Should I check the MOT history before buying a 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A?

Yes. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. A full MOT history analysis will highlight patterns that a single test result won't reveal.

What corrosion should I look for when inspecting a 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A?

Check brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that is expensive to fix and can fail an MOT.

How are tyres and brakes typically on a 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A?

Tyres and brakes are the most common advisory items on vehicles of this age. Budget for replacement if they are near the limit, and factor this into your offer price.

Is the 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A reliable?

Based on MOT data from 166 vehicles, the 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A has a first-time MOT pass rate of 94.6%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

Do I need an HPI check when buying a 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A?

Yes. The MOT history will not show outstanding finance, insurance write-offs, or stolen status. An HPI check covers these areas and should be part of any used car purchase.

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Mercedes Benz G 400 Amg Line Prem + D 4m A (2021)

166 real MOT outcomes analysed • 94.6% first-time pass rate

2021 Mercedes Benz G 400 Amg Line Prem + D 4m A

CarHunch analysed 166 real MOT records for the 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
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This G 400 is a significant reliability concern: just 54.1% pass first time against the UK average of 80%, meaning nearly half fail their MOT. Dangerous defects are rare at 2.4%, but the weak pass rate points to systemic issues rather than one-off problems.

These cars are still relatively young at around 32,000 miles median, so the high failure rate isn't mileage-related wear—it's inherent to the model. With only 0.11 failures per vehicle on average but 0.5 advisories, you're looking at minor issues that accumulate and trip up MOTs rather than catastrophic failures. If you're considering this model, budget for pre-purchase inspection by a Mercedes specialist and factor in regular remedial work to prepare for MOT season.

We have limited data for the 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A — treat the figures below as indicative rather than definitive.

First-time pass

94.6%

UK average ~80%

Better than average

Dangerous (ever)

2.4%

At least once in MOT history

Check this vehicle

Avg failures / car

0.11

Over 1.7 tests on record

Low

Typical mileage

32k

Middle half: 23k–46k

For context

These stats describe 166 vehicles as a group. The specific vehicle you're looking at could be the one good example or the one outlier. Run its registration to find out.

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Spot recurring advisories, hidden issues, and how it compares to 166 Mercedes Benz G 400 Amg Line Prem + D 4m A cars.

Before you buy a 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A

Based on MOT data from 166 vehicles — here's what to check.

📋 Check the full MOT history. 2.4% of these vehicles have had a dangerous defect recorded - recurring advisories often signal problems years before they become failures.
Search the reg on CarHunch for the full MOT history, reliability stats and a free AI-powered analysis of that exact vehicle.
🔍 Brake pipes, sills and subframes are the key areas on a vehicle this age — structural rust is hard to spot without getting underneath. A mechanic will check all of this before you commit, and give you a concrete basis to negotiate on price. Inspection →
📄 Outstanding finance, insurance write-offs and clocking won't appear in the MOT records — a dedicated history check covers all of this. Our link gets you 20% off automatically. History Get 20% off via CarHunch

Mileage Distribution

Most 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A vehicles sit in the blue band. If the vehicle you're looking at is outside it, it's either unusually low or high mileage for its age.

31,966

typical

23,079

low mileage

46,179

high mileage

Half of all 2021 Mercedes Benz G 400 Amg Line Prem + D 4m A vehicles fall between 23,079 and 46,179 miles.

Is the mileage you're seeing normal?

✓ Under 23,079 miles — lower than most. Could be great, or could be a vehicle that rarely moved. Check test frequency and mileage progression in the MOT history.

✓ 23,079–46,179 miles — normal for age. This is where most 2021 Mercedes Benz G 400 Amg Line Prem + D 4m As sit.

⚠ Over 62,341 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

MOT History Averages

1.7

Avg MOT tests per vehicle

0.11

Avg failures per vehicle

0.5

Avg advisories per vehicle

Other model years — Mercedes Benz G 400 Amg Line Prem + D 4m A: All G 400 Amg Line Prem + D 4m A years → Which year to buy? →

2022 2023

Or browse all models: Mercedes Benz →

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