speaking as a car tester no we dont use noise meters,used to do rallying and the decibel limit(checked by the local authority as some stages were on public roads)was 105.5 db @ 500rpm.we as testers get told that as long as its got a box of some sort we essentially have to pass it unless its at wake the neighbours sorta level,we dont get a set noise limit its purely subjective and the opinion of the tester concerned.in real world use most vehicles that still have a cat/turbo wont be loud enuff for us to fail,most of the anti social ones probably werent fitted at test or more likely have a-lets say-sympathetic one,cheats?theres loads ranging from switchable power levels to exhaust cutouts.as you can see the rules such as they are can be misused/widely interpreted.revving engines to the red line during the test?(im assuming petrol here)we are responsible for any damage/costs caused by such actions so unless youre volunteering to come round and buy em a new engine…
