MOT results by fuel

Diesel car MOT pass rates: by age, by model and the failures typical of diesel cars

Diesel cars passed 69.6% of 27,548,909 MOT tests in 2023–2024 (DVSA data, 14,262,429 cars, average age 9.6 years). Against all cars of the same age and mileage they failed 3% less often. At 3 years old, their first MOT, 83.5% passed.

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Data to 2024-12-30 · Page updated 2026-09-28 · Publisher: 73 Auto

Initial pass rate: 69.6%; 27,548,909 tests, 2023–2024
Tests with a dangerous defect: 9.0%; 1.00× cars of the same age and mileage
Models ranked: 302; at least 5,000 tests each

Diesel cars’ pass rate by age, against other fuels

Diesel cars had the higher pass rate at 1 of 18 ages from 3 to 20. By 20 years old 55.9% passed. Other fuels combine the remaining petrol, diesel, hybrid and electric cars, and differ in mileage and use.

MOT initial pass rate by age: diesel cars and all other fuels
Age	Tests	Diesel	Other fuels
3 years	1,095,176	83.5%	88.4%
4 years	1,528,072	82.9%	86.5%
5 years	1,858,119	81.3%	84.1%
6 years	2,313,812	79.0%	81.4%
7 years	2,639,873	76.2%	78.6%
8 years	2,639,770	72.9%	75.3%
10 years	2,128,493	66.5%	68.5%
12 years	1,657,743	61.4%	63.1%
15 years	1,026,456	57.2%	57.3%
18 years	485,596	55.4%	56.4%
20 years	232,075	55.9%	57.2%

Failures typical of diesel cars

Items diesel cars fail on at least 1.5 times as often as all cars of the same age and mileage band (a clear difference, at least 300 failures).

MOT failure items much more common on diesel cars than on cars of the same age and mileage
Defect item	Tests failing	Share	vs all cars
Outline marker lamp: missing	334	0.001%	2.72×
Outline marker lamp: not working	7,985	0.029%	2.70×
Outline marker lamp: does not illuminate simultaneously with the position lamps	449	0.002%	2.39×
All outline marker lamps: not working	936	0.003%	2.37×
Load sensing valves: inoperative and ABS not fitted or inoperative	735	0.003%	2.08×
Intermediate drop arm: insecure	386	0.001%	2.06×
Drag link end: ball joint dust cover excessively damaged or deteriorated so that it no longer prevents the ingress of dirt	2,686	0.010%	2.06×
Load sensing valves: seized and ABS not fitted or inoperative	3,159	0.011%	2.03×
Steering box: has excessive movement between sector shaft and the drop arm	375	0.001%	2.00×
Master cylinder/servo mounting: prescribed area is excessively corroded	1,665	0.006%	1.98×
Pre 01/07/2008 Turbo: emissions exceed level of metered smoke for a turbo charged engine	14,924	0.054%	1.96×
Pre 01/07/2008 Turbo: emissions exceed manufacturer's specified limit	47,940	0.174%	1.96×

Failures diesel cars rarely have

MOT failure items much less common on diesel cars
Defect item	Tests failing	Share	vs all cars
Catalyst emissions: carbon monoxide content after 2nd fast idle exceeds manufacturer's specified limits	216	0.001%	0.00×
Catalyst emissions: Lambda reading after 2nd fast idle outside specified limits	577	0.002%	0.00×
Catalyst emissions: carbon monoxide content after 2nd fast idle exceeds default limits	165	0.001%	0.01×
Catalyst emissions: carbon monoxide content at idle exceeds default limits	79	0.000%	0.01×
Catalyst emissions: carbon monoxide content at idle exceeds manufacturer's specified limits	133	0.000%	0.01×
Catalyst emissions: hydrocarbon content after 2nd fast idle exceeds manufacturer's specified limits	111	0.000%	0.01×

Most common MOT failures on diesel cars

Most common MOT failure items on diesel cars
Defect item	Share of tests	vs all cars
Tread depth: tread depth below requirements of 1.6mm	2.80%	0.96×
Position lamp: not working	2.77%	0.91×
Coil spring: fractured or broken	2.71%	1.03×
Brake pads: less than 1.5 mm thick	2.30%	1.03×
Stop lamp: not working	1.90%	0.89×
Wipers: does not clear the windscreen effectively	1.90%	0.94×
Joints: constant velocity boot split or insecure, no longer prevents the ingress of dirt	1.86%	1.18×
Ball joint: ball joint excessively worn	1.66%	0.96×
Condition: has ply or cords exposed	1.64%	1.05×
Headlamp: not working on dipped beam	1.59%	0.92×

By area of the test

Compared with all cars of the same age and mileage, diesel cars fail most often on seat belts and airbags (1.05×) and least often on noise, emissions and leaks (0.86×). 13.8% of tests recorded a minor defect and 53.2% an advisory.

Diesel models with the fewest MOT failures for their age

1.00 = the failure rate of diesel cars of the same age and mileage band. Raw pass rates are shown too, but younger models naturally pass more often.

Diesel models ranked by MOT failures against diesel cars of the same age and mileage, lowest first
Model	Tests	Average age	Pass rate	Failures vs similar
Audi A8	18,668	9.8 yrs	86.9%	0.41×
Porsche Macan	17,329	7.1 yrs	87.8%	0.54×
Audi Q8	7,387	3.6 yrs	91.0%	0.54×
BMW 7 Series	26,014	9.4 yrs	83.2%	0.55×
Porsche Cayenne	25,602	9.1 yrs	83.3%	0.56×
Mercedes-Benz S-Class	38,634	9.5 yrs	82.6%	0.58×
Audi A7	30,069	7.8 yrs	83.8%	0.59×
Mercedes-Benz GL	6,588	11.3 yrs	78.6%	0.61×
BMW X6	27,637	8.4 yrs	82.5%	0.63×
Volkswagen T-Roc	24,129	3.8 yrs	89.7%	0.64×
BMW 6 Series	7,252	6.8 yrs	84.5%	0.64×
Audi Q7	93,941	8.3 yrs	81.8%	0.65×
Skoda Karoq	25,094	3.9 yrs	89.3%	0.65×
Audi Q5	165,904	7.4 yrs	82.8%	0.66×
BMW 5 Series	326,738	10.2 yrs	78.0%	0.66×
Audi A6	230,930	9.6 yrs	78.6%	0.66×
Jaguar XJ	24,671	10.6 yrs	79.1%	0.66×
Volvo S90	11,112	4.9 yrs	87.0%	0.67×
Skoda Kodiaq	32,059	4.2 yrs	88.0%	0.67×
Volvo XC40	22,943	3.8 yrs	88.8%	0.67×

Diesel models with the most MOT failures for their age

Diesel models ranked by MOT failures against diesel cars of the same age and mileage, highest first
Model	Tests	Average age	Pass rate	Failures vs similar
DS DS 3	18,479	6.7 yrs	61.0%	1.76×
Dacia Sandero	43,440	7.5 yrs	59.9%	1.66×
SsangYong Rodius	5,726	7.3 yrs	60.9%	1.63×
SsangYong Tivoli	6,223	6.0 yrs	69.6%	1.59×
Peugeot Horizon	14,508	6.8 yrs	69.5%	1.58×
Citroen DS3	73,189	10.2 yrs	49.0%	1.56×
Nissan NV200	45,447	8.9 yrs	53.9%	1.51×
Renault Clio	137,374	9.7 yrs	55.2%	1.50×
Mercedes-Benz Citan	40,057	6.2 yrs	61.3%	1.50×
DS DS4	7,167	6.8 yrs	67.6%	1.50×
SsangYong Korando	14,703	7.0 yrs	66.1%	1.49×
Peugeot Rifter	13,120	3.3 yrs	80.7%	1.47×
Hyundai i800	16,530	7.3 yrs	62.7%	1.44×
SsangYong Rexton	7,015	8.1 yrs	64.1%	1.43×
Renault Kangoo	85,956	10.7 yrs	51.8%	1.43×
Nissan Pulsar	13,048	7.3 yrs	65.4%	1.42×
Citroen Berlingo	355,006	9.1 yrs	58.4%	1.40×
Fiat Tipo	6,881	5.6 yrs	72.0%	1.40×
Toyota Proace	23,194	5.0 yrs	69.4%	1.39×
Nissan Juke	169,407	8.4 yrs	62.2%	1.39×

Other fuels

Petrol cars · 71.9% pass rate
Hybrid cars · 85.6% pass rate
Electric cars · 84.6% pass rate

Limitations

Official data: DVSA anonymised MOT results (2023–2024), class 4 initial tests, cars at least 2.5 years old; fuel is DVSA's recorded fuel type (plug-in and self-charging hybrids are grouped). 73 Auto analysis: comparisons apply national rates for each test's age and mileage band. MOT results reflect maintenance, mileage and use as well as design, so a model's rank is not a reliability rating.

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Where these figures come from

Anonymised MOT tests and results (2023 and 2024) — Driver and Vehicle Standards Agency (DVSA). Open Government Licence v3.0.

Figures labelled as 73 Auto estimates are our own analysis of these sources, set out in the methodology and data sources. To report a factual error, see corrections.