted to cheat emissions tests in America and possibly further afield, a report into the performance of Euro-6 HGVs found that the legislation has been overhauled to correct differences in NOx level observations.

The Transport for London study published earlier this month said NOx levels had previously been “much greater than the type-approval legislation would suggest might be expected. This phenomenon has been widely reported for Euro-5 heavy duty vehicles”.

It added: “In drafting the legislation for Euro-6, steps have been taken by the European Commission to correct this problem. These new measures seem, at this early stage, to be effective in controlling ‘off-cycle emissions’ much more successfully than before.”

“However, they still do not guarantee universal compliance with the standard under all driving conditions.”

No evidence to suggest vans effected

Tim Barlow, principal consultant at the Transport Research Laboratory, said vans were tested in the same way as cars and that it was possible similar issues could emerge: “However, there is currently no evidence to suggest that it is,” he added.

“Heavy good vehicles only test the engine unit, complete with fuel system, engine control system and any emissions control systems, on an engine test bed. The old test was subject to abuse, known as cycle beating - in other words, controlling the emissions just for specific test points.

“But this test was revised and replaced when Euro-3 was introduced, with a new transient test cycle added. The latest Euro-6 vehicles are tested over a new world-harmonised transient test cycle, which should reduce the opportunities for cycle beating.”

Chris Snelling, FTA’s head of national and regional policy, said: “Before the scandal broke, cars were going through the Euro-6 system and not matching that performance on the roads. But for HGVs it is much better, much more compliant with Euro-6 tests.

“There was never a suggestion anyone faked their way through the tests, it was just the way they [the tests] were designed. I think we can be hopeful and reasonably confident we don’t face the same problem in the market.”

Euro-6 delivering results

RHA policy director Jack Semple said: "It's very, very relevant that TfL describes Euro-6 heavy diesel trucks and buses as ultra clean with specific reference to NOx. The test cycle for Euro-6 lorries was changed from what it was before. Not only were the output levels reduced but the test cycle was also more demanding, which means that in practical operations the lorries and producing the low emissions that the test cycle was designed to get them to.

"Up to and including Euro-5, the allegation is that the test cycle wasn't replicated in practical operations in cities. Euro-6 appears to be delivering what it was supposed to be delivering."

A spokesman for the SMMT was reluctant to comment on the truck market, but he said it had lobbied for a change in testing of vehicles to reflect "more real world conditions", adding: "It's no secret that there's a discrepancy between what comes out of the lab tests and what comes out in driving. There's always been that discrepancy but it doesn't do us any favours."

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