Random post, but just in case anybody was wanting to know uk law on dB levels for cars,
Not long had my 3rd gen rex and word round the camp fire was that somebody on my street was moaning how loud my car was, thought I would do some searching on the tinter web to find out what exactly is the legal dB limit is on the uk roads. found the info on "Department For Transport" government page.
In a nut shell on page 29 of the document, the summary is stated that it does vary between types of vehicles however 90dB (A) is widely excepted.
link: http://www.dft.gov.uk/pgr/roads/environment/research/trlreportexhaustnoisetesting/pdf/trlreportexhaustnoisetesting.pdf
going to get the dB from work and test what mine is, so long as its below 90dB he can go f**k himself! lol
I don\'t think there is an exact value on it, I did ask Mazda main dealer about it and apparently there isn\'t although I do believe its up to the MOT tester to deam if its \'excessivly above standard\' or something like that, as it might be classed as defective if the exhaust doesn\'t silence anything.
90dB? I\'d be very surprised if its as quiet as that! Good luck :)
BTW, the law as stated in that paper is that "shall not after the date of manufacture be altered so as to increase the noise" - so anything louder than stock is technically illegal.
Also, there is a seperate offense which is entirely at the judgement of the police officer, that being "using the vehicle in a manner to create exessive noise" (e.g. revving the nuts off it on the street)
Find me a stock FC3S exhaust lol
I wouldn\'t worry about a db reading. If they made a complaint to the cops they would see if you were being a nuisance like revving the nuts off it in the street as Aubec said. The police won\'t be bothered if you drive in a \'normal\' fashion down the street onto your driveway. Then you can go tell your neighbour to jog on :wiggle
I had a call round by my local bobby after a noise nuisance compaint had been made to them.
long and short there is not a Db max\' level - the exhaust can\'t be modifed to make a louder noise ie. holes in it. but on a side note that, as said above, it\'s up to the police to determine weather the noise is a nuisence or not; i was asked when i used the car what for and why the noise at 2am (work nights and need lunch) the case was then dropped and heard nothing more, so i still shake his drinking glasses in his kitchen every morning at 06:20
there is a thread on FDUK about this - LINK (http://www.fduk.org/forum/showthread.php?t=22520&highlight=noise)
MOT wise, it will fail if "the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a standard silencer in average condition."
So, it is very open to interpretation...don\'t know if that\'s a good thing or not...
The exhaust on my RX8 is quite a bit louder than stock and it passes its MOT without issue. I guess it\'s pretty subjective.
Aparantly if the exhaust is louder than the standard factory fitment it is an MOT fail, but on the road there is no actual limit, it\'s just what the old bill determin to be too loud!
Jono