Pass rate
82.0%
Around average — 9.2 pts behind the 91.2% that cars this age and mileage manage.
Across 128 recorded tests.
Typical repair bill £37–£87
2021 Mercedes-Benz Cls MOT pass rate
- 2021
- 2 trims combined
- typical 27,004 mi
Most common fault
Tyres
46.8% of faults · 19.8% nationally
mostly tread below the limit, cuts and sidewall bulges.
Part only £55–£85 for Tyre has a tear. What fitting it takes →
1.1 pts down across model years — 3.0% in 2005, 1.9% in 2019.
Which year to buy
- Best 2018 86.3% pass
- Avoid 2009 75.6% pass
Across the 17 years on record, a spread of 10.7 points. See every year →
- First-attempt pass
- 78.5%
- Typical mileage
- 27k mi
The 2021 Mercedes-Benz Cls MOT pass rate is 82.0% of its MOT tests — 9.2 points behind what its age and mileage predict. Tyres is the biggest single reason it fails, at 46.8% of what testers record.
Check your postcode
MOT pass rates are national — type your postcode to see how Mercedes-Benz Cls does in your corner of the country.
Expert verdict
Tyres: 2.4× the national share
Tyres make up 46.8% of everything recorded on the 2021 Mercedes-Benz Cls, against 19.8% nationally — 27.0 points above. Check all four tyres yourself, including the inner shoulders, and look at the date stamp — a tyre can pass on tread and still be six years old.
- Falls short of its own age and mileage. Like-for-like, cars this age and mileage expect about 91.2%; this one manages 82.0% — 9.2 points below. Age is a fair excuse; this is not age.
- When it fails, it costs. Only 0% of this model’s typical repairs come in under £30 in parts — the failures here tend to be the kind that need a garage rather than a bulb.
Written from this page's own figures: fault shares against the national composition, the like-for-like pass rate, and the priced repair list. How these are worked out
Watching a Mercedes-Benz Cls? Get an email when these numbers change .
Every Mercedes-Benz Cls first registered in 2021 is combined here — 2 trim and body variants in total — so the sample is as large as the DVSA data allows.
How does the 2021 Mercedes-Benz Cls compare?
Cars of this age and mileage average 91.2%, so this figure is 9.2 points behind what its age and mileage predict. On a first attempt, before any retests, the figure drops to 78.5%. The median 2021 Mercedes-Benz Cls in this dataset had covered 27,004 mi.
78% of the tests on this vehicle ran on Diesel, which passed 80.0% of the time. Pass rates also shift with the test month: tests recorded October–March passed 82.7% of the time, April–September 81.1%.
The single most recorded failure item is "Fractured", noted on 9.38% of tests.
- 128 recorded tests behind this page.
- 82.0% overall pass rate, 78.5% on a first attempt.
- Across every year of the Mercedes-Benz Cls, the average is 81.2% — best year 2018 (86.3%), worst 2009 (75.6%).
Figures count every completed test on this vehicle-year in the dataset, including retests. See methodology for the exact definition.
This page's data
- Tests analysed
- 128
- Typical mileage (median)
- 27,004 mi
- Make and model
- Mercedes-Benz Cls
- Updated
- 2026-11-05
Source: DVSA anonymised MOT test data (2023–2025), OGL v3.0.
Top part to budget for
Wheel Hub Bearing Kit
Usually a DIY or independent-garage job.
Does mileage affect the Cls MOT pass rate?
Pass rate by odometer reading. Bar lengths start at 67% so small gaps stay visible.
Fuel type and reliability
Pass rate by fuel type. Diesel is the most common here (78% of tests).
Regional pass rates for the Cls
| Region | Tests | Pass rate |
|---|---|---|
| South East | 30 | 93.3% |
| West Midlands | 19 | 78.9% |
| East of England | 17 | 82.4% |
| London | 16 | 93.8% |
Regions come from the postcode area recorded at the test station. Areas on region borders are assigned to the region with the majority of their population.
What fails a 2021 Cls
Everything a tester recorded on this vehicle, grouped into the inspection sections that produced it. The notch on each bar is the national share, so you can see at a glance whether this car is unusual or just ordinary.
A test can record several items, so these percentages do not add up to 100%. The exact strings, with prices, are in the full DVSA record at the bottom of this page.
Before your test
Three checks worth doing on a 2021 Cls
These are not generic tips — they are the faults recorded most often on this exact model, rewritten as things you can check yourself. All three take about ten minutes and cost nothing.
-
Check the windscreen 3.1% of tests
“windscreen damaged”
Check the driver’s side of the screen within the swept area for chips and cracks; anything larger than 10mm in the driver’s central view is a fail. Most chips can be resin-repaired for far less than a new screen.
-
Check the suspension joints 1.6% of tests
“ball joint excessively worn”
With the car parked on level ground, rock the top of each front wheel in and out while someone watches the suspension arm. Clunks, or rubber boots split and greasy, are what testers record here.
-
Check the brakes 0.8% of tests
“brake pads less than 1.5 mm thick”
Look through the spokes of each wheel at the pad — less than 3mm of friction material, or a lip on the disc edge, is the usual failure. Check the handbrake holds on a slope with a few clicks, not at the top of its travel.
Shares are the proportion of tests on this vehicle that recorded the item, so they overlap: one test can record several.
What it costs to get a 2021 Cls through its MOT
Across the 10 items that are recorded most often on this model, the average repair comes to £37–£87 — and 0% of those repairs are parts that cost under £30.
- Average repair across the 10 common items
- £37–£87
- Cheapest common item: ball joint excessively worn
- £18–£45
- Dearest common item: windscreen damaged
- £80–£200
- Common items a careful owner can do at home
- 90%
- Repairs that still cost under £30
- 0%
Estimates from typical UK parts prices, weighted by how often each item appears in 128 MOT tests on this vehicle. They exclude diagnostics, retest fees and garage labour where the part is a DIY fit, and they are not figures from the DVSA dataset. Older and higher-mileage examples cost more than the average. How these estimates are built → · All MOT repair costs → · Cheapest cars to put through a test →
Every year of the Cls, side by side
17 model years on record, from 2005 to 2021. Across them the pass rate runs from 75.6% to 86.3% — a spread of 10.7 points. The bar under each year is the item that failed it most often.
- 2005 79.9% ball joint excessively worn
- 2006 78.6% ball joint excessively worn
- 2007 77.4% ball joint excessively worn
- 2008 77.2% ball joint excessively worn
- 2009 75.6% ball joint excessively worn
- 2010 76.6% ball joint excessively worn
- 2011 80.8% coil spring fractured or broken
- 2012 80.4% coil spring fractured or broken
- 2013 80.0% coil spring fractured or broken
- 2014 81.3% coil spring fractured or broken
- 2015 84.7% windscreen damaged but not…
- 2016 84.6% windscreen damaged but not…
- 2017 85.5% windscreen damaged but not…
- 2018 86.3% has a cut in excess of the…
- 2019 85.9% fractured
- 2020 82.9% fractured
- 2021 82.0%fractured
Colour is the pass rate on a fixed scale, so a block means the same thing on any model. Each year links to its own page with the full fault breakdown.
Compare the 2021 Mercedes-Benz Cls with another year
The raw pass rate mostly measures age. The year comparison adds the like-for-like figure, the mileage bands and the repair bill.
Other 2021 cars with a similar record
- Vauxhall Combo 84.0%
- Ford Galaxy 84.1%
- Citroen C4 Sense + 84.8%
- Tesla Model 3 Performance 85.3%
- Toyota Hilux 85.6%
- Citroen E-C4 85.8%
Closest pass rates among 2021 cars with at least 2,000 tests, so a small sample cannot flatter itself into the list. See the full rankings: best and worst MOT pass rates.
The full DVSA record for the 2021 Mercedes-Benz Cls 10 failure items · 6 advisories · 7 inspection categories · mileage brackets · all of it in the page, none of it above the fold
Every inspection category
Shares of the 77 individual items recorded on this vehicle, and the same share across all cars nationally. A single test can record several items, so a row is not a percentage of tests.
| Category | Items | This car | Nationally | Difference |
|---|---|---|---|---|
| Tyres | 36 | 46.80% | 19.76% | +27.04 |
| Road Wheels | 19 | 24.70% | 0.75% | +23.95 |
| Visibility | 8 | 10.40% | 4.97% | +5.43 |
| Brakes | 7 | 9.10% | 20.89% | −11.79 |
| Suspension | 3 | 3.90% | 20.98% | −17.08 |
| Non-component advisories | 3 | 3.90% | 4.18% | −0.28 |
| Lamps, reflectors and electrical equipment | 1 | 1.30% | 12.21% | −10.91 |
The exact failure items, in the tester's words
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Fractured Road Wheels | Major | 9.4% | £20–55 |
| Has ply or cords exposed Tyres | Major | 3.9% | £45–95 |
| Has a bulge, caused by separation or partial failure of its structure Tyres | Major | 3.1% | £45–95 |
| Windscreen damaged but not adversely affecting driver's view Visibility | Minor | 3.1% | £80–200 |
| Ball joint excessively worn Suspension | Major | 1.6% | £18–45 |
| Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres | Major | 1.6% | £45–95 |
| Brake pads less than 1.5 mm thick Brakes | Major | 0.78% | £18–45 |
| Fixing missing Road Wheels | Rectified | 0.78% | £20–55 |
| Has a tear, caused by separation or partial failure of its structure Tyres | Major | 0.78% | £45–95 |
| Not fitted in accordance with side wall instructions Tyres | Major | 0.78% | £45–95 |
Severity is as recorded: Major and Dangerous fail the test outright; Minor and Advisory do not. Costs are estimates from typical UK parts prices — see how they are built.
What testers noted without failing the car
Advisories are the early warnings — the same parts a year or two before they fail. Reading them is how you tell a car that has been maintained from one that has been patched.
| Recorded item | Severity | Tests | Est. cost |
|---|---|---|---|
| Tread depth below requirements of 1.6mm Tyres | Advisory | 9.4% | £45–95 |
| Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres | Advisory | 5.5% | £45–95 |
| Badly distorted Road Wheels | Advisory | 4.7% | £20–55 |
| Brake pads less than 1.5 mm thick Brakes | Advisory | 3.1% | £18–45 |
| Has a tear, caused by separation or partial failure of its structure Tyres | Advisory | 2.3% | £45–95 |
| Brake discs in such a condition that it is seriously weakened Brakes | Advisory | 1.6% | £45–110 |
Pass rate by mileage
| Mileage | Tests | Pass rate | Median odometer |
|---|---|---|---|
| 0-30k | 77 | 85.7% | 20,679 mi |
| 30-60k | 47 | 76.6% | 38,050 mi |
| 60-90k | 4 | 75.0% | 66,812 mi |
Source: 128 recorded tests on this vehicle-year. Every row above is recomputed from the same DVSA extract as the rest of the page — see the methodology.
2021 Cls MOT questions
What is the MOT pass rate for a 2021 Mercedes-Benz Cls?
82.0% of the 128 2021 Mercedes-Benz Cls tests in this dataset passed, against a national average of 91.2% for cars first used in 2021. First-attempt pass rate: 78.5%.
What are the most common MOT failures on a 2021 Mercedes-Benz Cls?
The three most recorded items are fractured (9.38%), has ply or cords exposed (3.91%), has a bulge, caused by separation or partial failure of its structure (3.13%). Percentages are the share of tests on this vehicle that recorded the item.
Does mileage affect the 2021 Mercedes-Benz Cls MOT pass rate?
Yes. Cars under 30,000 miles passed 85.7% of the time, falling to 75.0% for those over 120,000 miles. The median 2021 Mercedes-Benz Cls in this dataset had covered 27,004 mi.
Which fuel type is most reliable for a 2021 Mercedes-Benz Cls?
Diesel: 80.0% pass rate across 100 tests. Hybrid: 89.3% pass rate across 28 tests. Shares are of the tests on this vehicle that recorded each fuel type.
Does the season affect the 2021 Mercedes-Benz Cls MOT pass rate?
Tests recorded in the winter months (October–March) passed 82.7% of the time; summer months (April–September) passed 81.1%. Brakes, tyres and lights are tested harder in bad weather, but the difference is small on most models.