Should I check the MOT history before buying a 2020 Mercedes Benz B?

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 2020 Mercedes Benz B?

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 2020 Mercedes Benz B?

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 2020 Mercedes Benz B reliable?

Based on MOT data from 2,658 vehicles, the 2020 Mercedes Benz B has a first-time MOT pass rate of 93.2%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

What are common problems with the 2020 Mercedes Benz B?

The most frequently recorded MOT issues on the 2020 Mercedes Benz B are: Nearside Front Tyre worn close to legal limit/worn on edge (25.2% of vehicles), Offside Front Tyre worn close to legal limit/worn on edge (25.1% of vehicles), Nearside Rear Tyre slightly damaged/cracking or perishing (13.8% of vehicles). These figures are based on actual MOT test records — search a specific registration on CarHunch to see its individual history.

Do I need an HPI check when buying a 2020 Mercedes Benz B?

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.

CarHunch

Get Started

Mercedes Benz B (2020)

2,658 real MOT outcomes analysed • 93.2% first-time pass rate

2020 Mercedes Benz B

CarHunch analysed 2,658 real MOT records for the 2020 Mercedes Benz B. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
Which year to buy? →

On this page

AI Analysis Reliability Overview Common Issues Check a Specific Reg Buyer's Checklist Pass Rate by Fuel Mileage Distribution Still on the Road MOT Averages Colour Breakdown Compare Models

The 2020 Mercedes-Benz B is a genuinely reliable car by UK standards, with a 93.2% first-time MOT pass rate that sits well above the 80% national average. Dangerous defects are uncommon at just 8.5% of vehicles, so safety concerns needn't deter buyers—and petrol and diesel variants perform almost identically (93.3% and 92.9% pass rates respectively).

These cars are running relatively low mileage for their age at a median of 20,792 miles, suggesting careful ownership, and when failures do occur they're rare at 0.3 per vehicle with modest advisory issues averaging 2.1. Before purchasing, have a pre-buy inspection focus on the suspension and electrical systems, as these typically flag advisories on this model, but overall you're looking at a low-maintenance option.

The 2020 Mercedes Benz B passes its MOT first time more often than most UK vehicles (93.2% vs ~80% average) — and when it does fail, it's usually something minor and cheap to fix.

⚠️ About 1 in 12 of these vehicles have had a dangerous MOT failure at some point — usually tyres or brakes, and often a one-off issue rather than a persistent problem. The group stats won't tell you which one you're looking at.

First-time pass

93.2%

UK average ~80%

Better than average

Dangerous (ever)

8.5%

At least once in MOT history

Check this vehicle

Avg failures / car

0.3

Over 3.5 tests on record

Low

Typical mileage

21k

Middle half: 14k–29k

For context

✅ Good baseline reliability. A 93.2% first-time pass rate puts this well above the UK average — it's a well-sorted vehicle in this age bracket.

🔧 Expect consumable spend. An average of 2.1 advisories per vehicle tells you wear items (tyres, brakes) get flagged regularly. Budget for them — they're not surprises.

🔍 The dangerous defect figure is real. Most are one-off tyre failures or brake issues — not structural problems. But it's exactly why checking the individual vehicle's history is essential, not optional.

These stats describe 2,658 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.

A solid choice — agree?

What tends to go wrong

Across 2,658 vehicles — figures show how many had each issue flagged at least once in their MOT history.

Tyre wear 25.2%

Nearside Front Tyre worn close to legal limit/worn on edge · Offside Front Tyre worn close to legal limit/worn on edge · Nearside Rear Tyre slightly damaged/cracking or perishing · …

Budget for a full set — on a vehicle this age, tyres are expected consumables. An inspection will confirm how much is left.

Brake wear 8.5%

Rear Brake pad(s) wearing thin · Front Brake pad(s) wearing thin · Front Brake disc worn, but not excessively

Ask the seller when brakes were last serviced. If they don't know, factor in the cost.

Other issues 5.3%

Nearside Rear Child Seat fitted not allowing full inspection of adult belt · Windscreen damaged but not adversely affecting driver's view

Lighting 3.2%

Supplementary restraint system warning lamp indicates a fault

Usually cheap to fix. Worth confirming all lights work before collecting.

Data covers a 3-year window centred on 2020.

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 2,658 Mercedes Benz B cars.

Before you buy a 2020 Mercedes Benz B

Based on MOT data from 2,658 vehicles — here's what to check.

📋 Check the full MOT history. 8.5% 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

Pass Rate by Fuel Type

Fuel type	Vehicles	Pass rate	Avg failures
Petrol (60%)	1,605	93.3%	0.29
Diesel (40%)	1,053	92.9%	0.31

Colour Breakdown

Based on 7,843 Mercedes Benz B vehicles registered in the UK — across all years. From DVLA registration records.

Grey 28.2%

2,214

Black 19.6%

1,541

Blue 16.2%

1,268

White 15%

1,179

Silver 14.5%

1,138

Red 6.4%

503

Mileage Distribution

Most 2020 Mercedes Benz B 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.

20,792

typical

13,500

low mileage

29,347

high mileage

Half of all 2020 Mercedes Benz B vehicles fall between 13,500 and 29,347 miles.

Is the mileage you're seeing normal?

✓ Under 13,500 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.

✓ 13,500–29,347 miles — normal for age. This is where most 2020 Mercedes Benz Bs sit.

⚠ Over 39,618 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2020 Mercedes Benz B — Still on the Road

Almost all 2020 Mercedes Benz Bs are still on the road.

Strong survival — 2,604 vehicles still getting MOTs in 2025, 100% of the peak.

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2023–2025.

MOT History Averages

3.5

Avg MOT tests per vehicle

0.3

Avg failures per vehicle

2.1

Avg advisories per vehicle

Other model years — Mercedes Benz B: All B years → Which year to buy? →

2019 2021 2022

Or browse all models: Mercedes Benz →

Compare with another model

See how the 2020 Mercedes Benz B stacks up against a rival.

A solid choice — agree?