MOT failure rate and common problems for the Mercedes-Benz Cls250, and how to check your own car by registration.
Updated 05 September 2026.
Mercedes-Benz Cls250 MOT failure rate
What a Mercedes-Benz Cls250 fails its MOT on, and the part that fixes each.
What it fails on, and why
This covers a range of smaller items, from a non-working horn to a warning light left on.
Suspension failures usually mean a worn or snapped coil spring, a leaking shock absorber, or play in a lower arm ball joint or bush. The tester checks for corrosion, fractures and excessive movement. A broken front spring is one of the most common failures on higher-mileage cars and is a straightforward replacement.
Tyres fail for tread below the 1.6mm legal limit across the central three-quarters, uneven or exposed-cord wear, or sidewall damage. The tester inspects all four; a single illegal tyre is a fail.
Lighting is the single most common MOT failure and the cheapest to put right. A blown headlight, brake-light or number-plate bulb, a cracked lens, or a headlamp beam that points too high or low will all fail. Most are a two-minute bulb swap.
Brake failures cover worn pads and discs, an imbalance between wheels, corroded or scored discs, or a binding caliper. Braking efficiency is measured on a rolling road, so a spongy or pulling brake shows up as a low reading.
The parts that fix each
If your car has just failed, you have 10 working days to fix the items and get a free partial retest. Confirm the exact fitment against your registration or VIN before buying.
Other models
Questions and answers
What is the MOT failure rate of the Mercedes-Benz Cls250?
It fails 18.0% of its MOT tests across the DVSA record, from 766 tests.
What do these cars fail their MOT on most?
The most common failure area is other, at 2.2% of this model's failures.