1998 Mercedes-Benz SLK MOT pass rate, common failures & what to check

In 2025, 70.3% of Mercedes-Benz SLKs first used in 1998 passed their MOT first time, against 65.6% for all cars first used in 1998. Across 3,062 SLK first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, brakes and suspension.

This page analyses first MOT tests for Mercedes-Benz SLKs first used in 1998 (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
70.3%
of 885 first tests; all cars first used in 1998: 65.6%. Fixed-at-the-test counts as a fail
Tests analysed
3,062
first tests, 2023–2025; 885 in 2025
Clean pass, 2025
32.8%
of 885 first tests in 2025, passed with no advisory and no minor defect recorded
Typical mileage, tested in 2025
85,500
middle half: 61,500–107,500 miles; all cars first used in 1998: 98,000

How the 1998 Mercedes-Benz SLK MOT pass rate has changed

Share of first tests passed in each year, SLKs first used in 1998 against all cars first used in 1998 (any make or fuel; not adjusted for mileage, fuel or use). In 2025 the SLK figure was 4.7 points higher.

1998 SLKAll cars first used in 1998
60%70%80%20212022202320242025Test year (first tests)All cars first used in 1998, test year 2021: 60.7%All cars first used in 1998, test year 2022: 62.4%All cars first used in 1998, test year 2023: 64%All cars first used in 1998, test year 2024: 64.9%All cars first used in 1998, test year 2025: 65.6%1998 SLK, test year 2021: 64.8%1998 SLK, test year 2022: 68.4%1998 SLK, test year 2023: 69.3%1998 SLK, test year 2024: 66.1%1998 SLK, test year 2025: 70.3%70.3%65.6%
View this chart as a table
Test year1998 SLKAll cars first used 1998SLK first tests
202164.8%60.7%1,576
202268.4%62.4%1,364
202369.3%64.0%1,164
202466.1%64.9%1,013
202570.3%65.6%885

Common 1998 Mercedes-Benz SLK MOT failures

Share of the 963 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%.

Lamps, reflectors and electrical equipment61.4%
Brakes24.6%
Suspension20.6%
Visibility17.9%
Tyres12.6%
Noise, emissions and leaks11.4%
Body, chassis, structure10.3%
Steering5.8%

Most common failure items

DVSA failure itemShare of failed first testsTests
Stop lamp: not working20.5%197
Headlamp aim: projected beam image is obviously incorrect10.6%102
Position lamp: not working9.4%91
Wipers: does not clear the windscreen effectively7.7%74
Coil spring: fractured or broken7.3%70

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

Typical repair costs for common MOT failures

Typical UK garage prices for the job, not for an SLK in particular, and not a quote.

Failure itemTypical jobTypical UK priceUsual range
Coil spring: fractured or brokenCoil spring replacement£248£175–£400

From published UK repair-cost guides, checked September 2026. Only jobs with a published typical price are shown.

What to check on a 1998 Mercedes-Benz SLK before buying

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

  1. Lamps and electrics. Ask someone to watch while you work the brake lights, indicators, sidelights, dipped and main beam, and the number-plate lamps.
  2. Brakes. Worth looking at the discs and pads through the wheel spokes for scoring and a worn lip, and noticing on the test drive whether the car pulls to one side or the pedal feels long.
  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 1998 Mercedes-Benz SLK MOT advisories

Advisories are points the tester noted that did not fail the car. Most common on 1998 SLKs, as a share of all 3,062 first tests, 2023–2025.

DVSA advisory itemShare of first testsTests
Rigid brake pipes: corroded, covered in grease or other material17.0%520
Tread depth: worn close to legal limit/worn on edge11.9%364
Tyre condition: slightly damaged/cracking or perishing10.8%331
Sub-frame: corroded but not seriously weakened10.2%313
Transmission oil leaks: leak, but not excessive6.6%203

Questions about the 1998 Mercedes-Benz SLK MOT

What is the MOT pass rate of a 1998 Mercedes-Benz SLK?

In 2025, 70.3% of SLKs first used in 1998 passed their MOT first time, against 65.6% for all cars first used in 1998. A car fixed during the test counts as a fail.

What does a 1998 SLK most often fail its MOT on?

Lamps and electrical equipment (in 61.4% of failed first tests, 2023–2025), brakes (24.6%) and suspension (20.6%). The single most common item was “Stop lamp: not working” (20.5%).

How often does a 1998 Mercedes-Benz SLK fail its MOT?

In 2025, 29.7% of first tests on SLKs first used in 1998 did not pass first time: 24.0% failed, and a further 5.8% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 963 of 3,062 first tests did not pass first time.

What are the most common 1998 Mercedes-Benz SLK MOT advisories?

“Rigid brake pipes: corroded, covered in grease or other material” (on 17.0% of first tests, 2023–2025), “Tread depth: worn close to legal limit/worn on edge” (11.9%), “Tyre condition: slightly damaged/cracking or perishing” (10.8%), “Sub-frame: corroded but not seriously weakened” (10.2%) and “Transmission oil leaks: leak, but not excessive” (6.6%).

Is a 1998 Mercedes-Benz SLK 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 64.8% in 2021 to 70.3% in 2025. For one particular car, its own MOT history matters more than the average.

Other cars first used in 1998

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

1998 Volkswagen Transporter MOT statistics · 1998 Land Rover Defender MOT statistics · 1998 Mazda MX-5 MOT statistics · 1998 BMW Z3 MOT statistics · 1998 BMW 3 Series MOT statistics

How the 1998 Mercedes-Benz SLK 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. “1998 SLK” means a Mercedes-Benz SLK whose date of first use falls in 1998 (R and S 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 1998, 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. Repair prices are typical UK prices for the job from published UK repair-cost guides, checked September 2026 — not for this model, and not a quote. 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.