MOT question

[carmanmemoranda]

Thanks all. Hoping the answers I like the most are correct

For info.

I'm a current mot tester. Mottie is an ex tester.

 

[carmanmemoranda]

Had MOT done yesterday and, forgive me if I am not very good with numbers, but the limit of my diesel test is 1.30.
My "dirty" car has spat out 0.07.
I used 3 search engines and 1.30 seems to be a number a lot bigger than 0.07.
I find this strange.
Should I trust the internet?
Also, I asked my engineer friend and on top of his head he said my car is almost 95% cleaner than the limit set at factory (limit taken from chassis plate).
He's probably just making it up.
How come do I have to keep my car under a cover hoping for the emperor of Londinstan to fall?
View attachment 333027

Ever heard of the vwag emissions scandal ?

 

[chainsaw_masochist]

Had MOT done yesterday and, forgive me if I am not very good with numbers, but the limit of my diesel test is 1.30.
My "dirty" car has spat out 0.07.
I used 3 search engines and 1.30 seems to be a number a lot bigger than 0.07.
I find this strange.
Should I trust the internet?
Also, I asked my engineer friend and on top of his head he said my car is almost 95% cleaner than the limit set at factory (limit taken from chassis plate).
He's probably just making it up.
How come do I have to keep my car under a cover hoping for the emperor of Londinstan to fall?
View attachment 333027

I find this rather confusing. Is the 1.30 limit a value assigned to the vehicle's NOx emission? If so, your readings seem to be nearer to those of petrol (see below) - 0.07 is around 5.5% of 1.30. If that was genuine presumably you could claim your Euro 4 vehicle to be ULEZ compliant? Just one other concern: The list of readings seem to have been provided on what appears to be a supermarket receipt - is this what customers now have to accept. Usually all of the technical details were provided on a couple of sheets of A4.

Euro emissions standards | AA

Euro emissions standards were put in place to improve air quality and health. The Euro 6 standard imposes a reduction in exhaust emissions from car diesel engines. Get the full lowdown on the limits and the background to them...

www.theaa.com

Euro 4 (EC2005)​

January 2005 (January 2006)


Euro 4 (January 2005) and the later Euro 5 (September 2009) concentrated on cleaning up emissions from diesel cars, especially reducing particulate matter(PM) and oxides of nitrogen (NOx).


Some Euro 4 diesel cars were fitted with particulate filters.

Euro 4 emission limits (petrol)​ CO – 1.0 g/km HC – 0.10 g/km NOx – 0.08 PM – no limit Euro 4 emission limits (diesel)​ CO – 0.50 g/km HC+ NOx – 0.30 g/km NOx – 0.25 g/km PM – 0.025 g/km

 

[Burnerman]

Crazy that a brake lamp fault can be ignored, but the sound deadening blanket under the bonnet is crucial.....makes you wonder who dreamt this lot up.
Same applies to the rear screen wash / wipe- surely a safety item?
John

 

[Mottie]

I find this rather confusing. Is the 1.30 limit a value assigned to the vehicle's NOx emission? If so, your readings seem to be nearer to those of petrol (see below) - 0.07 is around 5.5% of 1.30. If that was genuine presumably you could claim your Euro 4 vehicle to be ULEZ compliant? Just one other concern: The list of readings seem to have been provided on what appears to be a supermarket receipt - is this what customers now have to accept. Usually all of the technical details were provided on a couple of sheets of A4.

Euro emissions standards | AA

Euro emissions standards were put in place to improve air quality and health. The Euro 6 standard imposes a reduction in exhaust emissions from car diesel engines. Get the full lowdown on the limits and the background to them...

www.theaa.com

Euro 4 (EC2005)​

January 2005 (January 2006)


Euro 4 (January 2005) and the later Euro 5 (September 2009) concentrated on cleaning up emissions from diesel cars, especially reducing particulate matter(PM) and oxides of nitrogen (NOx).


Some Euro 4 diesel cars were fitted with particulate filters.

Euro 4 emission limits (petrol)​ CO – 1.0 g/km HC – 0.10 g/km NOx – 0.08 PM – no limit Euro 4 emission limits (diesel)​ CO – 0.50 g/km HC+ NOx – 0.30 g/km NOx – 0.25 g/km PM – 0.025 g/km

Nothing to do with any of the emissions readings. All the diesel test does is measure the particles of smoke emitted. A petrol engine is tested with an emissions tester, a diesel engine is tested using a smoke meter.

 

[johnny2007]

I find this rather confusing. Is the 1.30 limit a value assigned to the vehicle's NOx emission? If so, your readings seem to be nearer to those of petrol (see below) - 0.07 is around 5.5% of 1.30. If that was genuine presumably you could claim your Euro 4 vehicle to be ULEZ compliant? Just one other concern: The list of readings seem to have been provided on what appears to be a supermarket receipt - is this what customers now have to accept. Usually all of the technical details were provided on a couple of sheets of A4.

Euro emissions standards | AA

Euro emissions standards were put in place to improve air quality and health. The Euro 6 standard imposes a reduction in exhaust emissions from car diesel engines. Get the full lowdown on the limits and the background to them...

www.theaa.com

Euro 4 (EC2005)​

January 2005 (January 2006)


Euro 4 (January 2005) and the later Euro 5 (September 2009) concentrated on cleaning up emissions from diesel cars, especially reducing particulate matter(PM) and oxides of nitrogen (NOx).


Some Euro 4 diesel cars were fitted with particulate filters.

Euro 4 emission limits (petrol)​ CO – 1.0 g/km HC – 0.10 g/km NOx – 0.08 PM – no limit Euro 4 emission limits (diesel)​ CO – 0.50 g/km HC+ NOx – 0.30 g/km NOx – 0.25 g/km PM – 0.025 g/km

Don't know, what I know is that 0.07 is 95% smaller than 1.30 and despite this the emperor of Londinstan keeps my car off the road.

 

[chainsaw_masochist]

Don't know, what I know is that 0.07 is 95% smaller than 1.30 and despite this the emperor of Londinstan keeps my car off the road.

Except he doesn't... 'cos you got it MOTd . Seriously, though, owners can challenge their vehicle's claimed non-compliance if they have legitimate emission readings. I do not suppose that this would apply to your motor as you have said (previously) it is rather powerful.

 

[carmanmemoranda]

Don't know, what I know is that 0.07 is 95% smaller than 1.30 and despite this the emperor of Londinstan keeps my car off the road.

It means that even with faults and a badly worn engine, it still has a good chance of getting through the emissions part of the mot test.

The test is set at a low bar

 

[Mottie]

Except he doesn't... 'cos you got it MOTd . Seriously, though, owners can challenge their vehicle's claimed non-compliance if they have legitimate emission readings. I do not suppose that this would apply to your motor as you have said (previously) it is rather powerful.

Power of the vehicle isn’t relevant for ULEZ. My mate has a 2003 Ferrari 360 and that is compliant. Mot testing doesn't test HC, PM or NOx emission readings for diesels. It just gives a smoke reading so is of no use for compliance purposes. Euro 4 and mot limits are not comparable.

 

[Mottie]

Same applies to the rear screen wash / wipe- surely a safety item?

All that’s required for the drivers rear view is a compulsory drivers door mirror and either a passenger door or a rear view mirror. Obviously in a van with no rear windows, a rear view mirror is not acceptable so must have a passenger door mirror.

 

[johnny2007]

It means that even with faults and a badly worn engine, it still has a good chance of getting through the emissions part of the mot test.

The test is set at a low bar

Car is perfect.
Engine is barely at the beginning of its life, see the mileage on that emission test.

 

[carmanmemoranda]

Car is perfect.
Engine is barely at the beginning of its life, see the mileage on that emission test.

I wasn't trying to imply otherwise.

But that engine could still pass the mot with considerable wear .

The bar is very low

 

[carmanmemoranda]

All that’s required for the drivers rear view is a compulsory drivers door mirror and either a passenger door or a rear view mirror. Obviously in a van with no rear windows, a rear view mirror is not acceptable so must have a passenger door mirror.

Haven't looked it up to check but I think that's changed recently.

All 3 mirrors needed in cars, not vans now.

 

[Mottie]

Haven't looked it up to check but I think that's changed recently.

All 3 mirrors needed in cars, not vans now.

So it has. For cars registered after 2010. I didn’t know that, shows how out of touch I am these days. I must keep up with the special notices. It came out in January last year!

 

[Avocet]

Had MOT done yesterday and, forgive me if I am not very good with numbers, but the limit of my diesel test is 1.30.
My "dirty" car has spat out 0.07.
I used 3 search engines and 1.30 seems to be a number a lot bigger than 0.07.
I find this strange.
Should I trust the internet?
Also, I asked my engineer friend and on top of his head he said my car is almost 95% cleaner than the limit set at factory (limit taken from chassis plate).
He's probably just making it up.
How come do I have to keep my car under a cover hoping for the emperor of Londinstan to fall?
View attachment 333027

This is a long and complex topic.

When your car is type approved, it has to do an emissions test. That's a long and complicated test, done on a rolling road, so that the engine is under load, and with very expensive equipment. Probably costs about £5k to do the test. They measure unburned hydrocarbons (HC), carbon monoxide (CO), oxides of nitrogen (NOx), particulates and carbon dioxide (CO2). Few cars, after about 5 years old, no matter how well-maintained, would be likely to pass their type approval emissions test again.

The MOT test, is a cheap & cheerful test, with a MUCH lower bar. (It has been said that if the type approval test is like checking for the presence of a grain of sand in a black bin bag, the MOT test is checking for a house brick in a bin bag)!

Your printout is (as others have said), the result of the diesel smoke test. The meter is looking for visible smoke particles and remember, the engine isn't under any real load at the time the test is done. The type approval test measures grammes per kilometre of particulates that come out of the tailpipe during the car is on the rolling road. (In fact, current type approval emissions tests are now down to counting the actual NUMBER of individual particles that come out per km, never mind the weight)! By the time there are enough particles of smoke for the smoke meter to "see", you would have massively failed a Euro 6 emissions type approval test. In fact, any diesel that is Euro 5 or later, should read "zero" on an MOT smoke meter, because the particulate filter should catch them.

The units for the smoke test, are a rather bizarre "per metre" unit. You obviously can't use the grammes per km units in an MOT emissions test, because the car doesn't cover any distance during the test. This makes the two numbers impossible to compare directly, but whilst your car is well within the limit for its age, that really just means the limit is an incredibly low bar. If you took it for a current type approval emissions test, you would break the gas analyser! (Well, you wouldn't, but you would clog its sampling system up within the first few hundred yards)!