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Mercedes Benz 420 (1987)

511 real MOT outcomes analysed • 74.2% first-time pass rate

1987 Mercedes Benz 420

CarHunch analysed 511 real MOT records for the 1987 Mercedes Benz 420. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.

Below average reliability 5.8% below UK average
74.2%
pass MOT first time
UK average: ~80%
115,307
typical mileage
85,821–147,328 middle half
18.8%
ever had a dangerous defect
recorded at any MOT
2.69
avg MOT failures per car
over 11.1 tests on record

What to check before buying a 1987 Mercedes Benz 420

Practical pre-purchase checks for this age and model.

  • 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
  • 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
  • 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
  • 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.

Before you buy a Mercedes Benz 420

MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.

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Pass Rate by Fuel Type

Fuel type Vehicles Pass rate Avg failures
Petrol (99%) 508 74.2% 2.7
Diesel (0%) 2 73.6% 3
LPG (0%) 1 50% 1

Mileage Distribution

Most 1987 Mercedes Benz 420 vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.

85,821
low mileage
115,307
typical
147,328
high mileage

Half of all 1987 Mercedes Benz 420 vehicles fall between 85,821 and 147,328 miles.

1987 Mercedes Benz 420 — Still on the Road

135 vehicles still getting MOTs in 2025 — 69% of the peak remain.

196 135 2014 2025

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2014–2025.

MOT History Averages

11.1
Avg MOT tests per vehicle
2.69
Avg failures per vehicle
11.1
Avg advisories per vehicle

Most Common MOT Issues — 1987 Mercedes Benz 420

Based on actual MOT test records for this model. Percentage shows how often each item appears across all vehicles in this cohort.

  • 36.7%
    Oil leak
  • 24.9%
    Oil leak, but not excessive
  • 24.4%
    Offside Rear Tyre worn close to the legal limit
  • 23.9%
    Exhaust emissions carbon monoxide content excessive
  • 23.6%
    Nearside Rear Tyre worn close to the legal limit
  • 20.2%
    Parking brake: efficiency below requirements
  • 19.7%
    Offside Front Tyre worn close to the legal limit
  • 18%
    Nearside Rear Brake pipe slightly corroded

Data covers a 3-year window centred on 1987. Counts include advisories and failures.

Found a specific Mercedes Benz 420?

Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.

UK

Other model years — Mercedes Benz 420:

1986 1988 1989 1990 1991