Mercedes-Benz SLK: 72% pass.

54,075 tests of cars aged 3 and over passed first time 72% of the time in 2025. For cars of the same ages, 62% would be expected: 10 points better than that.

How it does as it ages.

01 / By age

Source: Anonymised MOT tests and results (Driver and Vehicle Standards Agency) Checked 4 Nov 2026, 13:37

Diesel
Age of car	Pass first time	All cars this age	Fixed at the station	Failed	Tests
8 years	81%	76%	2%	17%	304
9 years	79%	73%	2%	19%	2,311
10 years	77%	70%	2%	21%	3,305
11 years	73%	67%	2%	25%	3,225
12 years	71%	64%	3%	26%	3,236
13 years	68%	62%	3%	29%	762

Petrol
Age of car	Pass first time	All cars this age	Fixed at the station	Failed	Tests
8 years	91%	76%	2%	7%	151
9 years	86%	73%	2%	12%	970
10 years	83%	70%	2%	15%	1,455
11 years	79%	67%	2%	19%	1,376
12 years	78%	64%	3%	19%	2,190
13 years	76%	62%	2%	22%	3,257
14 years	73%	60%	2%	25%	1,861
15 years	69%	58%	3%	28%	2,291
16 years	68%	57%	3%	29%	2,671
17 years	68%	57%	4%	28%	3,366
18 years	67%	57%	4%	29%	3,299
19 years	68%	57%	4%	28%	3,837
20 years	66%	57%	4%	29%	4,113

Ages with fewer than 30 tests are left out. "All cars this age" is every make and model at that age, so you can see whether this one does better or worse than most.

A pass rate is the share of normal MOT tests a car passed first time, with no repair needed at the test station. A car that failed and was fixed on the spot is counted separately. Retests, aborted tests and other vehicles are left out.
The figures say how often cars of a kind pass, not how reliable or safe they are. Cars that are looked after better, or that are driven fewer miles, pass more often, and that differs by model. Groups of fewer than 30 tests are left out.
Make and model names are as DVSA records them, and a model can appear under more than one name.

More on Mercedes-Benz and costs.

02 / Related

Data sources

Anonymised MOT tests and results (Driver and Vehicle Standards Agency). Contains public sector information licensed under the Open Government Licence v3.0. MOT test results for cars, counted by make, model and age from DVSA's anonymised data. The counts are ours; DVSA does not endorse them.