Mercedes 300

4,035 on UK roads in 2025-122 vs 2024

On the road

4,035

4,035 licensed

Change vs 2024

-2.9%

-122 cars

New in 2025

first-time registrations

Electrified

hybrid, plug-in & battery

The Mercedes 300 is an uncommon sight on UK roads, with 4,035 licensed in 2025 - down 2.9% on 2024. 16 were registered new in 2025. The fleet is overwhelmingly petrol (88%), with most in the Over 3.0L class. Most date from the Before 2000 era.

How many are left?

Licensed Mercedes 300 cars on the road over time

New registrations

First-time registrations per year

What the typical Mercedes 300 looks like

Fuel, engine size and age across every Mercedes 300 on the road today.

Fuel mix

Current split

4,035total

Petrol88.1%
Diesel11.7%
Hybrid0.0%
Other0.2%

Engine size

Cars on the road by engine capacity

Under 1.0L1
1.0-1.6L1
1.6-2.0L4
2.0-3.0L25
Over 3.0L4,004

How old are they?

Share of cars by the year they were first registered

Before 200098%
2000-20042%
2005-20090%
2020-20250%

MOT & reliability

2025 MOT data

How a Mercedes 300 holds up at its MOT and how it's driven - from 2,974 tests, tracked across 2022-2025.

First-time pass rate

Average for its class

81.7%

2,974 MOT tests in 2025 · 2,629 first-time

Pass rate over time

2022

81.2%

2023

79.7%

2024

80.8%

2025

81.7%

▲ 0.5 pts since 2022

Pass rate by age

First-time pass rate by the car's age (tested in 2025)

How a Mercedes 300 is driven

tracked across 2022-25

How much it's driven

miles a year, from 3,066 cars tracked across years

1,465miles a year · low use

94.5%

low · <5k

4.5%

avg · 5-15k

high · 15k+

Most cover 168-1,475 miles a year (median 525).

Miles driven by age

Yearly mileage as the car ages

Driven most when newer, easing as it gets older.

Mileage & condition

Typical mileage at test

Odometer when tested (2025)

112,511

44,488middle 50%: 70,549-146,690184,177

Typical odometer rising: 114,097 → 113,835 → 114,319 → 112,511

Holds up by mileage

Pass rate as the odometer climbs

Under 40k

88%

40-80k

87%

80-120k

80.7%

120k+

78.2%

Petrol vs diesel

First-time pass rate by fuel

Not enough data.

A 2025 Mercedes 300 passes first time 81.7% of the time - above the 77.6% UK average. The typical one is driven about 1,465 miles a year, and reliability is mostly about miles: 88% of low-mileage cars pass versus 78.2% past 120k.

Why a 300 fails its MOT

2025 MOT data

Of 480 first-time fails, here's what gets flagged most. Most cars fail on more than one item, so shares add up past 100%.

Where a 300 fails

Share of failed tests, by area

Lamps & electrical42.3%

Brakes37.1%

Suspension32.7%

Body & structure25.6%

Exhaust & emissions19%

Visibility18.5%

Steering10.8%

Tyres9%

Top specific defects

Exact items most often recorded as the reason a car failed

The aim of a headlamp is not within limits laid down in the requirements60

Windscreen washers not working or not providing sufficient fluid to clear the windscreen58

The strength or continuity of the load bearing structure within 30cm of any sub-frame, spring or suspension component mounting (a 'prescribed area') is significantly reduced or inadequately repaired49

Emissions levels exceed default limits44

A suspension joint dust cover missing or no longer prevents the ingress of dirt etc41

An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning40

A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning35

Exhaust system leaking or insecure32

Wiper blade missing or obviously not clearing the windscreen31

Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc29

21.3% flagged dangerous·3.2 defects per fail·480 fails analysed

Mercedes 300 - frequently asked

How many Mercedes 300 are left in the UK?

There are 4,035 Mercedes 300 cars still licensed on UK roads in 2025, down 2.9% on 2024.

How many new Mercedes 300 were registered in 2025?

16 brand-new Mercedes 300 cars were first registered in 2025.

What fuel does the typical Mercedes 300 use?

Most are petrol - about 88% of all Mercedes 300 on the road, with the majority in the Over 3.0L engine class. In total, 0% are electrified (hybrid, plug-in or battery).

How old is the typical Mercedes 300?

Most Mercedes 300 cars on the road today date from the Before 2000 era.

How reliable is the Mercedes 300?

81.7% of Mercedes 300 cars pass their MOT first time, compared with a UK average of 77.6% across all cars. The typical tested Mercedes 300 has around 104,731 miles on the clock.

Buying a Mercedes 300?

Before you buy a specific Mercedes 300, run its registration through AnalyzeMyCar for MOT history, mileage checks, service history and valuation.

Check a car

What the typical Mercedes 300 looks like

Fuel, engine size and age across every Mercedes 300 on the road today.

Fuel mix

Current split

4,035total

Petrol88.1%
Diesel11.7%
Hybrid0.0%
Other0.2%

Engine size

Cars on the road by engine capacity

Under 1.0L1
1.0-1.6L1
1.6-2.0L4
2.0-3.0L25
Over 3.0L4,004

How old are they?

Share of cars by the year they were first registered

Before 200098%
2000-20042%
2005-20090%
2020-20250%

MOT & reliability

2025 MOT data

How a Mercedes 300 holds up at its MOT and how it's driven - from 2,974 tests, tracked across 2022-2025.

First-time pass rate

Average for its class

81.7%

2,974 MOT tests in 2025 · 2,629 first-time

Pass rate over time

2022

81.2%

2023

79.7%

2024

80.8%

2025

81.7%

▲ 0.5 pts since 2022

Pass rate by age

First-time pass rate by the car's age (tested in 2025)

How a Mercedes 300 is driven

tracked across 2022-25

How much it's driven

miles a year, from 3,066 cars tracked across years

1,465miles a year · low use

94.5%

low · <5k

4.5%

avg · 5-15k

high · 15k+

Most cover 168-1,475 miles a year (median 525).

Miles driven by age

Yearly mileage as the car ages

Driven most when newer, easing as it gets older.

Mileage & condition

Typical mileage at test

Odometer when tested (2025)

112,511

44,488middle 50%: 70,549-146,690184,177

Typical odometer rising: 114,097 → 113,835 → 114,319 → 112,511

Holds up by mileage

Pass rate as the odometer climbs

Under 40k

88%

40-80k

87%

80-120k

80.7%

120k+

78.2%

Petrol vs diesel

First-time pass rate by fuel

Not enough data.

Why a 300 fails its MOT

2025 MOT data

Of 480 first-time fails, here's what gets flagged most. Most cars fail on more than one item, so shares add up past 100%.

Where a 300 fails

Share of failed tests, by area

Lamps & electrical42.3%

Brakes37.1%

Suspension32.7%

Body & structure25.6%

Exhaust & emissions19%

Visibility18.5%

Steering10.8%

Tyres9%

Top specific defects

Exact items most often recorded as the reason a car failed

The aim of a headlamp is not within limits laid down in the requirements60

Windscreen washers not working or not providing sufficient fluid to clear the windscreen58

Emissions levels exceed default limits44

A suspension joint dust cover missing or no longer prevents the ingress of dirt etc41

An obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning40

A lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning35

Exhaust system leaking or insecure32

Wiper blade missing or obviously not clearing the windscreen31

Steering rack gaiter or ball joint dust cover missing or no longer prevents the ingress of dirt etc29

21.3% flagged dangerous·3.2 defects per fail·480 fails analysed

Mercedes 300 - frequently asked

How many Mercedes 300 are left in the UK?

There are 4,035 Mercedes 300 cars still licensed on UK roads in 2025, down 2.9% on 2024.

How many new Mercedes 300 were registered in 2025?

16 brand-new Mercedes 300 cars were first registered in 2025.

What fuel does the typical Mercedes 300 use?

Most are petrol - about 88% of all Mercedes 300 on the road, with the majority in the Over 3.0L engine class. In total, 0% are electrified (hybrid, plug-in or battery).

How old is the typical Mercedes 300?

Most Mercedes 300 cars on the road today date from the Before 2000 era.

How reliable is the Mercedes 300?

81.7% of Mercedes 300 cars pass their MOT first time, compared with a UK average of 77.6% across all cars. The typical tested Mercedes 300 has around 104,731 miles on the clock.

Buying a Mercedes 300?

Before you buy a specific Mercedes 300, run its registration through AnalyzeMyCar for MOT history, mileage checks, service history and valuation.

Check a car