2017 Mercedes-Benz CLS MOT pass rate: 83.3% (4,439 tests)

2017-registered Mercedes-Benz CLSs passed 83.3% of 4,439 MOT tests in 2023–2025 — broadly in line with same-age cars (84.0%). This is one of the lower-scoring CLS years after correcting for vehicle age — inspect the individual car carefully.

83.3%Pass rate, 2017 cars

99.2Age-adjusted index (100 = average)

4,439Tests analysed

55,712 miMedian mileage at test

84.1% / 83.2%Petrol vs diesel pass rate

Is the 2017 CLS getting worse?

Pass rate of 2017-registered cars across recent test years:

Test year	Pass rate
2023	85.2% -0.6 vs same-age
2024	82.3% -1.6 vs same-age
2025	82.2% -0.1 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 2017 CLS

#	System	Defects recorded	Share
1	Tyres	617	50.7%
2	Brakes	189	15.5%
3	Suspension	150	12.3%
4	Noise, emissions and leaks	83	6.8%
5	Road Wheels	70	5.8%
6	Lamps, reflectors and electrical equipment	48	3.9%

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 (this page)	4,439	83.3%	-0.8 pts	55,712
2018	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 2017 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 2017 Mercedes-Benz CLS reliable?

2017-registered examples passed 83.3% of their MOT tests (4,439 tests, 2023–2025), -0.8 points versus all UK cars registered in the same year. At roughly 9 years old with a median 55,712 miles, condition now varies car by car — always check the individual MOT history.

What mileage is too high for a 2017 CLS?

The median tested example shows 55,712 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.