2018 Mercedes-Benz SLC MOT pass rate, common failures & what to check

In 2025, 88.8% of Mercedes-Benz SLCs first used in 2018 passed their MOT first time, against 80.9% for all cars first used in 2018. Across 4,505 SLC first tests from 2023 to 2025, the most common failure areas were tyres, lamps and electrical equipment and suspension.

This page analyses first MOT tests for Mercedes-Benz SLCs first used in 2018 (all trims grouped): 2021 to 2025 for the pass-rate trend, and 2023 to 2025 for the failure and advisory analysis — plus what is worth checking before you buy one.

Data: DVSA anonymised MOT tests to December 2025 · Calculated by SortedCars · Updated October 2026

Passed first time, 2025
88.8%
of 1,495 first tests; all cars first used in 2018: 80.9%. Fixed-at-the-test counts as a fail
Tests analysed
4,505
first tests, 2023–2025; 1,495 in 2025
Clean pass, 2025
62.8%
of 1,495 first tests in 2025, passed with no advisory and no minor defect recorded
Typical mileage, tested in 2025
30,000
middle half: 20,000–41,000 miles; all cars first used in 2018: 52,000

How the 2018 Mercedes-Benz SLC MOT pass rate has changed

Share of first tests passed in each year, SLCs first used in 2018 against all cars first used in 2018 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the SLC figure was 7.9 points higher.

2018 SLCAll cars first used in 2018
80%90%100%20212022202320242025Test year (first tests)All cars first used in 2018, test year 2021: 87.6%All cars first used in 2018, test year 2022: 86.3%All cars first used in 2018, test year 2023: 84.2%All cars first used in 2018, test year 2024: 82.5%All cars first used in 2018, test year 2025: 80.9%2018 SLC, test year 2021: 91.2%2018 SLC, test year 2022: 90.7%2018 SLC, test year 2023: 90%2018 SLC, test year 2024: 88.1%2018 SLC, test year 2025: 88.8%88.8%80.9%
View this chart as a table
Test year2018 SLCAll cars first used 2018SLC first tests
202191.2%87.6%1,571
202290.7%86.3%1,548
202390.0%84.2%1,509
202488.1%82.5%1,501
202588.8%80.9%1,495

Common 2018 Mercedes-Benz SLC MOT failures

Share of the 497 failed first tests (2023–2025) with at least one failure in each area. A test can fail in more than one area, so the shares add up to more than 100%.

Tyres54.3%
Lamps, reflectors and electrical equipment15.3%
Suspension13.3%
Brakes9.5%
Noise, emissions and leaks7.6%
Visibility6.4%

Most common failure items

DVSA failure itemShare of failed first testsTests
Tyre condition: has ply or cords exposed19.9%99
Tyre condition: has a cut in excess of the requirements deep enough to reach the ply or cords18.9%94

Item names are DVSA’s own wording. 2023–2025 combined.

What to check on a 2018 Mercedes-Benz SLC before buying

The three areas where failed first tests most often had a fault, 2023–2025.

  1. Tyres. Worth checking the tread depth across the whole width of each tyre, and the sidewalls for cuts, cracks and bulges.
  2. Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
  3. Suspension. Worth looking behind the front wheels with a torch at the coil springs, and listening for knocks over bumps on the test drive.

Common 2018 Mercedes-Benz SLC MOT advisories

Advisories are points the tester noted that did not fail the car. Most common on 2018 SLCs, as a share of all 4,505 first tests, 2023–2025.

DVSA advisory itemShare of first testsTests
Tread depth: worn close to legal limit/worn on edge12.9%579
Tyre condition: slightly damaged/cracking or perishing8.8%398
Tyre condition: has a cut but not deep enough to reach the ply or cords4.0%181
Brake discs: worn, pitted or scored, but not seriously weakened2.0%88
Tyre condition: slightly damaged1.9%87

Questions about the 2018 Mercedes-Benz SLC MOT

What is the MOT pass rate of a 2018 Mercedes-Benz SLC?

In 2025, 88.8% of SLCs first used in 2018 passed their MOT first time, against 80.9% for all cars first used in 2018. A car fixed during the test counts as a fail.

What does a 2018 SLC most often fail its MOT on?

Tyres (in 54.3% of failed first tests, 2023–2025), lamps and electrical equipment (15.3%) and suspension (13.3%). The single most common item was “Tyre condition: has ply or cords exposed” (19.9%).

How often does a 2018 Mercedes-Benz SLC fail its MOT?

In 2025, 11.2% of first tests on SLCs first used in 2018 did not pass first time: 10.0% failed, and a further 1.2% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 497 of 4,505 first tests did not pass first time.

What are the most common 2018 Mercedes-Benz SLC MOT advisories?

“Tread depth: worn close to legal limit/worn on edge” (on 12.9% of first tests, 2023–2025), “Tyre condition: slightly damaged/cracking or perishing” (8.8%), “Tyre condition: has a cut but not deep enough to reach the ply or cords” (4.0%), “Brake discs: worn, pitted or scored, but not seriously weakened” (2.0%) and “Tyre condition: slightly damaged” (1.9%).

Is a 2018 Mercedes-Benz SLC reliable?

An MOT pass rate shows what failed at the test, not how reliable a car is. For this group of cars the first-time pass rate went from 91.2% in 2021 to 88.8% in 2025. For one particular car, its own MOT history matters more than the average.

Other cars first used in 2018

The most-tested cars from the same year. Each page uses the same method.

2018 Ford Fiesta MOT statistics · 2018 Volkswagen Golf MOT statistics · 2018 Vauxhall Corsa MOT statistics · 2018 Ford Focus MOT statistics · 2018 Nissan Qashqai MOT statistics

How the 2018 Mercedes-Benz SLC MOT data is calculated

Every number on this page is calculated by SortedCars from DVSA’s anonymised MOT test data for Great Britain, 2021–2025. “2018 SLC” means a Mercedes-Benz SLC whose date of first use falls in 2018 (67, 18 and 68 plates), all trims grouped. Class 4 vehicles, first tests only — retests are not counted. Pass rate = passed ÷ all first tests; a car with a fault fixed during the test (PRS) counts as a fail. Our national first-test pass rate matches DVSA’s published figure (table DVSA/MOT/01) to within 0.04 points in every year. Clean pass = passed with no advisory and no minor defect recorded. Mileage is the reading recorded at the test. Comparisons are with all cars first used in 2018, any make or fuel, and are not adjusted for mileage, fuel or use. Failure and advisory item names are DVSA’s own wording. No figure is shown for fewer than 500 tests; an item is shown only if it appears on at least 50 tests and 1% of the base. Pass rates describe a group of cars, not one car: a well-kept example can pass and a neglected one can fail. This page is general information, not advice about any particular vehicle; always have a used car inspected before you buy. SortedCars is not affiliated with or endorsed by DVSA. You can check any car’s MOT history free on the official service: gov.uk/check-mot-history. Contains public sector information licensed under the Open Government Licence v3.0.