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MG B (1981)

709 real MOT outcomes analysed • 54.9% first-time pass rate

1981 MG B

CarHunch analysed 709 real MOT records for the 1981 MG B. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.

Below average reliability 25.1% below UK average
54.9%
pass MOT first time
UK average: ~80%
50,493
typical mileage
24,077–71,649 middle half
12.1%
ever had a dangerous defect
recorded at any MOT
1.85
avg MOT failures per car
over 7.8 tests on record

What to check before buying a 1981 MG B

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 MG B

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

Inspection ClickMechanic Have a qualified mechanic check this car before you commit to buying →

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Pass Rate by Fuel Type

Fuel type Vehicles Pass rate Avg failures
Petrol (99%) 702 54.5% 1.87
Other (1%) 7 90% 0.29

Mileage Distribution

Most 1981 MG B 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.

24,077
low mileage
50,493
typical
71,649
high mileage

Half of all 1981 MG B vehicles fall between 24,077 and 71,649 miles.

1981 MG B — Still on the Road

Numbers are declining — 58 vehicles still getting MOTs in 2025 (26% of peak).

222 58 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

7.8
Avg MOT tests per vehicle
1.85
Avg failures per vehicle
6.1
Avg advisories per vehicle

Most Common MOT Issues — 1981 MG B

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

  • 58.8%
    Exhaust emissions carbon monoxide content excessive
  • 36.2%
    Oil leak
  • 31.3%
    Oil leak, but not excessive
  • 28.9%
    Exhaust emissions hydrocarbon content excessive
  • 24.7%
    Windscreen washer provides insufficient washer liquid
  • 15.7%
    Offside Rear fog lamp not working
  • 15%
    Parking brake: efficiency below requirements
  • 13.8%
    Nearside Front Axle king pin has slight play in pin and/or bush

Data covers a 3-year window centred on 1981. Counts include advisories and failures.

Found a specific MG B?

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

UK

Other model years — MG B:

1980