Used Mercedes-Benz R-Class buying guide

In 2025, Mercedes-Benz R-Class cars passed 72.2% of 1,761 initial MOT tests, in line with the 72.3% UK average. Here is where it fails and what to check before you buy.

Looking at a specific R-Class? Check its finance, write-off, stolen, mileage and keeper history. £15, no account needed.

Mercedes-Benz R-Class MOT record in brief

Initial MOT tests in 2025, retests excluded.

72.2%

Mercedes-Benz R-Class pass rate

72.3%

UK average, all cars

−0.1

percentage points below average

Ranked on pass rate the R-Class sits 310th of 575 models in the data. Mercedes-Benz as a brand averaged 77.1%, so this model runs 4.8 points behind its own brand.

A pass rate is not a reliability score. The full Mercedes-Benz R-Class MOT record has the pass rate by age, every common failure and how the R-Class compares with similar cars.

R-Class fuel types

Diesel made up 91.4% of Mercedes-Benz R-Class MOT tests in 2025, against 39.3% across all models in this data. Almost every used example you look at will be a diesel.

Where the R-Class fails its MOT

Where Mercedes-Benz R-Class cars that failed their 2025 MOT were marked down, as a share of all recorded failure items.

  • Brakes28%
  • Lamps, reflectors and electrical equipment26.3%
  • Body, chassis, structure10.6%
  • Tyres8.8%
  • Noise, emissions and leaks8.5%
  • Suspension7.5%

The specific items testers recorded most often were joints constant velocity boot split or insecure, no longer prevents the ingress of dirt (7.6%), position lamp not working (7%) and rigid brake pipes excessively corroded (5.5%). See every common R-Class MOT failure.

These are DVSA failure records across every Mercedes-Benz R-Class that failed, not a claim that every R-Class has these problems.

What should you check when buying a used R-Class?

The areas above, most common first, and what an MOT tester looks at in each.

1

Brakes

Make sure the pedal feels firm, the car stops in a straight line, the handbrake holds on a slope and no brake warning light is showing. 28% of R-Class failure items.

2

Lamps, reflectors and electrical equipment

Walk round with every light on: headlights, brake lights, indicators, fog lights and the number plate lamp. Check no warning lights stay on after starting. 26.3% of R-Class failure items.

3

Body, chassis, structure

Look underneath and along the sills for corrosion, and check for damaged or poorly repaired panels. 10.6% of R-Class failure items.

4

Tyres

Check tread depth across the full width of every tyre (the legal minimum is 1.6mm), and look for cuts, bulges and uneven wear. 8.8% of R-Class failure items.

5

Noise, emissions and leaks

Listen for a blowing exhaust, watch for smoke on start-up and look under the car for oil or fluid leaks. 8.5% of R-Class failure items.

None of this replaces the car's own record. Run a free MOT history check on the registration to see every test, advisory and recorded mileage for that car.

What the MOT record doesn't tell you

Knowing Mercedes-Benz R-Class failures cluster around brakes and lamps, reflectors and electrical equipment tells you what to inspect. It tells you nothing about whether the car is safe to buy. An MOT does not show money still owed on the car, a write-off, a theft record or a clocked odometer.

Check the exact R-Class you are looking at. One £15 report, instant results, backed by a £30,000 data guarantee. More on the Mercedes-Benz history check.

  • Outstanding finance
  • Write-off records
  • Stolen markers
  • Mileage history
  • Previous keepers

Used Mercedes-Benz R-Class FAQs

Is the Mercedes-Benz R-Class reliable?

MOT data does not measure reliability. It records whether a car met the roadworthiness standard on the day of its test. What it does show is a 72.2% first-time pass rate for the Mercedes-Benz R-Class across 1,761 tests in 2025, in line with the 72.3% average for all cars.

What should I check before buying a used Mercedes-Benz R-Class?

On the car itself, start with the areas it most often fails on: brakes, lamps, reflectors and electrical equipment and body, chassis, structure. Then check the individual car's history: outstanding finance, insurance write-off records, stolen markers, mileage and previous keepers. None of these appear in the MOT record or on the V5C.

How do I check a Mercedes-Benz R-Class's history?

Enter the registration of the specific car. A Carpeep car history check reports outstanding finance, write-off category, stolen markers, mileage history, previous keepers, MOT and tax status, import and export markers and scrapped status in one £15 report.

MOT figures are aggregated from the DVSA MOT Anonymised data set for 2025 (class 4 initial tests, retests excluded), licensed under the Open Government Licence v3.0. MOT results describe roadworthiness at test, not mechanical reliability.