Guide: Exhaust noise and the Law

[Norledge]

For most passenger vehicles with not more than 9 seats, the noise limit is
80 decibels (see Regulations 54 - 59 of the The Road Vehicles (Construction
and Use) Regulations 1986).

There are a number of exceptions, qualifications and restrictions and I
suggest you take a look at the legislation.

The noise is measured by using a 'sound level meter' of the type described
in Publication No. 179 of the International Electrotechnical Commission, or
a 'sound level meter' complying with the specifications of the British
Standard Number BS 5969:1981 which came into effect on 29th May 1981.

Generally, the offence that a person would be charged with is that of
'using a motor vehicle with an altered exhaust' or 'using a motor vehicle
with an inefficient exhaust/silencer'.

Both offences contravene section 42 of the Road Traffic Act 1988 as they
breach construction and use regulations.

Either offence can be dealt with by way of a £30 fixed penalty ticket or,
if the case went to court, a fine of up to £1,000.

[Jonny81191]

Hmm. Does carrying my backbox round in the boot cos it fell off constitute "an altered exhaust"?

[PUGNUT_XS]

HMMMMM think my exhaust is slightly over that DOH !!!!!!!!

Is that 80 decibels at idle?

Got to be a loophole

[Norledge]

Conditions specified in paragraph I.3 of the Annex to Community Directive 77/212
Method specified in paragraph I.4.1 of the Annex to Community Directive 77/212
Requirements specified in heading II of the Annex to Community Directive 77/212 (except paragraphs II.2 and II.5).

I need to find this annex to Community Directive to find out the answer...

---

Found it... http://eur-lex.europa.eu/LexUriServ/LexU...57:EN:HTML

From what I can tell...

At least two measurements shall be made on each side of the vehicle. Preliminary measurements may be made for adjustment purposes but shall be disregarded.

An engine speed equal to three-quarters of the maximum engine speed permitted by the governor

The third gear in the gearbox must be engaged if the box has more than four gears

Measurements shall be made at point X (shown in Figure 2) at a distance of 7 metres from the nearest surface of the vehicle. The microphone shall be situated 1.2 metres above ground level.

So 3rd gear, 3/4 revs, 7m away... How the chuff do they measure that on the road!?

[4WayDiablo]

So my gov will let my Dtub rev to gone 6k. I could blag it to the redline. 7m away even better
Would have to be very loud to fail

[Ruan]

Conditions specified in paragraph I.3 of the Annex to Community Directive 77/212
Method specified in paragraph I.4.1 of the Annex to Community Directive 77/212
Requirements specified in heading II of the Annex to Community Directive 77/212 (except paragraphs II.2 and II.5).

I need to find this annex to Community Directive to find out the answer...

---

Found it... http://eur-lex.europa.eu/LexUriServ/LexU...57:EN:HTML

From what I can tell...

At least two measurements shall be made on each side of the vehicle. Preliminary measurements may be made for adjustment purposes but shall be disregarded.

An engine speed equal to three-quarters of the maximum engine speed permitted by the governor

The third gear in the gearbox must be engaged if the box has more than four gears

Measurements shall be made at point X (shown in Figure 2) at a distance of 7 metres from the nearest surface of the vehicle. The microphone shall be situated 1.2 metres above ground level.

So 3rd gear, 3/4 revs, 7m away... How the chuff do they measure that on the road!?

Run very fast behind...

Maybe this is why you rarely see people being done for loud pipes...

[c.gerrard]

I was concerned for mine to start with, but after going past a few police cars and even having one follow me for a bit the other day, I think I'm safe

[Jonny81191]

I was concerned for mine to start with, but after going past a few police cars and even having one follow me for a bit the other day, I think I'm safe

The thing with yours is the fact that it's so in your face, a 5" pipe on a 306 is huge!

So I guess if you're OK then there's nothing to worry about!

[Rich306]

Conditions specified in paragraph I.3 of the Annex to Community Directive 77/212
Method specified in paragraph I.4.1 of the Annex to Community Directive 77/212
Requirements specified in heading II of the Annex to Community Directive 77/212 (except paragraphs II.2 and II.5).

I need to find this annex to Community Directive to find out the answer...

---

Found it... http://eur-lex.europa.eu/LexUriServ/LexU...57:EN:HTML

From what I can tell...

At least two measurements shall be made on each side of the vehicle. Preliminary measurements may be made for adjustment purposes but shall be disregarded.

An engine speed equal to three-quarters of the maximum engine speed permitted by the governor

The third gear in the gearbox must be engaged if the box has more than four gears

Measurements shall be made at point X (shown in Figure 2) at a distance of 7 metres from the nearest surface of the vehicle. The microphone shall be situated 1.2 metres above ground level.

So 3rd gear, 3/4 revs, 7m away... How the chuff do they measure that on the road!?

I think the car would have to be taken to a garage rolling road.

[camoturd]

I can say I have had car that are well above 80 db easily had one at 110 had sound deaden car to be able to hear people talk in car