Should I check the MOT history before buying a 2018 Mercedes Benz B Class?

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 2018 Mercedes Benz B Class?

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 2018 Mercedes Benz B Class?

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.

How many 2018 Mercedes Benz B Class vehicles have had dangerous defects recorded?

23% of these vehicles have had a dangerous defect recorded. Search the registration on CarHunch — the full MOT history will show exactly what was flagged and whether it was resolved.

Is the 2018 Mercedes Benz B Class reliable?

Based on MOT data from 3,875 vehicles, the 2018 Mercedes Benz B Class has a first-time MOT pass rate of 89.9%, indicating generally reliable for its class. Always check the full MOT history of any specific vehicle before buying.

What are common problems with the 2018 Mercedes Benz B Class?

The most frequently recorded MOT issues on the 2018 Mercedes Benz B Class are: Offside Front Tyre worn close to legal limit/worn on edge (34.3% of vehicles), Nearside Front Tyre worn close to legal limit/worn on edge (33.4% of vehicles), Offside Rear Tyre slightly damaged/cracking or perishing (26.9% 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 2018 Mercedes Benz B Class?

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 B Class (2018)

3,875 real MOT outcomes analysed • 89.9% first-time pass rate

2018 Mercedes Benz B Class

CarHunch analysed 3,875 real MOT records for the 2018 Mercedes Benz B Class. Real test outcomes — pass rates, defect profiles, mileage data — from verified DVLA records. Updated as new MOTs are recorded.
Which year to buy? →

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

The 2018 Mercedes-Benz B-Class passes its MOT at 89.9%, well above the UK average of 80%, which is genuinely solid—but 23.4% of these vehicles have recorded a dangerous defect at some point, a red flag worth investigating on any used example you're considering. Petrol models perform better (91.3% pass rate) than their diesel counterparts (88.6%), so fuel type does matter for this generation.

These cars are running relatively low mileage for their age at a median of 32,567 miles, suggesting they've been treated as cherished family runabouts rather than workhorses. The average vehicle racks up 0.68 failures and 4.1 advisories per test, which points to minor wear rather than systematic problems—so get a pre-purchase inspection done and focus on brake and suspension components, which typically dominate that advisory count.

The 2018 Mercedes Benz B Class passes its MOT first time at roughly the UK average rate (89.9%) — solid but worth checking this vehicle's history carefully.

⚠️ Over 1 in 5 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

89.9%

UK average ~80%

Better than average

Dangerous (ever)

23.4%

At least once in MOT history

Check this vehicle

Avg failures / car

0.68

Over 5.8 tests on record

Moderate

Typical mileage

33k

Middle half: 24k–43k

For context

✅ Good baseline reliability. A 89.9% 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 4.1 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 3,875 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.

Average reliability — agree?

What tends to go wrong

Across 3,875 vehicles — figures show how many had each issue flagged at least once in their MOT history.

Tyre wear 34.3%

Offside Front Tyre worn close to legal limit/worn on edge · Nearside Front Tyre worn close to legal limit/worn on edge · Offside 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 23.4%

Front Brake pad(s) wearing thin · Rear Brake pad(s) wearing thin · Front Brake disc worn, pitted or scored, but not seriously weakened · …

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

Other issues 12.1%

Nearside Rear Child Seat fitted not allowing full inspection of adult belt · COVID-19 6 MONTH EXTENSION · Windscreen damaged but not adversely affecting driver's view · …

Data covers a 3-year window centred on 2018.

See this vehicle's full MOT history & AI hunches

Spot recurring advisories, hidden issues, and how it compares to 3,875 Mercedes Benz B Class cars.

Petrol vs Diesel

Pass rate difference of 2.7 percentage points — worth knowing if you're choosing between the two.

91.3%

Petrol

1,933 vehicles

88.6%

Diesel

1,940 vehicles

Before you buy a 2018 Mercedes Benz B Class

Based on MOT data from 3,875 vehicles — here's what to check.

📋 Check the full MOT history. 23.4% 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

Pass Rate by Fuel Type

Fuel type	Vehicles	Pass rate	Avg failures
Diesel (50%)	1,940	88.6%	0.78
Petrol (50%)	1,933	91.3%	0.57

Colour Breakdown

Based on 77,010 Mercedes Benz B Class vehicles registered in the UK — across all years. From DVLA registration records.

Black 24.5%

18,872

Silver 22.4%

17,281

Grey 19.2%

14,820

Blue 17%

13,065

White 9.9%

7,612

Red 4.9%

3,768

Gold 0.6%

441

Purple 0.5%

393

Brown 0.4%

285

Bronze 0.2%

182

Green 0.2%

149

Beige 0.2%

142

Mileage Distribution

Most 2018 Mercedes Benz B Class 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.

32,567

typical

23,660

low mileage

43,403

high mileage

Half of all 2018 Mercedes Benz B Class vehicles fall between 23,660 and 43,403 miles.

Is the mileage you're seeing normal?

✓ Under 23,660 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.

✓ 23,660–43,403 miles — normal for age. This is where most 2018 Mercedes Benz B Classs sit.

⚠ Over 58,594 miles — higher than typical. Not necessarily a problem, but check service history and look out for advisory build-up on tyres and brakes.

2018 Mercedes Benz B Class — Still on the Road

Almost all 2018 Mercedes Benz B Classs are still on the road.

Strong survival — 3,785 vehicles still getting MOTs in 2025, 99% of the peak.

Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2021–2025.

MOT History Averages

5.8

Avg MOT tests per vehicle

0.68

Avg failures per vehicle

4.1

Avg advisories per vehicle

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

2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2019

Or browse all models: Mercedes Benz →

Compare with another model

See how the 2018 Mercedes Benz B Class stacks up against a rival.

Average reliability — agree?