[Traum]

So I sent an email to CVSE yesterday to ask about measurement procedures for exhaust noise:

I have a question regarding maximum allowable exhaust noise levels for light vehicles in terms of compliance with the Motor Vehicle Act (MVA) and CVSE light vehicle inspection regulations. I was unfortunately not able to find a definitive answer after reviewing both the MVA and the CVSE inspection manual, so I am hoping you could clarify that for me.

In Division 7 - Other Equipment, under Schedule 27 regarding Vehicle Noise, the MVA only states that when tested in an inspection station, the vehicle engine, any auxiliary engine and exhaust level from a light duty vehicle must not exceed a maximum allowable sound pressure level of 83 DBA. However, there is no description on what the measuring procedure or standards at which the sound reading is obtained from. Similarly, in the CVSE inspection manual for light vehicles, under Section 1 - Power Train, item o) on noise emissions, it only states that noise level must be confirmed with decibel meter for any vehicle with non-OEM, modified, or altered exhaust system. No measuring procedure or standards is described in regards to how the sound reading is collected.

As most people are aware, exhaust noise levels vary depending on the engine RPM (among other factors). Measured readings can also vary tremendously, depending on how the reading is obtained. For example, distance from the sound source (ie. muffler), the direction of the decibel meter in relation to the exhaust opening, etc. can all change the reading by quite a bit.

Is there a standardized procedure at which the reading is obtained when an inspection is performed at a CVSE-authorized inspection facility?

Thank you for your assistance.

The following reply came back from a manager of the Provincial Vehicle Inspections & Standards Program:

Thanks for taking the time to send your question. At this time there is no standardized noise emission test for BC. The legislated requirements to determine excessive noise levels are prescribed through the opinion of an inspector in Motor Vehicle Act Regulation division 7. The referenced decibel levels in division 7 are only applicable when tested in provincial inspection stations which have not been a part of the inspection program for some time. All vehicle inspections are now conducted at designated inspection facilities. It is expected that authorized inspectors will confirm their opinion of excessive noise – or not excessive noise – with the use of a decibel meter as mentioned below.

I hope this provides the information you are looking for.

I really shouldn't be surprised. But well...