How reliable is the Mercedes-Benz 500 compared with other cars?

We do not publish a comparison for the Mercedes-Benz 500, because the cars of this model that have been tested do not cover a wide enough range of ages and mileages. Its raw pass rate is 82.4% across 904 tests, but comparing a raw rate between models mostly ranks them by how new they are rather than how good they are. The failure and advisory patterns further down the page are still drawn from real tests and are worth reading.

What is the most common MOT failure on a Mercedes-Benz 500?

The item recorded most often is "A suspension joint dust cover missing or no longer prevents the ingress of dirt etc", which appears in 17.7% of failed Mercedes-Benz 500 tests. Because one failed test can list several items, these shares do not add up to 100%.

What do testers most often warn about on a Mercedes-Benz 500?

The most common advisory is "Brake pipe damaged or excessively corroded", noted on 12.3% of all Mercedes-Benz 500 tests. An advisory is not a failure: it flags something that will likely need attention before the next test.

What mileage does a Mercedes-Benz 500 usually have at its MOT?

The average odometer reading recorded at test is 100,606 miles. This is the mileage across all tested examples of every age, not an annual figure, so treat it as a description of the fleet rather than a target for one car.

Model reliability file

Mercedes-Benz 500 MOT pass rate & common failures

From 904 recorded MOT tests of the Mercedes-Benz 500, published by DVSA.

Data updated 29 July 2026

Quick answer

Across 904 MOT tests, 82.4% of Mercedes-Benz 500 tests ended in a pass. This figure is not adjusted for age or mileage, so it is not a reliability ranking: the Mercedes-Benz 500 fleet does not yet cover a wide enough spread of ages and distances to compare it fairly against other models. Its most commonly recorded failure is suspension joint dust cover missing or no longer prevents the ingress of dirt etc, which appears in 17.7% of failed tests. Cars of this model average 100,606 miles on the odometer when tested.

At a glance

Recorded pass rate

82.4%unadjusted, not comparable904 tests

We are not publishing a ranking for the 500. The examples tested do not cover a wide enough spread of ages and mileages to compare it fairly, and an unadjusted pass rate mostly sorts models by how recently they were bought rather than how well they were built. The failure and advisory patterns below come from the same 904 tests and are worth reading on their own terms.

DVSA recorded wording

Most common failure items

Share of failed Mercedes-Benz 500 tests in which each item was recorded. One failed test often lists several items, so these do not sum to 100%.

1.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc17.7%
23 occurrencesSuspension joint dust cover missing or split explained
2.Significant brake effort recorded with no brake applied indicating a binding brake16.9%
22 occurrencesBrake binding or imbalanced across an axle explained
3.A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning13.8%
18 occurrencesLamp not working explained
4.Emissions levels exceed default limits10.8%
14 occurrencesEmissions above the permitted limit explained
5.An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning10.0%
13 occurrencesLamp not working explained
6.Stop lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning6.9%
9 occurrencesStop lamp not working explained
7.Wiper blade missing or obviously not clearing the windscreen6.2%
8 occurrencesWiper or washer not working properly explained
8.Brake pipe damaged or excessively corroded6.2%
8 occurrencesBrake pipe corroded explained
9.Audible warning inoperative5.4%
7 occurrencesHorn not working, or of the wrong type explained
10.A suspension joint dust cover missing or no longer prevents the ingress of dirt etc5.4%
7 occurrencesSuspension joint dust cover missing or split explained

Warnings without a failure

Most common advisories

Share of all Mercedes-Benz 500 tests carrying each advisory. The denominator differs from the failure list above because an advisory can be issued on a car that passed.

1.Brake pipe damaged or excessively corroded12.3%
111 testsBrake pipe corroded explained
2.Fluid leaking excessively and likely to harm the environment or to pose a safety risk to other road users10.4%
94 tests
3.A tyre seriously damaged10.2%
92 testsTyre damaged or deteriorated explained
4.A spring or spring component fractured or seriously weakened9.7%
88 testsRoad spring broken or fractured explained
5.Tyre tread depth not in accordance with the requirements9.0%
81 testsTyre worn close to the legal limit explained
6.Brake disc or drum excessively weakened, insecure or fractured4.1%
37 testsBrake disc worn, pitted or scored explained
7.A wheel bearing with excessive play4.0%
36 testsWheel bearing has excessive play or is rough explained
8.A suspension pin, bush or joint excessively worn3.8%
34 testsSuspension arm bush worn explained

What gets tested

The 500 fleet

Average mileage recorded at test: 100,606
Fuel mix of tested cars: Petrol99.3%

Check a specific Mercedes-Benz 500

A model average tells you the pattern. Its own MOT record tells you the car.

Compare within the range

Other Mercedes-Benz models

Mercedes-Benz A-Class — 73.3% adjusted
Mercedes-Benz C-Class — 77.0% adjusted
Mercedes-Benz E-Class — 78.5% adjusted
Mercedes-Benz GLA — 82.3% adjusted
Mercedes-Benz Vito — 71.0% adjusted
Mercedes-Benz GLC — 85.9% adjusted
All Mercedes-Benz models

Common questions

How reliable is the Mercedes-Benz 500 compared with other cars?: We do not publish a comparison for the Mercedes-Benz 500, because the cars of this model that have been tested do not cover a wide enough range of ages and mileages. Its raw pass rate is 82.4% across 904 tests, but comparing a raw rate between models mostly ranks them by how new they are rather than how good they are. The failure and advisory patterns further down the page are still drawn from real tests and are worth reading.
What is the most common MOT failure on a Mercedes-Benz 500?: The item recorded most often is "A suspension joint dust cover missing or no longer prevents the ingress of dirt etc", which appears in 17.7% of failed Mercedes-Benz 500 tests. Because one failed test can list several items, these shares do not add up to 100%.
What do testers most often warn about on a Mercedes-Benz 500?: The most common advisory is "Brake pipe damaged or excessively corroded", noted on 12.3% of all Mercedes-Benz 500 tests. An advisory is not a failure: it flags something that will likely need attention before the next test.
What mileage does a Mercedes-Benz 500 usually have at its MOT?: The average odometer reading recorded at test is 100,606 miles. This is the mileage across all tested examples of every age, not an annual figure, so treat it as a description of the fleet rather than a target for one car.

How this was worked out

Method and limits

Figures come from the DVSA anonymised MOT testing dataset, published under the Open Government Licence. Only class 4 initial tests are counted: retests are excluded so a car appears once, and abandoned tests are excluded entirely. No adjusted rate is shown because this model's tested examples do not cover enough of the national age and mileage range for standardisation to mean anything.

An MOT measures whether a car met a legal standard on the day. It is not a breakdown record, a service history or a running-cost estimate, and a pass rate is a property of a fleet rather than a prediction about one car.