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Mercedes-Benz SLK R172 (3rd gen) (2011-2020) reliability

Not enough data

Mercedes-Benz SLK R172 (3rd gen) built around 2017: not enough MOT data yet

We've only seen a handful of Mercedes-Benz SLK R172 (3rd gen) models built around 2017 so far. Too few to spot a pattern yet.

Looking at a Mercedes-Benz SLK R172 (3rd gen) right now?

Enter its number plate to see its full MOT history, risk rating and running costs.

Key figure

Check a car’s number plate to see its own MOT record, or come back when there’s more MOT history.

Mercedes-Benz SLK R172 (3rd gen)
2011-2020ConvertibleDIESEL / PETROL

Based on 28,785 tests of SLK models registered 2011-2020.

R172 (3rd gen) fail rate by age

Below typicalAbove typicalHigh (28% or more)Highest fail rateUK average for cars this age
Age / builtFail rateMOT tests
8 yearsbuilt around 2017
26010.8%
9 yearsbuilt around 2016
3,43916.5%
10 yearsbuilt around 2015
5,86117.6%
11 yearsbuilt around 2014
5,87820.2%
12 yearsbuilt around 2013
6,76520.9%
13 yearsbuilt around 2012
5,30320.5%
14 yearsbuilt around 2011
1,27920.1%

Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs. Highest fail rate at 12 years old.

How the SLK R172 (3rd gen) compares

At each age below, see how the SLK R172 (3rd gen) holds up against other cars the same age. The averages combine all fuel types.

Based on 184,960 tests across 17 Mercedes-Benz models, built around 2017 (8 years old).

Below typicalAbove typicalHigh (28% or more)Highest fail rateMercedes-Benz average
Age / builtFail rateMOT tests
8 yearsbuilt around 2017
26010.8%
9 yearsbuilt around 2016
3,43916.5%
10 yearsbuilt around 2015
5,86117.6%
11 yearsbuilt around 2014
5,87820.2%
12 yearsbuilt around 2013
6,76520.9%
13 yearsbuilt around 2012
5,30320.5%
14 yearsbuilt around 2011
1,27920.1%

Fail rate is the share of MOT tests that ended in a fail. Retests count as tests. How we count fail rates Build years are worked out from age, so they are approximate. Tests counted are 2025 MOTs.

What to check before viewing

The model's most common MOT issues, turned into things you can ask about or look for.

Brake discs

High priority

Ask for the date and mileage of the last disc replacement; visually check for a deep wear lip and rust pitting on each disc.

Brake pads

High priority

Ask when the pads were last replaced and check the warning-light history.

Tyres

Worth checking

Check tread depth across the full width on all four; uneven wear suggests alignment or suspension issues.

Axles & Wheels

Worth checking

Inspect the axles & wheels carefully and ask the seller for repair history.

Vehicle-specific check

Worth checking

Check the car’s number plate on MOT Wise to see its own MOT history and any recalls for its build years.

Other convertibles to compare

Other convertibles, with each one's figures taken at the same age as the SLK R172 (3rd gen).

  1. 1

    Porsche Boxster

    Same body type, tested at the same age

    Fail rate
    5.7%
    Fail, no pass in 3 days
    1.5%
    Dangerous
    2.7%
    Still registered at 10 years
    97.9%

    Lower fail rate: 5.7%, against 10.8% for the Mercedes-Benz SLK R172 (3rd gen), both built around 2017.

    1,141 MOT tests on cars built around 2017

  2. 2

    Mazda MX-5

    Same body type, tested at the same age

    Fail rate
    10.3%
    Fail, no pass in 3 days
    1.8%
    Dangerous
    3.1%
    Still registered at 10 years
    97.6%

    No clear edge over the Mercedes-Benz SLK R172 (3rd gen) on these figures.

    4,704 MOT tests on cars built around 2017

Fail rate
= the share of MOT tests that ended in a fail. Retests count as tests.
Fail, no pass in 3 days
= the share of MOT tests that failed and still hadn't passed 3 days later. A fail that passed a retest within 3 days, even the same day, isn't counted.
Dangerous
= the share of MOT tests where the tester marked a fault as dangerous. It is against the law to drive the car until it is fixed.
Still registered at 10 years
= the share of cars still registered (taxed or declared off the road) 10 years after they were first registered.

How many are still registered

93%of all Mercedes-Benz SLK cars first registered in 2014 to 2015 were still registered 10 years later. This is the whole model, not only this generation.

UK average for cars first registered in 2014 to 2015: 92% · About typical

The share still registered can reflect demand, the cost of repairs, exports, write-offs and how owners use the car. It isn't proof of how long the car lasts mechanically.

Source: DfT vehicle licensing statistics (VEH0124).

Recall context

26 recalls in all

14 of the 26 SLK R172 (3rd gen) recalls cover cars built in these years.

  • 2 Critical
  • 12 more

Top concerns

  • Brakes may overheat creating a risk of smoke and/or fire
  • Risk of fire
  • The behaviour of the emergency call system might not meet specifications

For the exact car, check GOV.UK's recall checker with the number plate.

How SLK R172 (3rd gen) cars have aged

How SLK R172 (3rd gen) cars have aged

How fail rates have changed as these cars got older. Each line follows cars first registered in about the same year across several years of MOT data. Not a prediction for any one car.

0%10%20%5791113Age at MOTBuilt around 2016, 5 years old at the time of MOT: 10.3% (1,169 tests, 2021 data)Built around 2016, 6 years old at the time of MOT: 10.4% (1,138 tests, 2022 data)Built around 2016, 7 years old at the time of MOT: 12.3% (1,186 tests, 2023 data)Built around 2016, 8 years old at the time of MOT: 15.1% (1,177 tests, 2024 data)Built around 2016, 9 years old at the time of MOT: 16.1% (1,212 tests, 2025 data)2016Built around 2015, 6 years old at the time of MOT: 12.3% (3,785 tests, 2021 data)Built around 2015, 7 years old at the time of MOT: 12.9% (3,672 tests, 2022 data)Built around 2015, 8 years old at the time of MOT: 15.9% (3,663 tests, 2023 data)Built around 2015, 9 years old at the time of MOT: 16.8% (3,588 tests, 2024 data)Built around 2015, 10 years old at the time of MOT: 16.8% (3,583 tests, 2025 data)2015Built around 2014, 7 years old at the time of MOT: 13.8% (3,857 tests, 2021 data)Built around 2014, 8 years old at the time of MOT: 14.7% (3,722 tests, 2022 data)Built around 2014, 9 years old at the time of MOT: 16.8% (3,731 tests, 2023 data)Built around 2014, 10 years old at the time of MOT: 18.3% (3,653 tests, 2024 data)Built around 2014, 11 years old at the time of MOT: 19.5% (3,638 tests, 2025 data)2014Built around 2013, 8 years old at the time of MOT: 16.5% (3,630 tests, 2021 data)Built around 2013, 9 years old at the time of MOT: 18.2% (3,547 tests, 2022 data)Built around 2013, 10 years old at the time of MOT: 19.4% (3,541 tests, 2023 data)Built around 2013, 11 years old at the time of MOT: 20.0% (3,461 tests, 2024 data)Built around 2013, 12 years old at the time of MOT: 20.0% (3,395 tests, 2025 data)2013Built around 2012, 9 years old at the time of MOT: 17.9% (3,932 tests, 2021 data)Built around 2012, 10 years old at the time of MOT: 18.9% (3,862 tests, 2022 data)Built around 2012, 11 years old at the time of MOT: 19.7% (3,741 tests, 2023 data)Built around 2012, 12 years old at the time of MOT: 21.2% (3,624 tests, 2024 data)Built around 2012, 13 years old at the time of MOT: 20.6% (3,509 tests, 2025 data)2012Built around 2011, 10 years old at the time of MOT: 17.8% (1,501 tests, 2021 data)Built around 2011, 11 years old at the time of MOT: 18.4% (1,404 tests, 2022 data)Built around 2011, 12 years old at the time of MOT: 18.9% (1,357 tests, 2023 data)Built around 2011, 13 years old at the time of MOT: 19.0% (1,313 tests, 2024 data)Built around 2011, 14 years old at the time of MOT: 20.1% (1,279 tests, 2025 data)2011
First registered around 2016First registered around 2015First registered around 2014First registered around 2013
All generations of this modelNot enough data

Most common issues on Mercedes-Benz SLK models of this age

This list covers every Mercedes-Benz SLK built around 2017, whichever generation it is. We don't have a defect list for the R172 (3rd gen) on its own.

Most common advisories and fails

In order of the share of MOT tests that recorded each one

  1. 1
    Advisory

    Tyre worn close to the legal limit or worn on the edge

    17.7%
    Advisory: 72Fail: 5 (6% of the times it was found)
  2. 2
    Advisory

    Brake disc worn, pitted or scored, but not seriously weakened

    7.7%
    Advisory: 40Fail: 0 (0% of the times it was found)
  3. 3
    Advisory

    Tyre slightly damaged, cracking or perishing

    6.9%
    Advisory: 20Fail: 7 (26% of the times it was found)
  4. 4
    Advisory

    Wheel bearing has slight play

    6.9%
    Advisory: 25Fail: 1 (4% of the times it was found)
  5. 5
    Advisory

    Brake pads wearing thin

    5.8%
    Advisory: 22Fail: 0 (0% of the times it was found)

Based on 260 tests

Looking at a Mercedes-Benz SLK R172 (3rd gen) right now?

Enter its number plate to see its full MOT history, risk rating and running costs.

Frequently asked questions

Built around 2017 (8 years old), the Mercedes-Benz SLK R172 (3rd gen) (2011-2020) fails MOTs noticeably less often than typical for this age. This is based on 260 8-year-old MOT tests from DVSA data. Each retest counts as a test.

*The build year is worked out from the date a car was first used on UK roads. For most cars this matches when it was registered, but imports may differ by a few months.

Data sourced from DVSA MOT History API. From 28,785 MOT tests on Mercedes-Benz SLK models first registered between 2011-2020. These figures are a guide, not a guarantee.