Large SUV · 1998–2018 cars

Mercedes-Benz M-Class reliability

The Mercedes-Benz M-Class fails 27% of first MOT tests, 29% fewer MOT fails than the average car its age and mileage, based on 136,678 DVSA MOT tests from 2022 to 2024.

Better than averageReliability score 76/100#15 of 30 large suvs

Checking a Mercedes-Benz M-Class before you buy?

first-time MOT fail rate (all cars: 28.4%): 27%; first-time MOT fail rate (all cars: 28.4%)
fails than cars of the same age and mileage: 29% fewer; fails than cars of the same age and mileage
MOT tests analysed, 2022 to 2024: 136,678; MOT tests analysed, 2022 to 2024
typical miles a year, from MOT readings: 9,100; typical miles a year, from MOT readings

MOT fail rate by age

How the Mercedes-Benz M-Class ages

Each point is the share of Mercedes-Benz M-Classs of that age that failed their MOT first time, against all cars of the same age.

Mercedes-Benz M-ClassAll cars

Mercedes-Benz M-Class first-time MOT fail rate by age
Age at MOT (years)	Mercedes-Benz M-Class	All cars
6	13.3%	19.1%
7	15.7%	22.1%
8	17%	25.5%
9	17.2%	28.8%
10	19.2%	31.8%
11	22.3%	34.6%
12	28%	37.3%
13	30.2%	39.5%
14	31.8%	41.1%
15	31.4%	42.3%
16	32.6%	42.9%
17	35.7%	43.4%
18	38.4%	43.5%
19	40.8%	43.4%
20	41%	42.8%
21	38.8%	41.4%
22	38%	40.6%
23	38.4%	38.9%
24	38.2%	37.1%

By year

The best and worst Mercedes-Benz M-Class years

2013 cars come out best and 2000 cars worst, once age and mileage are taken into account.

Mercedes-Benz M-Class MOT results by year of first registration
First registered	Tests	Fail rate	Against same-age cars	Typical mileage
2015 M-Class	12,510	15.3%	40% fewer fails	68,964
2014 M-Class	15,254	17.3%	41% fewer fails	78,847
2013 M-Class	16,986	17.4%	47% fewer fails	88,861
2012 M-Class	10,635	20%	43% fewer fails	93,097
2011 M-Class	10,776	27.9%	28% fewer fails	102,020
2010 M-Class	10,882	29.7%	28% fewer fails	110,602
2009 M-Class	8,624	30.7%	28% fewer fails	116,169
2008 M-Class	9,856	32%	28% fewer fails	122,580
2007 M-Class	9,582	32.5%	27% fewer fails	126,951
2006 M-Class	8,132	32%	29% fewer fails	130,176
2005 M-Class	4,367	39.8%	12% fewer fails	128,168
2004 M-Class	5,768	42.3%	7% fewer fails	129,571
2003 M-Class	4,308	41.2%	9% fewer fails	129,583
2002 M-Class	3,932	38.4%	14% fewer fails	130,372
2001 M-Class	2,220	39.7%	9% fewer fails	133,591
2000 M-Class	1,743	40%	6% fewer fails	132,730
1999	965	40.8%	0% fewer fails	130,378

Common problems

What fails most on a Mercedes-Benz M-Class

Failures by area, against cars of the same age and mileage.

Fail rate by area

Lights and electrics12.1%29% below avg
Brakes7.9%23% below avg
Suspension7.3%50% below avg
Tyres5%32% below avg
Exhaust, emissions and leaks3.8%26% below avg
Body, chassis and structure3%51% below avg
Windscreen, wipers and mirrors2.8%52% below avg
Steering2%37% below avg
Seat belts and airbags1.3%27% below avg

Average for cars of the same age and mileage

Top MOT failures

1
Coil spring fractured or broken 3.78% of tests
A broken coil spring can leave the car sitting low or unstable, so it must be replaced before driving.
2
Position lamp not working 2.47% of tests
A failed position lamp makes the car harder to see in poor light and is illegal, so it must be repaired.
3
Stop lamp not working 2.31% of tests
A failed stop lamp means drivers behind cannot see when you brake, a safety risk that must be fixed.
4
Tyre tread below 1.6mm 1.59% of tests
Tread below 1.6mm is illegal and reduces grip in wet conditions, so the tyre must be replaced.
5
Rigid brake pipe excessively corroded 1.46% of tests
Badly corroded brake pipes can leak or fail, which can cause a loss of braking, so repair is urgent.
6
Brake pads worn below 1.5mm 1.19% of tests
Pads worn below 1.5mm lose stopping power and can damage discs, so replacement is needed before the car is driven.
7
Tyre ply or cords exposed 1.17% of tests
Exposed ply or cords can let the tyre fail suddenly, so the tyre must be replaced before the car is driven.
8
Diesel engine warning light faulty 1.16% of tests
A lit or non-working engine warning light can hide faults, so diagnosis is needed before buying.

Most common advisories

Not a fail yet, but worth pricing in: these show up on a Mercedes-Benz M-Class's MOT certificate most often.

Tyre worn close to legal limit13.98%
Engine oil leak, not excessive11.7%
Brake pipes corroded and greasy8.5%
Brake pads wearing thin5.75%
Brake disc pitted or scored5.02%
Tyre slightly damaged or cracking3.07%

Before you buy

What to check on a used Mercedes-Benz M-Class

1
Coil spring fractured or broken
A broken coil spring can leave the car sitting low or unstable, so it must be replaced before driving.
2
Position lamp not working
A failed position lamp makes the car harder to see in poor light and is illegal, so it must be repaired.
3
Stop lamp not working
A failed stop lamp means drivers behind cannot see when you brake, a safety risk that must be fixed.
4
Tyre tread below 1.6mm
Tread below 1.6mm is illegal and reduces grip in wet conditions, so the tyre must be replaced.
5
Every MOT since new
Look for the faults above coming back year after year: it shows how the car has been looked after.
6
The mileage record
A typical Mercedes-Benz M-Class covers about 9,100 miles a year. A big gap or a drop between MOTs is a warning sign.
7
Finance, stolen and write-off
The records the MOT can't show. A Full Check (£9.99) covers all three before you hand over any money.

Fuel types tested

Diesel91.1%
Petrol8.8%
LPG0.2%
Other0%

Most common colours

Black, Silver, White, Blue, Grey

Average engine size: 2.9 litres.

Compare

How the Mercedes-Benz M-Class compares with its rivals

Mercedes-Benz M-Class against similar models
Model	Fail rate	Against same-age cars
Porsche Cayenne	13.8%	52% fewer MOT fails than the average car its age
Lexus RX	19.2%	43% fewer MOT fails than the average car its age
Audi Q7	16.8%	41% fewer MOT fails than the average car its age
Mercedes-Benz M-Class	27%	29% fewer MOT fails than the average car its age
Volkswagen Touareg	22.5%	26% fewer MOT fails than the average car its age
Land Rover Range Rover Velar	13.7%	13% fewer MOT fails than the average car its age
Mitsubishi Shogun	33.1%	11% fewer MOT fails than the average car its age

Every large suv ranked in the large suv reliability index, or all Mercedes-Benz models.

Questions

Mercedes-Benz M-Class questions, answered

Is the Mercedes-Benz M-Class reliable?

On MOT results, the Mercedes-Benz M-Class is better than average: it fails 27% of first MOT tests, 29% fewer MOT fails than the average car its age and mileage. It ranks 15 of 30 large suv models in our index.

What fails most on a Mercedes-Benz M-Class MOT?

The most common MOT failures on the Mercedes-Benz M-Class are coil spring fractured or broken (3.78% of tests), position lamp not working (2.47% of tests), stop lamp not working (2.31% of tests). By area, lights and electrics fails 12.1% of its tests.

Which Mercedes-Benz M-Class year is the most reliable?

Among years with 1,000+ tests, 2013 cars do best (47% fewer MOT fails than the average car its age) and 2000 cars do worst (6% fewer MOT fails than the average car its age).

How many miles does a Mercedes-Benz M-Class do a year?

A typical Mercedes-Benz M-Class covers about 9,100 miles a year, from the mileage recorded at its MOTs. Check the car you're looking at against that with a free mileage check.

How do I check a Mercedes-Benz M-Class before I buy it?

Enter its registration for a free check of its MOT history, mileage, ULEZ status and tax. Before you pay, a Full Check (£9.99) shows outstanding finance, stolen and write-off records.

Source: DVSA anonymised MOT test results, 2022 to 2024, class 4 vehicles aged 3 to 25, normal tests only. How we compare like with like: our methodology.

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