Mercedes Benz Glc 300 Amg Line Prem + D 4m A (2021)

950 real MOT outcomes analysed • 91.8% first-time pass rate

2021 Mercedes Benz Glc 300 Amg Line Prem + D 4m A

CarHunch analysed 950 real MOT records for the 2021 Mercedes Benz Glc 300 Amg Line Prem + D 4m A. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.

The 2021 Mercedes-Benz GLC 300 AMG Line is a strong performer in the MOT bay, with a 91.8% first-time pass rate that comfortably beats the UK average of 80%—a real mark of reliability at this age. Only 8.3% of vehicles have ever recorded a dangerous defect, which is well below concern threshold and suggests these cars are safe bets structurally.

At 31,150 miles median (33,612 average), these vehicles are running light for their age, which partly explains the clean record. The typical car racks up just 0.2 failures and 1.6 advisories per test, pointing to predictable wear items rather than systemic weak spots—the takeaway is that you're buying a well-engineered diesel SUV where maintenance trumps luck.

Generally reliable 11.8% above UK average
91.8%
pass MOT first time
UK average: ~80%
31,150
typical mileage
24,616–40,290 middle half
8.3%
ever had a dangerous defect
recorded at any MOT
0.2
avg MOT failures per car
over 2.3 tests on record

What to check before buying a 2021 Mercedes Benz Glc 300 Amg Line Prem + D 4m A

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 Glc 300 Amg Line Prem + D 4m A

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

CarHunch may earn a small commission if you buy via these links — at no extra cost to you.

Mileage Distribution

Most 2021 Mercedes Benz Glc 300 Amg Line Prem + D 4m A 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.

24,616
low mileage
31,150
typical
40,290
high mileage

Half of all 2021 Mercedes Benz Glc 300 Amg Line Prem + D 4m A vehicles fall between 24,616 and 40,290 miles.

MOT History Averages

2.3
Avg MOT tests per vehicle
0.2
Avg failures per vehicle
1.6
Avg advisories per vehicle

Found a specific Mercedes Benz Glc 300 Amg Line Prem + D 4m A?

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

UK

Other model years — Mercedes Benz Glc 300 Amg Line Prem + D 4m A:

2019 2020 2022 2023