Is the stock 2018 Mustang GT active exhaust technically illegal in the UK?

[Manders Mustang]

How certain are we of this 'loophole'. Is there any write up discussing the technicals etc or is it just hearsay? I've seen a few sources say it simply can't be louder than what came from the factory.

yeah the stock exhaust can't be louder.... but if you change the exhaust, it's not a change to the stock exhaust. Now if you put axle backs on the car, then you're in for a treat.


Liklihood of ever, EVER being pulled in a MOT or on the street for this is so low you may as well gamble your life savings on the lottery because it's better odds than this.


@SteveS i was lead to believe full system rather than catback (So for V8's headers with CATs, and Catback, for EB's downpipe with CATs and Catback aka 'Turboback') as anything on that pipeline is technically the exhaust.

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[Gregs24]

The standard OEM exhaust is type approved and hence legal. Look at your V5 and you will see the official figures for the test.

 

[Stuart0202]

Funnily enough, the police in my area had a crackdown about 2 years ago and pulled plenty of people for their exhausts. All were Corsa's and Fiesta's though.
Was more the cars that were obviously not that loud from the factory

 

[Manders Mustang]

Funnily enough, the police in my area had a crackdown about 2 years ago and pulled plenty of people for their exhausts. All were Corsa's and Fiesta's though.
Was more the cars that were obviously not that loud from the factory

and that's the kicker, a mustang you don't look at and say "that shouldn't sound like that"

 

[drewzh]

and that's the kicker, a mustang you don't look at and say "that shouldn't sound like that"

You make a good point I think there's multiple points to this thread.

1) It seems that even from the factory, yes the Mustang is capable of going above what police consider to be 'illegal', even if it's type approved. This point still seems unclear - some sources (i.e, police official docs and vehicle certification agencies) don't cite "type" and only state decibels; which is contrary to the whole "type" approved argument.
2) As long as it's on the car from factory, technically it's nothing to worry about, even if the police think so; as what can you do? There's no other options for the car. I guess an argument could be made about revving the engine too high perhaps? Do we have laws against this? Probably another grey area!
3) The chance of getting pulled over in a Mustang, which iconically sounds far beefier than the average UK road car, is quite minimal and from what I'm reading - It doesn't seem to be a common scenario.

For me at least, hearing what everyone has to say, has settled some of my worries at least. My 18 GT in due to have it's H pipe fitted tomorrow - probably technically illegal at higher revs I know, but as I don't intent to go crazy (I'm in my thirties and not looking to needlessly show off), I think I'm comfortable enough to go ahead and not worry too much. It seems, when bound to the decibel limits the police and various agencies cite - the factory Mustang GT exhaust is already way above what's technically aloud.

 

[hinch]

nobodies ever bothered with mine usually when i pull up next to a bacon wagon they just want to compliment me on the car and say "that sounds nice" rather than do anything about it i don't think theres many out there quite as loud as mine perhaps sheps maybe

 

[Gregs24]

It would be handy if an 18MY owner could check on their V5 to see what the db values are, also a pre 18MY for comparison

I can't imagine anybody ever puts a quieter aftermarket exhaust on but the situation could occur where an aftermarket exhaust equipped non Mustang car, that is quieter than a Mustang, could be illegal but the Mustang as stock be fine.

 

[W111BOB]

nobodies ever bothered with mine usually when i pull up next to a bacon wagon they just want to compliment me on the car and say "that sounds nice" rather than do anything about it i don't think theres many out there quite as loud as mine perhaps sheps maybe

mines nowhere near as beefy as yours Dave... but I had an officer walk over the car park in lakeside today and he told me that he loved the sound of my exhaust... even asked me to ",give it a rev"... big smiles and he walked away smiling.....

 

[hinch]

mines nowhere near as beefy as yours Dave... but I had an officer walk over the car park in lakeside today and he told me that he loved the sound of my exhaust... even asked me to ",give it a rev"... big smiles and he walked away smiling.....

that seems to be the general response of everyone i've met (apart from the grumpy old .... nextdoor )

 

[500PLUS]

Got an x pipe on my 18
It is loud

 

[drewzh]

But officer, Mustang6G members told me it would be fine!

 

[500PLUS]

Be careful right side connector into exhaust valve motor is very close to body seam
Exhaust stretches a lot when hot
Mine hit

 

[drewzh]

Be careful right side connector into exhaust valve motor is very close to body seam
Exhaust stretches a lot when hot
Mine hit

How do you mean? Everything seemed to hang properly and I didn't detect any issues with the servos touching anything, though you're making me want to get back under and check now! If everything hung as per stock, surely it should be fine?

 

[Adester]

yeah the stock exhaust can't be louder.... but if you change the exhaust, it's not a change to the stock exhaust. Now if you put axle backs on the car, then you're in for a treat.

It's interesting that the article from the Police states "must not be altered or replaced in a manner which increases the noise". This would seem to imply that the exhaust can't legally be replaced with a louder version.

I know this is a bit of a moot point, as most Police officers in my experience like the sound a Mustang, but it's printed there in black and white!

 

[W111BOB]

how many prosecutions on this then? I am guessing - none

I totally agree - most police officers like the sound of the Mustang - and only a real weirdo psycho officer would actually charge you for it!

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