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

In 2025, 78.8% of Mercedes-Benz SLs first used in 1998 passed their MOT first time, against 65.6% for all cars first used in 1998. Across 2,074 SL first tests from 2023 to 2025, the most common failure areas were lamps and electrical equipment, suspension and noise, emissions and leaks.

This page analyses first MOT tests for Mercedes-Benz SLs 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
78.8%
of 680 first tests; all cars first used in 1998: 65.6%. Fixed-at-the-test counts as a fail
Tests analysed
2,074
first tests, 2023–2025; 680 in 2025
Clean pass, 2025
44.6%
of 680 first tests in 2025, passed with no advisory and no minor defect recorded
Typical mileage, tested in 2025
85,500
middle half: 62,000–111,500 miles; all cars first used in 1998: 98,000

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

Share of first tests passed in each year, SLs 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 SL figure was 13.2 points higher.

1998 SLAll cars first used in 1998
60%70%80%90%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 SL, test year 2021: 77.8%1998 SL, test year 2022: 80.6%1998 SL, test year 2023: 81.8%1998 SL, test year 2024: 79.7%1998 SL, test year 2025: 78.8%78.8%65.6%
View this chart as a table
Test year1998 SLAll cars first used 1998SL first tests
202177.8%60.7%748
202280.6%62.4%772
202381.8%64.0%715
202479.7%64.9%679
202578.8%65.6%680

Common 1998 Mercedes-Benz SL MOT failures

Share of the 412 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 equipment43.7%
Suspension28.6%
Noise, emissions and leaks18.4%
Brakes18.2%
Visibility17.0%
Tyres10.0%
Steering9.2%

Most common failure items

DVSA failure itemShare of failed first testsTests
Ball joint dust cover: no longer prevents the ingress of dirt20.1%83

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

What to check on a 1998 Mercedes-Benz SL 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. Suspension. Worth looking behind the front wheels with a torch at the coil springs, and listening for knocks over bumps on the test drive.
  3. Engine and emissions. Worth checking that the engine warning light goes out after starting, looking for oil leaks under the car, and noticing any smoke from the exhaust.

Common 1998 Mercedes-Benz SL MOT advisories

Advisories are points the tester noted that did not fail the car. Most common on 1998 SLs, as a share of all 2,074 first tests, 2023–2025.

DVSA advisory itemShare of first testsTests
Rigid brake pipes: corroded, covered in grease or other material13.1%271
Engine oil leaks: leak, but not excessive10.7%222
Tyre condition: slightly damaged/cracking or perishing7.9%164
Brake discs: worn, pitted or scored, but not seriously weakened6.3%131
Tread depth: worn close to legal limit/worn on edge6.0%125

Questions about the 1998 Mercedes-Benz SL MOT

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

In 2025, 78.8% of SLs 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 SL most often fail its MOT on?

Lamps and electrical equipment (in 43.7% of failed first tests, 2023–2025), suspension (28.6%) and noise, emissions and leaks (18.4%). The single most common item was “Ball joint dust cover: no longer prevents the ingress of dirt” (20.1%).

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

In 2025, 21.2% of first tests on SLs first used in 1998 did not pass first time: 16.2% failed, and a further 5.0% had a fault fixed during the test (counted as a fail here). Across 2023–2025, 412 of 2,074 first tests did not pass first time.

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

“Rigid brake pipes: corroded, covered in grease or other material” (on 13.1% of first tests, 2023–2025), “Engine oil leaks: leak, but not excessive” (10.7%), “Tyre condition: slightly damaged/cracking or perishing” (7.9%), “Brake discs: worn, pitted or scored, but not seriously weakened” (6.3%) and “Tread depth: worn close to legal limit/worn on edge” (6.0%).

Is a 1998 Mercedes-Benz SL 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 77.8% in 2021 to 78.8% 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 SL 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 SL” means a Mercedes-Benz SL 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. 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.