Mercedes-Benz SL-Class Reliability: MOT Pass Rate by Year & Engine

Verdict

The Mercedes-Benz SL-Class passes its MOT first time on 82.2% of tests, 15.9 points higher than a typical car of the same age and mileage (66.3%). That puts it ahead of 99% of cars on UK roads once age and mileage are taken into account.

Of its engines, the 5.0 Petrol does best (beats 99%) and the 3.5 Petrol worst (beats 98%).

Better than average on suspension, lights & electrics, brakes.

Watch these weak spots

Ball joint dust covers1.5×as often as a typical car

MOT pass rate by age

First-time pass rate at each MOT by the car’s age in years.

Mercedes-Benz SL-ClassTypical car, same age & mileage

Best and worst years

By year of first registration, ranked against all cars on UK roads after adjusting for age and mileage. Green = better than half of cars.

Beats 95%

Beats 93%

Beats 99%

Beats 98%

Beats 98%

Beats 99%

Beats 99%

Beats 100%

Beats 99%

Beats 99%

Beats 100%

Beats 100%

Beats 99%

Beats 99%

Beats 99%

Beats 97%

Beats 95%

Beats 97%

Beats 95%

Beats 93%

Beats 96%

Beats 96%

Beats 89%

Beats 94%

Beats 87%

Beats 80%

Engines

All years, most common first. Grades compare each car with cars of the same age and mileage (A = best 20% of cars on UK roads, E = worst 20%), so an older or higher-mileage car can grade above one with a higher pass rate.

Engine	Years	Tests	Pass rate	Rank	Grade
3.5 Petrol	2006–2014	32,769	82.9%	Beats 98%	A
5.0 Petrol	1995–2006	29,732	80.3%	Beats 99%	A
3.7 Petrol	2003–2006	25,264	79.1%	Beats 99%	A
3.2 Petrol	1994–2001	22,373	79.4%	Beats 99%	A
3.0 Petrol	2014–2019	17,605	89.6%	Beats 93%	A
5.4 Petrol	2002–2005	12,080	83.7%	Beats 100%	A
5.5 Petrol	2007–2013	3,951	85.4%	Beats 99%	A
4.7 Petrol	2013–2015	3,555	86.8%	Beats 93%	A
2.8 Petrol	1994–1997	2,549	78.7%	Beats 97%	A

Where it fails

Each area compared with a typical car of the same age and mileage, in points of pass rate. Tap or hover an area to see what to check.

Better than typicalTypicalWorse than typical

Tyres: 4.6% of tests fail on tyres, against 5.4% for a typical car of the same age and mileage. Check the tread on every tyre, including the inner edge, and look for cuts or bulges.

Every MOT area

Share of tests failing on each area, against a typical car of the same age and mileage (black line).

Suspension

5.1% vs 11.2%

Lights & electrics

4.9% vs 14.7%

Tyres

4.6% vs 5.4%

Brakes

3.7% vs 9.2%

Visibility

2.1% vs 6.2%

Emissions & leaks

1.8% vs 4.8%

Seat belts & airbags

0.9% vs 1.9%

Body & structure

0.7% vs 5.8%

Steering

0.7% vs 2.5%

Wheels

0.5% vs 0.3%

Buying one or MOT due? Check these

Tyre damage & cracking
Look for cuts, bulges and cracking on both sidewalls of every tyre.
Headlight aim
Park facing a wall at night: both dipped beams should sit level and dip to the left.
Coil springs
Look behind each wheel for a snapped coil (often the bottom one) and listen for clunks over bumps.
Suspension ball joints
Listen for knocks over speed bumps and feel for wandering or vague steering.
Windscreen wipers
Test the washers and wipers: a cheap fix, but a very common MOT fail.
Shock absorbers
Push down hard on each corner: it should rebound once and settle. Look for oily dampers.

Pass rate by mileage

First-time pass rate by mileage at the test.

Mercedes-Benz SL-ClassTypical car

Most common MOT failures

Item	This car	Typical	vs typical
Tyre damage & cracking	3.6%	3.1%	1.2×
Headlight aim	1.4%	4.1%	0.3×
Coil springs	1.3%	2.3%	0.6×
Suspension ball joints	1.2%	1.4%	0.9×
Windscreen wipers	1.0%	3.2%	0.3×
Brake pipes	1.0%	1.8%	0.6×
Ball joint dust covers	0.9%	0.6%	1.5×
Windscreen washers	0.9%	2.7%	0.3×
Shock absorbers	0.8%	1.0%	0.8×
Tyre tread depth	0.8%	2.0%	0.4×

Specific defects found

Tester wording for the most frequent failure items, per 1,000 tests.

Defect	per 1,000
A tyre seriously damaged	22.6
A suspension pin, bush or joint excessively worn	17.8
The aim of a headlamp is not within limits laid down in the requirements	14.3
A tyre cords visible or damaged	12.9
A spring or spring component fractured or seriously weakened	12.8
A suspension joint dust cover missing or no longer prevents the ingress of dirt etc	9.9
Wiper blade missing or obviously not clearing the windscreen	9.4
Brake pipe damaged or excessively corroded	9.4

Check another car

Pick a make and model to see its MOT pass rate, best and worst years and weak spots.

Every year and engine

Tap a year to see its engines. Grades compare each car with cars of the same age and mileage (A = best 20% of cars on UK roads, E = worst 20%), so an older or higher-mileage car can grade above one with a higher pass rate.

2019 Mercedes-Benz SL-Class1 engine91.6% passA

Engine	Tests	Pass rate	Rank	Grade
3.0 Petrol	1,172	91.6%	Beats 80%	A

2018 Mercedes-Benz SL-Class1 engine91.2% passA

Engine	Tests	Pass rate	Rank	Grade
3.0 Petrol	1,801	91.2%	Beats 87%	A

2017 Mercedes-Benz SL-Class1 engine91.0% passA

Engine	Tests	Pass rate	Rank	Grade
3.0 Petrol	3,132	91.0%	Beats 94%	A

2016 Mercedes-Benz SL-Class1 engine88.9% passA

Engine	Tests	Pass rate	Rank	Grade
3.0 Petrol	4,476	88.9%	Beats 89%	A

2015 Mercedes-Benz SL-Class2 engines89.2% passA

Engine	Tests	Pass rate	Rank	Grade
3.0 Petrol	5,436	89.1%	Beats 96%	A
4.7 Petrol	1,057	89.8%	Beats 96%	A

2014 Mercedes-Benz SL-Class3 engines87.1% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	5,937	86.9%	Beats 96%	A
3.0 Petrol	1,588	87.5%	Beats 94%	A
4.7 Petrol	1,052	87.2%	Beats 95%	A

2013 Mercedes-Benz SL-Class3 engines84.8% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	6,983	84.4%	Beats 92%	A
5.5 Petrol	1,483	87.2%	Beats 97%	A
4.7 Petrol	1,446	84.2%	Beats 88%	A

2012 Mercedes-Benz SL-Class1 engine84.0% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	2,043	84.0%	Beats 95%	A

2011 Mercedes-Benz SL-Class1 engine83.5% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	1,501	83.5%	Beats 97%	A

2010 Mercedes-Benz SL-Class1 engine79.9% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	1,977	79.9%	Beats 95%	A

2009 Mercedes-Benz SL-Class1 engine80.0% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	2,893	80.0%	Beats 97%	A

2008 Mercedes-Benz SL-Class2 engines82.1% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	4,477	81.6%	Beats 99%	A
5.5 Petrol	1,271	83.8%	Beats 99%	A

2007 Mercedes-Benz SL-Class2 engines81.6% passA

Engine	Tests	Pass rate	Rank	Grade
3.5 Petrol	4,718	80.8%	Beats 99%	A
5.5 Petrol	1,197	84.9%	Beats 100%	A

2006 Mercedes-Benz SL-Class3 engines80.2% passA

Engine	Tests	Pass rate	Rank	Grade
3.7 Petrol	2,389	79.4%	Beats 99%	A
3.5 Petrol	2,240	80.1%	Beats 99%	A
5.0 Petrol	1,253	82.0%	Beats 99%	A

2005 Mercedes-Benz SL-Class3 engines81.5% passA

Engine	Tests	Pass rate	Rank	Grade
3.7 Petrol	6,541	79.5%	Beats 99%	A
5.0 Petrol	2,444	84.9%	Beats 100%	A
5.4 Petrol	1,058	85.8%	Beats 100%	A

2004 Mercedes-Benz SL-Class3 engines81.3% passA

Engine	Tests	Pass rate	Rank	Grade
3.7 Petrol	9,187	79.2%	Beats 99%	A
5.0 Petrol	4,521	83.3%	Beats 100%	A
5.4 Petrol	2,904	84.7%	Beats 100%	A

2003 Mercedes-Benz SL-Class3 engines80.0% passA

Engine	Tests	Pass rate	Rank	Grade
5.0 Petrol	9,082	79.2%	Beats 99%	A
3.7 Petrol	7,147	78.4%	Beats 99%	A
5.4 Petrol	5,665	83.2%	Beats 100%	A

2002 Mercedes-Benz SL-Class2 engines79.8% passA

Engine	Tests	Pass rate	Rank	Grade
5.0 Petrol	6,829	78.8%	Beats 99%	A
5.4 Petrol	2,453	82.7%	Beats 100%	A

2001 Mercedes-Benz SL-Class1 engine82.3% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	1,772	82.3%	Beats 100%	A

2000 Mercedes-Benz SL-Class1 engine80.2% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	3,214	80.2%	Beats 99%	A

1999 Mercedes-Benz SL-Class1 engine81.2% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	3,178	81.2%	Beats 99%	A

1998 Mercedes-Benz SL-Class2 engines79.0% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	3,924	78.9%	Beats 99%	A
5.0 Petrol	1,486	79.2%	Beats 98%	A

1997 Mercedes-Benz SL-Class3 engines79.3% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	3,413	77.9%	Beats 97%	A
5.0 Petrol	1,419	80.3%	Beats 99%	A
2.8 Petrol	1,046	82.2%	Beats 99%	A

1996 Mercedes-Benz SL-Class2 engines80.4% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	2,834	80.3%	Beats 99%	A
5.0 Petrol	1,394	80.8%	Beats 99%	A

1995 Mercedes-Benz SL-Class2 engines75.8% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	2,534	76.1%	Beats 94%	A
5.0 Petrol	1,304	75.3%	Beats 91%	A

1994 Mercedes-Benz SL-Class2 engines77.8% passA

Engine	Tests	Pass rate	Rank	Grade
3.2 Petrol	1,504	79.3%	Beats 97%	A
2.8 Petrol	1,503	76.2%	Beats 92%	A

FAQ

What is the Mercedes-Benz SL-Class MOT pass rate?

82.2% of MOT tests on the Mercedes-Benz SL-Class were passed first time, based on 149,878 tests between 2018 and 2026 of cars first registered 1994–2019. A typical car of the same age and mileage passes 66.3% of the time.

Is the Mercedes-Benz SL-Class reliable?

On MOT results it rates A (excellent): it passes first time more often than a typical car of the same age and mileage and does better than 99% of cars on UK roads. MOT results cover safety and emissions items, not every kind of breakdown.

Which Mercedes-Benz SL-Class engine is best?

Across all years, the 5.0 Petrol does best: it beats 99% of cars on UK roads. The 3.5 Petrol does worst: it beats 98%.

What are the most common MOT failures on the Mercedes-Benz SL-Class?

The most common failure items are tyre damage & cracking, headlight aim, coil springs. Compared with similar cars, ball joint dust covers comes up 1.5× as often.

How we calculate this. We use official MOT results for cars tested in Great Britain from 2018 to 2026. Each car is compared with typical cars of the same age and mileage, so old and new cars are judged fairly; “pts” are percentage points above or below them. Differences also reflect how cars are used and maintained, not only how they are built.

Mercedes-Benz SL-Class reliability

Verdict

Watch these weak spots

MOT pass rate by age

Best and worst years

Engines

Where it fails

Every MOT area

Buying one or MOT due? Check these

Pass rate by mileage

Most common MOT failures

Specific defects found

Every year and engine

FAQ