Published: 28 March 2013
The annual LGV roadworthiness test is under plan to be simplified by VOSA by stopping measuring exhaust smoke opacity which will in turn reduce the need to jack up front axles to check wheel-play.
However, new testing techniques being developed on the Continent could soon catch out trucks that have had their engine management systems remapped.
Currently exhaust emissions checked during the annual test are only measured on smoke opacity, which is an approximate guide to the level of particulate.
With fewer than 0.5% of trucks failing their annual test because they breached the smoke opacity limit, VOSA plans to downgrade the smoke test to a visual check due to this.
The opacity meter will be used to check marginal cases that have a Reduced Pollution Certificate.
VOSA said that due to the presence of detector plates it is not always necessary to jack-up a truck’s steer axle to test for excessive wear in wheel bearings or steering pivots and bushes although they state that it might be required on some circumstances so they cannot eliminate jacking entirely.
However, despite this, a big change in testing is in the pipeline. The identification of more sophisticated emissions testing equipment that will either interface with vehicles’ on-board data or be capable of measuring both oxides of nitrogen (NOx) and particulate matter at the tailpipe.
Vosa said stricter emissions checks could cause problems for LGVs that have had their engine management systems remapped or chipped. These modifications can upset the delicate balance between NOx and particulates, leading to excessive NOx emissions beyond original type approval limits, which the new system would identify.
No date for ending either axle-jacking or smoke opacity testing has yet been fixed.