AUK – the exhaust emissions test for motorcycles and quads

Since April 1, 2006, motorcycles, light four-wheeled vehicles (quads) and three-wheeled vehicles (e.g. trikes) subject to registration must undergo exhaust emission testing if the vehicles were registered after January 1, 1989.

The exhaust emissions test on these vehicles, known as the AUK for short, is carried out as part of the periodic main inspection. The carbon monoxide (CO) content in the exhaust gas is measured. The target values specified by the vehicle manufacturer of the trikes, motorcycles and quads etc. must be observed. If the manufacturers have not defined any limit values, the legally defined maximum values apply. For vehicles with a regulated catalytic converter, this is 0.3% carbon monoxide; for vehicles without a regulated catalytic converter, the upper limit is 4.5%.

It is important to note that there is no special AUK sticker. The HU sticker, which is only issued with a positive emissions certificate, also confirms that the AUK has been carried out. In the event of an inspection, for example by the police, the valid sticker from the main inspection is also valid for the emissions test.

Noise measurement on motorized two-wheelers

A second innovation concerns the testing of stationary noise on motorized two-wheelers. In the event of abnormalities, a stationary noise measurement must be carried out in accordance with the new directive. Only the noise measurement values with a difference of no more than two decibels in three consecutive measurements are used. The highest of the three measured values is taken as the measurement result. Five decibels are deducted from the measurement result as a correction value (tolerances in the measuring devices, etc.). The limit values for the stationary noise measurement as part of the general inspection are entered in the vehicle registration certificate under number 30, in the newer registration certificates in field U1.