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New MoT test will clamp down on dirty diesels

Published 27 February 2018

Diesel cars will find it harder to pass the MoT from May 2018 when the Government introduces strict new rules on emissions and DPFs.  

From 20 May, any Euro5 diesel that emits visible smoke of any colour will automatically fail the MoT in 2018. Diesel particulate filters (commonly known as DPFs) will also face mandatory checks, with failures being issued if the tester finds evidence of removal or being tampered with.

>>>> Top 10 causes of MoT test failures

According to the Driver and Vehicle Standards Agency (DVSA) guidance document: 'an automatic failure will be issued if the DPF canister has been cut open and re-welded, unless the owner can provide documented evidence for a legitimate reason like a filter clean'.

The reverse light will be part of the MoT for the first time...Aftermarket high intensity discharge (HID) headlamps will also be banned

The DVSA's also introducing new defect categories, with test faults now being listed as Minor, Major or Dangerous. Any car that gets a Dangerous fault will fail and be deemed illegal to be driven on the road. A Major fault will also fail and be subject to a repair and retest. Minor defects will be considered along the same lines as advisories, allowing the vehicle to pass with the faults being noted to the MoT history.

The reverse light will be part of the MoT for the first time and must operate automatically when reverse gear is selected. Aftermarket high intensity discharge (HID) headlamps will also be banned, with owners required to convert their HID headlamps back to halogen.

Garage - Volvo (9)

RAC spokesman Simon Williams said: “While on the surface this change, which is part of an EU Directive due to come into force in May, seems like a sensible move we fear many motorists could end up being confused by the new categories which give an indication as to the seriousness of vehicle defects identified in an MoT test.

“Rather than MoT failures simply being black and white, the new system creates the potential for confusion as testers will have to make a judgement as to whether faults are Dangerous, Major or Minor. This will surely be open to interpretation which may lead to greater inconsistency from one test centre to another.”

The DVSA has also scrapped plans to extend the first MoT for new cars from three to four years. A Department for Transport (DfT) consultation in 2017 considered changing the period before the first test to four years, a move that was met with significant concern by HonestJohn.co.uk.

According to the DfT, most of those responding to the consultation were against the proposals on safety grounds, arguing that the savings to drivers - estimated at around £100 million a year - were outweighed by the risk to road users with the MoT test often highlighting upcoming issues with a vehicle. A public survey for DfT by Populus also showed fewer than half of people were in favour of the change.

Check your car's MOT history


Engineer Andy    on 28 February 2018

I think that the new MOT rules are a mixed bag - good that many dirty diesels will now be caught, but bad that the ambiguous nature of the 'MOT fail' criteria seems, to me at least, to be a 'green light' to less scrupulous MOT stations (especially those where there's a repair shop/dealership attached) to either fail more to get extra repair work (especially where its deemed 'dangerous' so you can't drive it to another garage) or be vulnerable to bribery to reduce items to non-failure ones (or suchlike).

I preferred the strict pass/fail way - it gives everyone a clear demarcation and can be better understood when disputes arise - now its all about the tester's jusgment, rather like judges at a sporting event where interpretation means a great deal.

GORDON ROBINSON    on 1 March 2018

Totally agree --- the pass/fail is the right way --- its an honest way to do business --- as soon as you open up the possibility of bribery we are mirroring other third world countries where bribery and corruption is a normal way to do business.

A.Ward    on 1 March 2018

I don`t agree that a car cannot be driven away if it fails an MOT. I take my car to a dealership for test but would NEVER leave it there for repair.The cost is far to high. I take my car down the road to a small repair chap who does a top class job for half the dealer price. He doesn`t do MOTs because he doesn`t have the room in his small garage.

John Gwynne    on 1 March 2018

And what happens in the case of a tester that doesn't carry out repairs, as in the case of local authority garages?

landynut    on 10 March 2018

i agree bought 1st new car 18 months later stopped dealer said its the brain needs re programing had it done 4 months approx later stopped took it to a little garage told cam and crank sensors out off sink he replaced them cost £97.02p car now 4 year old and still running never again will stick to old cars more reliable

landynut    on 10 March 2018

i dont agree neither it just an open check book for the dealers and the doggey test centres you drove the car down there ok so you should be ba able to drive it to garage or home for repair dirty diesels dirty eu rules

Model Flyer    on 1 March 2018

Just another example of out of touch bureaucrats interfering and passing confusing legislation . Pass, fail or advisory is perfectly adequate . i agree about smoking diesels as there are too many around but what about a petrol car that smokes a bit on over-run, are they going to fail ? is the DfT going to raise the price to cover the cost of their interfering ?

Peter Axworthy    on 1 March 2018

Why oh why try and fix something that doesn't need fixing. They introduced a system where we don't need to display a road tax disc telling us that it will save millions of pounds. Guess what! They lost millions in unpaid revenue in the first year. Who are these people?

Mel Holley    on 1 March 2018

On the current MOT a tester can mark an item 'DANGEROUS', and some do. I know, I have a recent MoT with this on it! Very pleased to see that aftermarket high intensity discharge (HID) headlamps will also be banned, with owners required to convert their HID headlamps back to halogen - this is a serious safety risk with drivers being dazzled by oncoming cars

Karen's kars    on 1 March 2018

Peter Axworthy the system did need attention, I get blinded by illegal HID regularly they strip the flesh of your eyes ,literaly and burn your optic nerves leaving spots for ages. Diesel particals are killing us and our kids, it has to stop. Nothing is perfect,but I think this is a step in the right direction

Zouk    on 1 March 2018

Some 'running lights' are so powerful as to cause dazzle and are situated in a similar position to fog lamps . These types of lights should be regulated to lower intensity and be located away from fog lamp locations.

Margaret Sullivan    on 1 March 2018

I live in Ireland where there is a very strict criteria for the NCT [MOT]. The testers are lethal as regards emissions, failing for the slightest puff of exhaust smoke [and this is on petrol cars]. I now drive a diesel car, much more economical and cheaper to tax. My last petrol car cost 636eu annually, the diesel 280eu annually. The NCT is 55eu annually for a 10 year old car and 55eu every two years for a car four years -ten years. It's only a money making racket. If we abolish diesel completely the whole nation will have to revert back to the bicycle as tax, insurance and petrol are too expensive in this country and who's to blame? The government of course.

landynut    on 10 March 2018

i agree goverment create a problem so we have to pay to bail them out again and again think a public member who seen life should run the country

Phil2961    on 2 March 2018

Don't you think that it's always the same in every area of working life that those who sit at the top of the tree introduce measures they believe to be a good idea without discussing issues with those who work on the shop floor actually doing the job day in day out in getting a better idea of what would and/or wouldn't work in the interest of everyone concerned.
I believe that if the cost of everything was to be drastically reduced, introducing a better way of recycling, then we wouldn't feel the need to keep everything till it falls apart before its replacement, and that goes for all items required in our daily lives.

MartyF    on 2 March 2018

Like many diesel car drivers who have their cars regularly maintained, I sense the ongoing persecution of the diesel driver. All the negative rhetoric spouted by the “diesel is killing us” brigade are just highlighting their naivety to realise what’s really happening here. Sheep being led by idiots.

aethelwulf    on 2 March 2018

So an advisory is now minor? What farce. Testers have always pointed out issues that are potentially going wrong before the next MOT. I had an advisory that my front brake discs were scored but the braking efficiency was not affected. Fine, they needed fixing but no insurance company could moan they could cause an accident. Very cheap fix on a Ford anyway which I did at once.

WSM    on 2 March 2018

A cynical view: The sale of pre-MoT test anti-smoke additives will rocket, and it seems likely that many vehicles will be "ok on the day" only. The real baddies won't give a tinker's curse, as they will continue to take the risk of using their vehicles without any insurance, road tax, and authentic number plates, let alone MoTs. If they ever get caught, what do they care? Assuming they ever bother to turn up at court, it would have proved to have been the cheaper option, and the money they saved will fund the purchase of another old banger to use until the next problem arises. For those that steal cars, it has even less relevance. Thus the law abiding citizen will continue to fund these rogues.

Steven Campbell    on 2 March 2018

I don't get the demonising of diesels either, ok maybe they do put out a bit more nitrogen (which I realise is a harmful thing) than a petrol but does the government really think it's more sensible to go for a petrol car that's less efficient and produces more CO2? simple case in point I have a 1.6 DCI Kadjar and to go to the equuivalent petrol means going for the 1.2 turbo petrol which though it has the same horsepower has less torque meaning it has to work harder or the 1.6 turbo petrol which still has less torque meaning it still has to work harder and is much sorer on fuel? Doesn't make a blind bit of sense to me. And if they're after people to buy electric cars they are too expensive don't have the range for my needs living in a rural area and despite the fact they may not produce emissions from the tailpipe, because they're heavier there's more emissions comes from their tyres and indeed the coal powered power station that supplies the electricity therefore not making them as "green" as everyone thinks they are.

On another note, this whole "Oh it'll make cars more dangerous if the MOT goes from 3 to 4 years" is complete nonsense! I live in Northern Ireland where cars don't need an MOT until 4 years old and they are no less safe than the same cars on mainland GB so to suggest them is frankly silly.

RodK    on 5 March 2018

I lived in N Ireland for 11 years and the mot system there is excellent. No test until the car is 4 is basic common sense. Maybe introduce a mileage cap would be an added precaution. Independent mot stations is a obvious no brainer. Bring the system to England I say

sherwenator    on 2 March 2018

i agree ,,,why fix something that isnt broken,,,,pass or fail works ok now
where do people stand on modified parts added to cars for performance such as engine upgrades and piggyback ecus?????

Robbutt    on 2 March 2018

I would suggest buying shares in a company making brake disc's as it seems that the thickness of the disc will be subject to the new test. I have had my brake pads advised over the last couple of years and when I pulled them out to be changed there was 9mm left on them!! a license to print money as when the discs are replaced they will replace the pads. I think this is just to keep the independant garage trade going as they seem to be suffering due to the high take up of pcp's.

mickey2ties    on 3 March 2018

For anyone interested, a draft version of the new MOT inspection manual can be viewed on the gov.uk website using the following link:


As far as I can see, it's at least as prescriptive as its predecessor - for each component to be inspected, what constitutes a "dangerous", "major" or "minor" defect is fairly precisely defined. The room for the tester to use "judgment and experience" is actually rather limited and, should the tester determine that a defect is dangerous, it has to be clearly explained to the person presenting the vehicle for inspection. Defects resulting in a fail may now fall into two categories, "major" and "dangerous" but a fail has always meant that the vehicle can't legally be used on the road, whereas now, if the defect is rated as "major" but not immediately prone to failure, you at least get the opportunity to have it repaired and submit your vehicle for a retest.

I wonder also how many people are aware that advisories are currently only "best practice", not mandatory? It puts those pristine MOT histories into rather a different light if hitherto the garnishing of your certificate has been purely at the whim of the tester. Under the new rules reporting minor defects will be mandatory, so turning a blind eye will be a much riskier business!

Bill Biggs    on 4 March 2018

I have concerns regarding the new Engine Malfunction Illustration Light (MIL) 'Pass/Fail' requirement. The MAIL can illuminate for a number of reasons which don't effect the road wordiness of the vehicle. Some Vehicles fitted with after market Bi- Fuel ( e.g. LPG) , due to vehicle software not automatically recognizing BI:fuel system electrics, can cause the MIL to illuminate _ No roads worthy / safely issue, just an dashboard illumination issue which a simple fault coder reader can reset for a short period ( fault code reader should identify any actual faults requiring further investigation) . New MOT should commence with ' Plug into vehicle Service/ Fault Code system, Start Vehicle, Check Service & Fault Codes, Record Results , Clear Codes, re-start vehicle_ No MIL Illumination ( i.e. No Fault Codes) 'Pass', this process would not only illuminate any false MIL readings, but also highlighted any true Engine Malfunctions. This needs issue needs correcting NOW! Before MOT stations incorrectly fail perfectly serviceable, Road Worthy and thus Safe Bi-Fuel vehicles- A conversion process championed, inclusive ( at that time) of
conversion Grants, by a previous HM Government.

landynut    on 10 March 2018

Dont tell em that the m.o.t fee will go up tp £150 £140.00 for the goverment to give to the eu

   on 5 March 2018

Trust this will also apply to all the buses in city centres which are far more polluting or do they get an exemption because it would cost Gov't/Local Auths money?

D,Leach    on 5 March 2018

No problem, We have the vote, ,so the answer is, ,vote out the current set of feck witt's and replace them the previous set of feck witt's, ,on the understanding of course that they get rid of Jeremy Corbitz and replace him with Gorden Brown, so then working on the fact that these people are always in the right we should get 4 years of get rid of your nasty petrol cars and get yourself a less polluting diesel, ,oh hang on we did that a few years ago, ,so, who's to blame, ,dont tell me both parties have been advised by the same set of experts, who somehow forgot that they got it horribly wrong last time, ,no prob's we now have green electric cars, ,now let me think , how are they powered, oh yes, power stations, ,hang on, did'nt they start blowing these things up cos they were polluting the atmosphere. ,what was it, could'nt up a piz in brewery in run a,

landynut    on 10 March 2018

cant we just bill the goverment then for fraudulent missleading off the public set off skid marks all off them p:s dont forget the 50.000 pound pay packet for the crap information

Filpot51    on 7 March 2018

Engine Management Light. I understand that the draft regulations will demand that the EML lights up when the ignition is switched on but goes out when the engine starts. This could cause thousands of lpg converted vehicles to fail unnecessarily as the EML often stays on with such vehicles. Surely it makes more sense to continue to rely on the actual emissions readings particularly as LPG vehicles typically produce less emissions.

Chris James    on 8 March 2018

Standby by for the glut of £0.99 Ebay specials from Aliexpress to replicate the EML light switching on/off after a timed period to pass the MOT even when there is a fault!. A large chunk of the commercial market resorted to similar 'Emulators' over several years on Adblue systems, simply because they aren't reliable or worse still - don't work properly. In light of the MOT changes there is a huge niche for this EML emulator market now and I can see it being filled very rapidly, if not already. These changes will solve nothing, other than to boost the Chinese Electronics market.

As usual the jolly boys in Government go after the end user in the form of tougher MOT's, instead of forcing the manufacturers to come up with something reliable so customers wouldn't have to resort to removing parts of their vehicle or fitting Electronics to fool the system into bypassing the system and working properly in the first place!.

Suffice to say that a large number of EML light faults on modern cars are caused by emissions control 'bolt ons' or the sensors failing (which monitor those bolt on's), and this will continue to be a problem whilst we let Tree Huggers design cars instead of Engineers. In some cases, i've read that even the dealers have issues finding long term solutions to some EML triggers, and customers often have to go back several times until they figure out why the Computer continues to say no. If the dealers can't solve it, then the customers eventually will, with a £0.99 black box!.

Captain-Cretin    on 12 March 2018

I used to own an Audi with a bulb warning system fault. The ONLY way to get the dead bulb warning to go out was to remove both bulbs!!

I am also worried about the new faults system; one MOT station near me ALWAYS gives out fake advisories to drum up business; every year for 5 years they told me my brake pads needed changing, and my sister got caught out by a VW one saying she needed new front disks 3 years running - which she paid for but they NEVER fitted.

Year 4 I noticed the same advisory again, queried it with her and then got an independent to check the disks - still the factory originals. So that is somewhere in the region of £1500 they conned out of her.

It reached the point YEARS ago, where I stay at the MOT station and watch them, to keep them honest; I even caught one guy crow-barring a front brake cailper, to make the test show the brake balance out of tolerance

Edited by Captain-Cretin on 12/03/2018 at 08:20

bluezzr1100    6 days ago

I doubt it will make much difference. Those who operate illegally will continue so to do. Have you ever tried reporting a vehicle with no Tax or MOT. No one is interested, least of all the police.

Dodgy garages will continue to behave without scruples and good ones will continue to be just that.

Smoky diesels and painfully bright headlamps will continue unabated because plod is nowhere to be seen. The thin blue line is about 5 microns across these days so why do any of us bother to behave within the law?

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