2018 Mercedes-Benz Sl MOT pass rate

Pass rate

92.0%

Above average — 4.1 pts ahead of the 87.9% that cars this age and mileage manage.

Across 1,283 recorded tests.

Typical repair bill £45–£106

Which year to buy

  • Best 2020 93.7% pass
  • Avoid 2010 84.9% pass

Across the 22 years on record, a spread of 8.8 points. See every year →

First-attempt pass
91.4%
Typical mileage
23k mi

The 2018 Mercedes-Benz Sl MOT pass rate is 92.0% of its MOT tests — 4.1 points ahead of what its age and mileage predict. Tyres is the biggest single reason it fails, at 56.3% of what testers record.

MOT PASS RATES

The 2018 Mercedes-Benz Sl on the real record

92.0% of 2018 Mercedes-Benz Sl MOTs passed — 1,283 tests, 2023–2025

Pass rate

The answer from the DVSA's class-4 MOT records.

Check your postcode

MOT pass rates are national — type your postcode to see how Mercedes-Benz Sl does in your corner of the country.

How one model's pass rate varies by postcode →

Expert verdict

Tyres: 2.8× the national share

Tyres make up 56.3% of everything recorded on the 2018 Mercedes-Benz Sl, against 19.8% nationally — 36.5 points above. Check all four tyres yourself, including the inner shoulders, and look at the date stamp — a tyre can pass on tread and still be six years old.

Written from this page's own figures: fault shares against the national composition, the like-for-like pass rate, and the priced repair list. How these are worked out

Watching a Mercedes-Benz Sl? Get an email when these numbers change .

Every Mercedes-Benz Sl first registered in 2018 is combined here — 2 trim and body variants in total — so the sample is as large as the DVSA data allows.

How does the 2018 Mercedes-Benz Sl compare?

Cars of this age and mileage average 87.9%, so this figure is 4.1 points ahead of what its age and mileage predict. On a first attempt, before any retests, the figure drops to 91.4%. The median 2018 Mercedes-Benz Sl in this dataset had covered 22,948 mi.

Pass rates also shift with the test month: tests recorded October–March passed 91.1% of the time, April–September 92.8%.

The single most recorded failure item is "Windscreen damaged but not adversely affecting driver's view", noted on 1.64% of tests.

  • 1,283 recorded tests behind this page.
  • 92.0% overall pass rate, 91.4% on a first attempt.
  • Across every year of the Mercedes-Benz Sl, the average is 87.2% — best year 2020 (93.7%), worst 2010 (84.9%).

Figures count every completed test on this vehicle-year in the dataset, including retests. See methodology for the exact definition.

This page's data

Tests analysed
1,283
Typical mileage (median)
22,948 mi
Make and model
Mercedes-Benz Sl
Updated
2026-11-05

Source: DVSA anonymised MOT test data (2023–2025), OGL v3.0.

Top part to budget for

Windscreen

Typically a garage job — get quotes before committing.

Does mileage affect the Sl MOT pass rate?

0-30k 94.1%
30-60k 88.4%
60-90k 79.1%
90-120k 100.0%

Pass rate by odometer reading. Bar lengths start at 71% so small gaps stay visible.

Regional pass rates for the Sl

Region Tests Pass rate
South East 360 91.9%
East of England 162 93.2%
South West 156 89.1%
Yorkshire 116 91.4%
West Midlands 110 92.7%
East Midlands 86 94.2%
Scotland 86 88.4%
North West 83 94.0%
London 53 96.2%
Wales 36 88.9%
North East 34 97.1%

Regions come from the postcode area recorded at the test station. Areas on region borders are assigned to the region with the majority of their population.

What fails a 2018 Sl

Everything a tester recorded on this vehicle, grouped into the inspection sections that produced it. The notch on each bar is the national share, so you can see at a glance whether this car is unusual or just ordinary.

Tyres 56.3%
+36.5 pts vs national national 19.8% Compare tyre prices
Brakes 11.4%
−9.5 pts vs national national 20.9% Price brakes parts
Suspension 8.6%
−12.4 pts vs national national 21.0% Price suspension parts
Visibility 5.9%
+0.9 pts vs national national 5.0% Order bulbs & wipers
Show the other 6 fault categories
  • Lamps & electrics 4.8%
  • Advisories 4.3%
  • Road wheels 3.2%
  • Identification 3.0%
  • Emissions & leaks 0.9%
  • Steering 0.7%

Shares are of every item recorded on 2018 Mercedes-Benz Sl tests — a composition, so they add to 100% across all sections, not per test.

A test can record several items, so these percentages do not add up to 100%. The exact strings, with prices, are in the full DVSA record at the bottom of this page.

Before your test

Three checks worth doing on a 2018 Sl

These are not generic tips — they are the faults recorded most often on this exact model, rewritten as things you can check yourself. All three take about ten minutes and cost nothing.

  1. Check the windscreen 1.6% of tests

    “windscreen damaged”

    Check the driver’s side of the screen within the swept area for chips and cracks; anything larger than 10mm in the driver’s central view is a fail. Most chips can be resin-repaired for far less than a new screen.

  2. Check the suspension joints 0.9% of tests

    “ball joint excessively worn”

    With the car parked on level ground, rock the top of each front wheel in and out while someone watches the suspension arm. Clunks, or rubber boots split and greasy, are what testers record here.

  3. Check the lights 0.4% of tests

    “headlamp aim too low”

    Switch everything on and walk round the car: both headlamps on dip and main, every indicator, both brake lights, reverse, fog and the two number-plate lamps. A bulb is a few pounds and a five-minute job.

Shares are the proportion of tests on this vehicle that recorded the item, so they overlap: one test can record several.

What it costs to get a 2018 Sl through its MOT

Across the 10 items that are recorded most often on this model, the average repair comes to £45–£106 — and 5% of those repairs are parts that cost under £30.

Average repair across the 10 common items
£45–£106
Cheapest common item: wipers blade defective
£8–£22
Dearest common item: windscreen damaged
£80–£200
Common items a careful owner can do at home
80%
Repairs that still cost under £30
5%

Estimates from typical UK parts prices, weighted by how often each item appears in 1,283 MOT tests on this vehicle. They exclude diagnostics, retest fees and garage labour where the part is a DIY fit, and they are not figures from the DVSA dataset. Older and higher-mileage examples cost more than the average. How these estimates are built → · All MOT repair costs → · Cheapest cars to put through a test →

Every year of the Sl, side by side

22 model years on record, from 2000 to 2021. Across them the pass rate runs from 84.9% to 93.7% — a spread of 8.8 points. The bar under each year is the item that failed it most often.

  1. 2000 86.5% ball joint dust cover severely…
  2. 2001 87.4% ball joint dust cover severely…
  3. 2002 85.2% ball joint dust cover severely…
  4. 2003 85.2% ball joint dust cover severely…
  5. 2004 86.7% windscreen damaged but not…
  6. 2005 86.1% coil spring fractured or broken
  7. 2006 85.4% coil spring fractured or broken
  8. 2007 85.5% coil spring fractured or broken
  9. 2008 86.7% coil spring fractured or broken
  10. 2009 85.3% coil spring fractured or broken
  11. 2010 84.9% windscreen damaged but not…
  12. 2011 88.3% coil spring fractured or broken
  13. 2012 86.2% has a cut in excess of the…
  14. 2013 86.2% malfunction indicator lamp…
  15. 2014 88.8% has a cut in excess of the…
  16. 2015 89.6% windscreen damaged but not…
  17. 2016 91.4% has a cut in excess of the…
  18. 2017 92.2% windscreen damaged but not…
  19. 2018 92.0%
    windscreen damaged but not…
  20. 2019 93.5% has a cut in excess of the…
  21. 2020 93.7% has a cut in excess of the…
  22. 2021 88.5% has a cut in excess of the…

Colour is the pass rate on a fixed scale, so a block means the same thing on any model. Each year links to its own page with the full fault breakdown.

Compare the 2018 Mercedes-Benz Sl with another year

The raw pass rate mostly measures age. The year comparison adds the like-for-like figure, the mileage bands and the repair bill.

Compare 2018 with another year →

Compare two different cars instead →

Other 2018 cars with a similar record

Closest pass rates among 2018 cars with at least 2,000 tests, so a small sample cannot flatter itself into the list. See the full rankings: best and worst MOT pass rates.

The full DVSA record for the 2018 Mercedes-Benz Sl 10 failure items · 6 advisories · 10 inspection categories · mileage brackets · all of it in the page, none of it above the fold

Every inspection category

Shares of the 556 individual items recorded on this vehicle, and the same share across all cars nationally. A single test can record several items, so a row is not a percentage of tests.

Category Items This car Nationally Difference
Tyres 316 56.30% 19.76% +36.54
Brakes 64 11.40% 20.89% −9.49
Suspension 48 8.60% 20.98% −12.38
Visibility 33 5.90% 4.97% +0.93
Lamps, reflectors and electrical equipment 27 4.80% 12.21% −7.41
Non-component advisories 24 4.30% 4.18% +0.12
Road Wheels 18 3.20% 0.75% +2.45
Identification of the vehicle 17 3.00% 1.76% +1.24
Noise, emissions and leaks 5 0.90% 5.52% −4.62
Steering 4 0.70% 2.57% −1.87

The exact failure items, in the tester's words

Share of the 1,283 tests on this vehicle that recorded each item
Recorded item Severity Tests Est. cost Part
Windscreen damaged but not adversely affecting driver's view Visibility Minor 1.6% £80–200 Windscreen →
Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres Major 1.3% £45–95 Tyres →
Has a bulge, caused by separation or partial failure of its structure Tyres Major 1.1% £45–95 Tyres →
Ball joint excessively worn Suspension Major 0.94% £18–45 Ball Joint →
Has ply or cords exposed Tyres Major 0.70% £45–95 Tyres →
Has a lump, caused by separation or partial failure of its structure Tyres Major 0.39% £45–95 Tyres →
Headlamp aim too low Lamps, reflectors and electrical equipment Rectified 0.39% £30–80 Headlight Alignment →
Registration plates does not conform to the specified requirements Identification of the vehicle Major 0.39% £20–80 Replacement Service Parts →
Wipers blade defective Visibility Minor 0.39% £8–22 Wiper Blade →
Tyre pressure monitoring system malfunctioning or obviously inoperative Tyres Major 0.23% £45–95 Tyres →

Severity is as recorded: Major and Dangerous fail the test outright; Minor and Advisory do not. Costs are estimates from typical UK parts prices — see how they are built.

What testers noted without failing the car

Advisories are the early warnings — the same parts a year or two before they fail. Reading them is how you tell a car that has been maintained from one that has been patched.

Items recorded as advisory on this vehicle
Recorded item Severity Tests Est. cost
Has a tear, caused by separation or partial failure of its structure Tyres Advisory 7.8% £45–95
Tread depth below requirements of 1.6mm Tyres Advisory 6.8% £45–95
Has a cut in excess of the requirements deep enough to reach the ply or cords Tyres Advisory 3.0% £45–95
Brake pads less than 1.5 mm thick Brakes Advisory 2.8% £18–45
Ball joint excessively worn Suspension Advisory 1.9% £18–45
Has a bulge, caused by separation or partial failure of its structure Tyres Advisory 1.4% £45–95

Pass rate by mileage

Mileage Tests Pass rate Median odometer
0-30k 882 94.1% 17,462 mi
30-60k 353 88.4% 39,302 mi
60-90k 43 79.1% 68,574 mi
90-120k 5 100.0% 101,586 mi

Source: 1,283 recorded tests on this vehicle-year. Every row above is recomputed from the same DVSA extract as the rest of the page — see the methodology.

2018 Sl MOT questions

What is the MOT pass rate for a 2018 Mercedes-Benz Sl?

92.0% of the 1,283 2018 Mercedes-Benz Sl tests in this dataset passed, against a national average of 87.9% for cars first used in 2018. First-attempt pass rate: 91.4%.

What are the most common MOT failures on a 2018 Mercedes-Benz Sl?

The three most recorded items are windscreen damaged but not adversely affecting driver's view (1.64%), has a cut in excess of the requirements deep enough to reach the ply or cords (1.33%), has a bulge, caused by separation or partial failure of its structure (1.09%). Percentages are the share of tests on this vehicle that recorded the item.

Does mileage affect the 2018 Mercedes-Benz Sl MOT pass rate?

Yes. Cars under 30,000 miles passed 94.1% of the time, falling to 100.0% for those over 120,000 miles. The median 2018 Mercedes-Benz Sl in this dataset had covered 22,948 mi.

Does the season affect the 2018 Mercedes-Benz Sl MOT pass rate?

Tests recorded in the winter months (October–March) passed 91.1% of the time; summer months (April–September) passed 92.8%. Brakes, tyres and lights are tested harder in bad weather, but the difference is small on most models.