Mercedes-Benz SLK MOT pass rates & common failures

Every completed first-attempt MOT on a Mercedes-Benz SLK in Great Britain in 2025 — 54,181 tests. Figures cover every SLK first-tested in 2025, all trims grouped. How the SLK ages, what it fails on, and what mileage is normal, computed directly from the official DVSA record of every test.

Pass rate 2025
71.9%
0.4 points below the class-4 average (72.3%); unadjusted for age — the age-matched comparison is below
Tests analysed
54,181
first tests, 2025
Arrived with a dangerous fault
6.9%
of SLK first tests; national 7.3%
Typical mileage at 10 years
48,750
middle half: 36,250–66,250 miles (2,500-mile-band midpoints)

How many Mercedes-Benz SLK cars are still on the road?

At the end of 2025, DVLA's register held 60,176 Mercedes-Benz SLK cars that were taxed or on SORN: 47,131 taxed and 13,045 on SORN (Statutory Off Road Notification — kept, but declared off the road by the keeper). The MOT figures above count tests; these count cars, across the whole United Kingdom, cars only. Mercedes-Benz SLK vans, where they exist, are counted by DVLA as goods vehicles and are not in these figures.

Still taxed, end of 2025
47,131
78.3% of the 60,176 SLK cars taxed or on SORN; 56 model variants grouped
On SORN, end of 2025
13,045
declared off the road by their keepers — 21.7% of that total

How the numbers are moving

The number of taxed SLK cars peaked at 67,480 at the end of 2016 and has since fallen by 20,349 (30.2%) to 47,131 at the end of 2025. Cars on SORN went from 3,659 at the end of 2014 to 13,045 at the end of 2025, up 256.5%. A car leaves the taxed count when it is scrapped, exported or declared off the road; the year-end counts do not say which.

Taxed SLK cars, year by year

Cars of this model taxed and on the road at the end of each year, 2014–2025.

020k40k60k80k2014201620182020202220242025Year (count at the end of the year)Taxed SLK cars, year 2014: 63kTaxed SLK cars, year 2015: 67kTaxed SLK cars, year 2016: 67kTaxed SLK cars, year 2017: 65kTaxed SLK cars, year 2018: 63kTaxed SLK cars, year 2019: 60kTaxed SLK cars, year 2020: 58kTaxed SLK cars, year 2021: 57kTaxed SLK cars, year 2022: 55kTaxed SLK cars, year 2023: 52kTaxed SLK cars, year 2024: 49kTaxed SLK cars, year 2025: 47k47k
View this chart as a table
YearTaxed SLK cars
201463,317
201567,138
201667,480
201764,897
201862,861
201960,423
202058,380
202156,729
202254,770
202351,918
202449,159
202547,131

SLK cars on SORN, year by year

Cars of this model declared off the road at the end of each year, 2014–2025. Its own scale — SORN counts are a fraction of the taxed count.

05k10k15k2014201620182020202220242025Year (count at the end of the year)SLK cars on SORN, year 2014: 4kSLK cars on SORN, year 2015: 4kSLK cars on SORN, year 2016: 5kSLK cars on SORN, year 2017: 6kSLK cars on SORN, year 2018: 7kSLK cars on SORN, year 2019: 8kSLK cars on SORN, year 2020: 10kSLK cars on SORN, year 2021: 10kSLK cars on SORN, year 2022: 11kSLK cars on SORN, year 2023: 12kSLK cars on SORN, year 2024: 12kSLK cars on SORN, year 2025: 13k13k
View this chart as a table
YearSLK cars on SORN
20143,659
20154,231
20165,106
20176,219
20187,234
20198,303
20209,929
20219,946
202210,595
202311,547
202412,380
202513,045

Which model years survive

Taxed SLK cars at the end of 2025 by year of manufacture, and each year's share of the 47,131 taxed in all. Every build year holding at least 1% has its own row; the rest share one. 3 taxed SLK cars have no recorded year of manufacture and are not in the table, so the rows add up to 47,128. A build year's count depends on how many were sold that year as well as how many have lasted.

Year of manufacture Taxed, end of 2025Share of taxed SLK cars
20161,2142.6%
20154,6169.8%
20144,5929.7%
20134,2869.1%
20125,14210.9%
20112,3475.0%
20101,8423.9%
20092,1774.6%
20082,7595.9%
20072,7935.9%
20062,8456.0%
20053,5917.6%
20042,1994.7%
20031,1952.5%
20021,2512.7%
20011,3562.9%
20001,0692.3%
19998071.7%
19986241.3%
All other build years (five years, each under 1%)4230.9%

Population source: Department for Transport / DVLA vehicle licensing statistics, table VEH0124, updated 15 July 2026; counts of the cars on DVLA's register that were taxed or on SORN at the end of each year shown, United Kingdom, cars only, excluding cars recorded with no model name. SortedCars groups DVLA's model name SLK CLASS under this model. Contains public sector information licensed under the Open Government Licence v3.0. SortedCars is not affiliated with, or endorsed by, DVLA or the Department for Transport.

How the SLK ages

First-time pass rate by vehicle age, SLK vs all cars, 2025.

Mercedes-Benz SLKAll cars
50%60%70%80%90%100%3579111315171920Vehicle age (years)Mercedes-Benz SLK, vehicle age 9: 82.3%Mercedes-Benz SLK, vehicle age 10: 80%Mercedes-Benz SLK, vehicle age 11: 76.4%Mercedes-Benz SLK, vehicle age 12: 74.3%Mercedes-Benz SLK, vehicle age 13: 73.7%Mercedes-Benz SLK, vehicle age 14: 75.2%Mercedes-Benz SLK, vehicle age 15: 70.6%Mercedes-Benz SLK, vehicle age 16: 69.3%Mercedes-Benz SLK, vehicle age 17: 67.9%Mercedes-Benz SLK, vehicle age 18: 67.3%Mercedes-Benz SLK, vehicle age 19: 67%Mercedes-Benz SLK, vehicle age 20: 67.9%All cars, vehicle age 3: 88.5%All cars, vehicle age 4: 87.2%All cars, vehicle age 5: 86%All cars, vehicle age 6: 83.5%All cars, vehicle age 7: 80.9%All cars, vehicle age 8: 78.2%All cars, vehicle age 9: 74.9%All cars, vehicle age 10: 71.9%All cars, vehicle age 11: 68.6%All cars, vehicle age 12: 65.8%All cars, vehicle age 13: 63.5%All cars, vehicle age 14: 61.2%All cars, vehicle age 15: 59.3%All cars, vehicle age 16: 58.3%All cars, vehicle age 17: 57.2%All cars, vehicle age 18: 57.4%All cars, vehicle age 19: 57%All cars, vehicle age 20: 57.6%Mercedes-Benz SLK 67.9%All cars 57.6%
View this chart as a table
Age (years)SLK testsSLK pass rateAll cars
91,24982.3%74.9%
104,84880.0%71.9%
114,79176.4%68.6%
124,48874.3%65.8%
135,48173.7%63.5%
142,48775.2%61.2%
152,03170.6%59.3%
162,44969.3%58.3%
173,11567.9%57.2%
183,38967.3%57.4%
193,47367.0%57.0%
204,42267.9%57.6%

Better or worse than the average car?

The SLK's pass rate minus the all-cars pass rate at each age, in percentage points. Bars above zero: the SLK beats the average car of that age. Below zero: it trails.

SLK ahead
-16-8+0+8+16Age 9: +7.4 points vs the average car9Age 10: +8.1 points vs the average carAge 11: +7.8 points vs the average car11Age 12: +8.5 points vs the average carAge 13: +10.2 points vs the average car13Age 14: +14.0 points vs the average carAge 15: +11.3 points vs the average car15Age 16: +11.0 points vs the average carAge 17: +10.7 points vs the average car17Age 18: +9.9 points vs the average carAge 19: +10.0 points vs the average car19Age 20: +10.3 points vs the average car20Vehicle age (years)
View this chart as a table
Age (years)Gap (points)
9+7.4
10+8.1
11+7.8
12+8.5
13+10.2
14+14.0
15+11.3
16+11.0
17+10.7
18+9.9
19+10.0
20+10.3

The SLK fleet on the road, by age

How many took a first MOT in 2025 at each age — the shape of the SLK fleet still in use.

01k3k4k6kAge 9: 1k9Age 10: 4kAge 11: 4k11Age 12: 4kAge 13: 5k13Age 14: 2kAge 15: 2k15Age 16: 2kAge 17: 3k17Age 18: 3kAge 19: 3k19Age 20: 4k20Vehicle age (years)
View this chart as a table
Age (years)First tests
91,249
104,848
114,791
124,488
135,481
142,487
152,031
162,449
173,115
183,389
193,473
204,422

What an SLK fails on

Where the failure items land when an SLK fails or needs a fix at test, 2025. Use it as a pre-purchase checklist: these are the areas to look at first.

Suspension28.8%
Lamps, reflectors and electrical equipment20.6%
Brakes16.3%
Tyres14.1%
Visibility6.4%
Noise, emissions and leaks5.4%
Body, chassis, structure2.7%
Seat belts and supplementary restraint systems2.3%

Share of all failure items, 2025 — the 8 biggest categories shown (96.6% of the items); smaller categories are not listed.

The advisories to watch

Where testers most often write "keep an eye on this" for a SLK, 2025 — the faults in the post.

Brakes: 31.0% of advisories31.0%Tyres: 26.9% of advisories26.9%Suspension: 24.1% of advisories24.1%Noise, emissions and leaks: 3.9% of advisoriesBody, chassis, structure: 3.7% of advisoriesLamps, reflectors and electrical equipment: 3.5% of advisories
BrakesTyresSuspensionNoise, emissions and leaksBody, chassis, structureLamps, reflectors and electrical equipment
View this chart as a table
CategoryShare of advisories
Brakes31.0%
Tyres26.9%
Suspension24.1%
Noise, emissions and leaks3.9%
Body, chassis, structure3.7%
Lamps, reflectors and electrical equipment3.5%

Petrol, diesel or hybrid SLK?

First-time pass rate for the two most-tested SLK fuel types, 2025, against the all-cars average. Fleet ages differ by fuel — newer fleets help the electrified bars.

50%60%70%80%90%100%all cars 72.3%Petrol: 71.1% of 40,998 tests71.1%Petrol40,998 testsDiesel: 74.2% of 13,177 tests74.2%Diesel13,177 tests
View this chart as a table
FuelTestsPass rate
Petrol40,99871.1%
Diesel13,17774.2%

What mileage is normal for an SLK?

Mileage recorded at test by vehicle age, 2025. The line is the typical (median) SLK; the shaded band holds the middle half. A car far outside the band, in either direction, is worth questions the recorded history can answer.

Typical SLK (median)
0k25k50k75k100k125k9111315171920Vehicle age (years)Age 9: typical 43,750 miles (middle half 31,250–58,750)Age 10: typical 48,750 miles (middle half 36,250–66,250)Age 11: typical 56,250 miles (middle half 41,250–73,750)Age 12: typical 63,750 miles (middle half 48,750–81,250)Age 13: typical 63,750 miles (middle half 48,750–83,750)Age 14: typical 61,250 miles (middle half 46,250–78,750)Age 15: typical 66,250 miles (middle half 48,750–83,750)Age 16: typical 68,750 miles (middle half 51,250–88,750)Age 17: typical 73,750 miles (middle half 56,250–93,750)Age 18: typical 76,250 miles (middle half 56,250–96,250)Age 19: typical 78,750 miles (middle half 58,750–101,250)Age 20: typical 81,250 miles (middle half 61,250–101,250)81k mi

Mileage values are midpoints of 2,500-mile bands.

View this chart as a table
Age (years)Lower quarterTypical (median)Upper quarter
931,25043,75058,750
1036,25048,75066,250
1141,25056,25073,750
1248,75063,75081,250
1348,75063,75083,750
1446,25061,25078,750
1548,75066,25083,750
1651,25068,75088,750
1756,25073,75093,750
1856,25076,25096,250
1958,75078,750101,250
2061,25081,250101,250

What fails at each age

The SLK's failure mix by age band, 2025 — each band's top categories at their true share of that band's failure items; the pale remainder is everything else. How the mix shifts with age is the point of the chart.

TyresSuspensionBrakesLamps, reflectors and electrical equipmentNoise, emissions and leaksVisibilityEverything else
View this chart as a table
Age bandCategoryShare of the band's failure items
6-9 yrsTyres34.8%
6-9 yrsSuspension30.1%
6-9 yrsBrakes12.4%
6-9 yrsLamps, reflectors and electrical equipment6.8%
6-9 yrsNoise, emissions and leaks6.5%
6-9 yrsEverything else9.4%
10-13 yrsSuspension40.8%
10-13 yrsTyres26.8%
10-13 yrsBrakes14.3%
10-13 yrsLamps, reflectors and electrical equipment7.2%
10-13 yrsVisibility3.7%
10-13 yrsEverything else7.2%
14+ yrsSuspension27.9%
14+ yrsLamps, reflectors and electrical equipment20.2%
14+ yrsBrakes18.7%
14+ yrsTyres10.7%
14+ yrsNoise, emissions and leaks6.3%
14+ yrsEverything else16.2%

More vehicles we've checked

How these figures are computed. Every number on this page is calculated by SortedCars from the DVSA anonymised MOT results dataset (every MOT test in Great Britain — 2025 for single-year figures; trend figures state their span, currently 2023–2025). Where a figure comes from a sample or uses banded values (mileage is banded to 2,500 miles), the page says so beside the figure. Test class 4 only, first tests only — retests are excluded. Class 4 is the car MOT class and also covers car-derived vans, pickups and motorhomes tested to the same standard; where this page says "cars" it means class 4. Pass rate = passes ÷ (passes + failures + pass-after-rectification): a vehicle that failed and was fixed during the visit counts as a fail. Pass rates describe fleets, not individual machines: they reflect how cars were driven, maintained and used as well as how they were built, and beyond recorded mileage none of that is in the data. A well-kept example of a model with a weak average can still pass; a neglected example of a strong one can still fail. No figure is shown for any group with fewer than 500 tests. Alias spellings of a make in the DVSA file are counted under one make name, and all trims and variants of a model are grouped under one model name, using SortedCars' grouping tables. The taxed and SORN counts on this page are the one exception: they are not computed from MOT records but taken from the Department for Transport's vehicle licensing statistics (DfT/DVLA table VEH0124, updated 15 July 2026, Open Government Licence v3.0), which count the cars on DVLA's register that were taxed or on SORN at the end of each year shown, UK-wide, cars only. They describe a model as a whole, grouped under SortedCars' model names, and say nothing about any one car. “Dangerous” is DVSA's statutory defect category (in force since May 2018): a defect posing an immediate risk to road safety — driving the vehicle before repair is an offence. What these figures are for. These statistics are general information about groups of vehicles. They are not advice, a valuation or a recommendation to buy, avoid or price any particular vehicle, and no decision about one car should rest on them alone — check the car itself and its own records. We take care over the calculations, but we cannot guarantee they are complete, current or free of error, and we accept no liability for loss arising from reliance on them. This does not limit any liability that cannot lawfully be limited — see our Terms & Conditions. If you believe any figure on this page is inaccurate, contact us. SortedCars is not affiliated with, or endorsed by, the DVSA or DVLA. DVSA publishes the raw test records; the statistics on this page are SortedCars' own calculations from them. Contains public sector information licensed under the Open Government Licence v3.0.