2018 Mercedes-Benz CLS MOT pass rate: 83.9% (2,877 tests)

2018-registered Mercedes-Benz CLSs passed 83.9% of 2,877 MOT tests in 2023–2025 — 2.4 points worse than same-age cars (86.4%). This is one of the lower-scoring CLS years after correcting for vehicle age — inspect the individual car carefully.

83.9%Pass rate, 2018 cars

97.6Age-adjusted index (100 = average)

2,877Tests analysed

46,578 miMedian mileage at test

82.9% / 84.1%Petrol vs diesel pass rate

Is the 2018 CLS getting worse?

Pass rate of 2018-registered cars across recent test years:

Test year	Pass rate
2023	84.7% -3.4 vs same-age
2024	82.9% -3.3 vs same-age
2025	84.2% -0.6 vs same-age

The raw rate normally falls as cars age. The “vs same-age” figure compares this cohort with all UK cars registered in the same year, so normal ageing is not mistaken for a bad model year.

What fails on a 2018 CLS

#	System	Defects recorded	Share
1	Tyres	356	45.0%
2	Suspension	110	13.9%
3	Road Wheels	103	13.0%
4	Brakes	59	7.5%
5	Body, chassis, structure	39	4.9%
6	Noise, emissions and leaks	38	4.8%

All CLS years compared

Registration year	Tests	Pass rate	Vs same-age	Median mileage
2005	2,789	76.1%	+11.6 pts	104,734
2006	4,152	73.9%	+9.4 pts	117,940
2007	5,062	72.2%	+7.1 pts	119,870
2008	4,020	71.9%	+6.7 pts	119,584
2009	3,249	69.3%	+2.9 pts	111,070
2010	3,175	70.5%	+3.1 pts	109,564
2011	3,480	77.1%	+7.9 pts	98,474
2012	3,312	76.8%	+5.6 pts	95,192
2013	9,119	75.8%	+2.5 pts	93,640
2014	5,329	77.6%	+1.7 pts	83,360
2015	8,599	82.2%	+3.5 pts	77,897
2016	6,264	82.2%	+0.9 pts	66,704
2017	4,439	83.3%	-0.8 pts	55,712
2018 (this page)	2,877	83.9%	-2.4 pts	46,578
2019	3,212	84.1%	-4.3 pts	39,081

Weighing up which year to buy? See the full ranking: Mercedes-Benz CLS years to avoid.

Buying a 2018 CLS? Two checks first

Free MOT history checkThe exact car’s failures, advisories and mileage trail — sellers can’t edit it
Topdon OBD2 scannersTopdon diagnostic scanners with full-system readouts
XTOOL diagnostic toolsXTOOL code readers for petrol and diesel cars
Autel UK testersAutel professional-grade diagnostic testers

FAQs

Is a 2018 Mercedes-Benz CLS reliable?

2018-registered examples passed 83.9% of their MOT tests (2,877 tests, 2023–2025), -2.4 points versus all UK cars registered in the same year. At roughly 8 years old with a median 46,578 miles, condition now varies car by car — always check the individual MOT history.

What mileage is too high for a 2018 CLS?

The median tested example shows 46,578 miles. Anything far beyond that isn't automatically bad — a motorway-mile car with consistent service records often beats a low-mileage school-run car — but price accordingly and scrutinise the mileage trail for gaps or drops.

Source: DVSA Anonymised MOT tests and results, 2023–2025 extracts (96 million Class 4 initial tests; retests excluded). Only vehicles old enough for a routine first MOT are included. Age-adjusted figures compare the model-year cohort with all vehicles of the same registration year tested in the same calendar year. Contains public sector information licensed under OGL v3.0.