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BMW 3 Series vs Mercedes-Benz C-Class: which is the better used buy?

On DVSA MOT records the BMW 3 Series does better at its MOT: measured against cars of the same age, it comes out 2.3 percentage points ahead of the Mercedes-Benz C-Class on first-time MOT passes. That comparison covers 86,042 real tests across every generation on the road, not a survey. A pass with rectification at the station counts as a pass here, and as a failure in DVSA's own initial-test measure. The MOT checks safety and emissions items, not the engine, clutch or gearbox, so this is one measure of how each car holds up rather than a full reliability verdict; the common faults below cover the rest.

MOT first-time pass rate

Counted from DVSA’s anonymised MOT test records. “vs age-matched” compares each model against what the national fleet scores at the same age — the only fair better-or-worse number, because an older fleet fails more whatever its build quality.

BMW 3 Series
Pass rate79.9%
Age-matched national75.1%
Difference+4.9
Tests48,624
Mercedes-Benz C-Class
Pass rate78.6%
Age-matched national76.0%
Difference+2.6
Tests37,418

These figures count every generation still on the road, not only the one described below: mostly BMW 3 Series registered 1999–2022 and Mercedes-Benz C-Class registered 2002–2022.

Source: DVSA MOT Anonymised Data 2025 (Open Government Licence v3.0). National first-time pass rate 77.3%. Class 4 tests in Great Britain, test type NT (a normal annual test), retests excluded. A pass, or a pass with rectification at the station, counts as a first-time pass; DVSA's own initial-test measure counts a rectified pass as a failure and so reports a lower figure. Testing in Northern Ireland is run separately by the DVA under its own rules. The difference is worked out before rounding, so it can be 0.1 away from the two rounded figures beside it.

BMW 3 Series

F30 (2012–2019) / G20 (2019–present) · D-segment executive saloon and touring estate. The most popular used premium car in the UK by volume. Available in a wide range of engines: 316i, 318i, 320i, 330i petrols; 316d, 318d, 320d, 330d diesels; 330e plug-in hybrid. Saloon, Touring (estate), and Gran Turismo body styles.

The BMW 3 Series (F30 2012–2019, G20 2019-on) rewards disciplined maintenance. On the pre-2015 N47 diesel, owners report the rear-mounted timing chain failing, an engine-out repair, so ask for chain history. The B47 diesel and B48 petrol that followed from 2015 are much better regarded. Full BMW-dealer or specialist service history is essential.

What goes wrong

  • Safety recall R/2022/255recall
    Undetected EGR System leaks may cause thermal activity in the intake manifold
    322,745 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 3 December 2014 and 12 July 2021
    Large recall — 322,745 vehicles. Check a car by registration on GOV.UK.
  • Safety recall R/2022/206recall
    The exhaust gas recirculation cooler may leak over time and cause thermal incident
    319,399 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 9 December 2011 and 4 June 2019
    Large recall — 319,399 vehicles. Check a car by registration on GOV.UK.
  • N47 diesel timing chain failure (F30 2012–2015)critical
    Chain rattle on cold start; rattling from rear of engine; engine management light; in severe cases, sudden engine failure
    F30 2012–2015 with N47 diesel (316d, 318d, 320d) · From 60,000 miles; can occur earlier if oil changes were delayed · £3,000–£6,000 timing chain replacement (rear-mounted chain requires engine removal); up to £10,000+ if the chain has jumped and damaged the engine
    Check: This is the single most critical check on any F30 N47 diesel. The N47 chain is rear-mounted — listen for chain rattle at idle with the bonnet up. Ask for proof of timing chain replacement in the service history. If the chain has not been replaced and the car has over 75,000 miles, budget for the repair or walk away. The B47 diesel (post-2015 on the F30 facelift and all G20) is unaffected.
  • Electric water pump failure (N20/B46/B48 petrols)major
    Coolant warning light; engine overheating; steam from engine bay; loss of heat from heater
    F30 2012–2019 petrol models (N20 engine) · From 50,000 miles; often fails between 60,000–95,000 miles · £600–£1,200 water pump replacement
    Check: Check coolant level and condition. Ask about any history of overheating or coolant warning lights. The electric water pump on N20 engines is a known maintenance item — not catastrophic if caught early, but a failed pump can cause overheating if ignored. Budget for proactive replacement on high-mileage N20 cars.
Typical asking price:
£5,295–£19,999, median £10,995 (middle 80% and median, cars on Autoza on 29 October 2026)
Fuel economy:
47–57 mpg (320d real-world UK mixed motorway); 35–44 mpg (320i petrol real-world)
Vehicle tax:
£200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. A car registered from April 2017 with a list price over £40,000 when new adds the £440/year Expensive Car Supplement in years 2–6 (£640 in all). Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).
Best years:
2019, 2020
Years to avoid:
2012
Used BMW 3 Series for saleFull 3 Series fault guideUsed BMWs

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Mercedes-Benz C-Class

W205 (2014–2021) / W206 (2021–present) · D-segment executive saloon, estate (T-Model), and coupe (C205). Direct competitor to BMW 3 Series and Audi A4. Available with petrol (C180, C200, C300), diesel (C200d, C220d, C300d), and PHEV (C300e/de) engines. One of the most popular used premium cars in the UK.

The Mercedes C-Class W205 is a beautifully built executive car. Owners most often report electrical faults, AIRMATIC air-suspension problems and oil leaks, plus timing-chain issues on pre-2016 M274 petrols and oil leaks on early OM651 diesels. A good independent Mercedes specialist keeps running costs manageable. Target the mid-2018 facelift or later.

What goes wrong

  • Safety recall R/2021/134recall
    The behaviour of the emergency call system might not meet specifications
    162,581 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 4 January 2016 and 29 January 2021
    Large recall — 162,581 vehicles. Check a car by registration on GOV.UK.
  • Safety recall R/2021/110recall
    The behaviour of the emergency call system might not meet specifications
    108,971 vehicles in the whole recall (DVSA’s figure for every model it covers) · built between 4 January 2016 and 29 January 2021
    Large recall — 108,971 vehicles. Check a car by registration on GOV.UK.
  • M274 engine timing chain (C200/C250 petrol, pre-2016)critical
    Rattling on cold start from the rear of the engine; timing-related engine management codes; rough running
    W205 2014–2016 with M274 engine (C180, C200, C250) · From 50,000 miles; higher risk above 60,000 miles · £1,500–£3,500 timing chain replacement; more if engine damage has occurred
    Check: Listen for chain rattle on cold start. Check the service history for evidence of the M274 updated timing chain tensioner being applied. Post-2016 W205 models use the updated M274 specification — significantly lower risk.
  • AIRMATIC suspension failure (C-Class with AIRMATIC option)major
    "Car too low" warning; suspension compressor noise; car sits unevenly; ride height varies after standing overnight
    2014–2021 (W205 with AIRMATIC air suspension option) · From 50,000 miles; risk increases with age (rubber bladders degrade) · £600–£1,200 per air strut; £400–£800 compressor; £200–£400 ride height sensors
    Check: Check whether the car has AIRMATIC air suspension or conventional coil springs (AMG Line and higher trims are more commonly AIRMATIC). If AIRMATIC: walk around the car on level ground and check it sits evenly. Listen for compressor noise on startup. AIRMATIC repairs are one of the highest-cost common fault areas on used W205s. Cars with conventional springs avoid this entirely.
Typical asking price:
£7,895–£19,990, median £12,495 (middle 80% and median, cars on Autoza on 29 October 2026)
Fuel economy:
49–57 mpg (C220d real-world UK motorway); 38–44 mpg (C200 petrol real-world)
Vehicle tax:
£200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. A car registered from April 2017 with a list price over £40,000 when new adds the £440/year Expensive Car Supplement in years 2–6 (£640 in all). Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).
Best years:
2019, 2021
Used Mercedes-Benz C-Class for saleFull C-Class fault guideUsed Mercedes-Benzes

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Which one suits you

BMW 3 Series

Good for: Buyers who want a genuine driver's car and are prepared to maintain it properly. Motorway-mile buyers who will use the 320d's diesel efficiency on long UK commutes. Buyers with a BMW specialist garage lined up for servicing.

Less good for: Buyers who want the lowest total cost of ownership — a Toyota Corolla or Skoda Octavia will cost meaningfully less to run. F30 N47 diesel buyers without verified timing chain history — this is a potentially catastrophic repair. First-time BMW buyers who plan to service it at the cheapest possible garage — BMW models require BMW-specific knowledge and fluids.

Mercedes-Benz C-Class

Good for: Buyers who want Mercedes-Benz prestige and build quality and will use a specialist for servicing. W205 facelift (mid-2018 on) buyers with documented service history. C300e PHEV buyers with home charging who want a premium PHEV at this price point.

Less good for: Buyers looking for the lowest total cost of ownership in the executive segment — main-dealer servicing is expensive. W205 2014–2016 buyers without verified timing chain history on M274 engines. Cars with AIRMATIC suspension without recent AIRMATIC service history.

Frequently Asked Questions

Which is more reliable, the BMW 3 Series or the Mercedes-Benz C-Class?
On the MOT measure, the BMW 3 Series: measured against cars of the same age, it comes out 2.3 percentage points ahead of the Mercedes-Benz C-Class on first-time MOT passes, across 86,042 DVSA-recorded tests covering every generation on the road. A pass with rectification at the station counts as a pass here, and as a failure in DVSA's own initial-test measure. The MOT checks safety and emissions items, not the engine, clutch or gearbox, so this is one measure of how each car holds up rather than a full reliability verdict.
How do the MOT pass rates of the BMW 3 Series and the Mercedes-Benz C-Class compare?
79.9% of BMW 3 Series pass their MOT first time (48,624 tests in DVSA's records) and 78.6% of Mercedes-Benz C-Class pass their MOT first time (37,418 tests). The national first-time rate is 77.3%, but cars of the BMW 3 Series's age average 75.1% and cars of the Mercedes-Benz C-Class's age 76.0% — so the BMW 3 Series runs 4.9 points better than its age group and the Mercedes-Benz C-Class runs 2.6 points better than its own. A pass with rectification at the station counts as a pass here, and as a failure in DVSA's own initial-test measure.
Which years of the BMW 3 Series and Mercedes-Benz C-Class should I avoid?
BMW 3 Series: 2012–2014 F30 with N47 diesel: the N47 2.0-litre diesel used in 316d, 318d, and 320d had a rear-mounted timing chain that stretched and failed prematurely, often at 60,000–95,000 miles. The repair requires removing the engine — costs of £3,000–£6,000 were common. Many N47 engines were replaced under extended warranty or goodwill; survivors without documented chain replacement are high-risk. The DVSA MOT table on this page rates 2013 and 2014 registrations above all cars registered those years, so they are not named as years to avoid. Mercedes-Benz C-Class: 2014–2016 launch cars: the most owner reports of M274 timing chain issues, gearbox 7G-Tronic valve body problems, panoramic roof seal leaks and electrical faults. The OM651 diesel used in early C220 CDI also had documented oil leaks from the turbo feed pipe. The DVSA MOT table on this page rates 2014, 2015 and 2016 registrations above all cars registered those years, so they are not named as years to avoid. Judge a C-Class by its registration, service history and the checks below rather than by year.
Is the BMW 3 Series or the Mercedes-Benz C-Class cheaper to run?
On fuel the two are too close to call: the most economical versions return up to 57 mpg (BMW 3 Series) and 57 mpg (Mercedes-Benz C-Class), on the figures in our model guides. For cars registered from April 2017, vehicle tax works the same way for both: the £200/year standard rate from the second year, hybrids included, plus the £440/year Expensive Car Supplement in years 2–6 on a car that listed at over £40,000 new — the price when new, not what you pay for it used. Any BMW 3 Series or Mercedes-Benz C-Class registered between 1 March 2001 and 31 March 2017 pays a CO2 band instead, roughly £20–£790/year (2026/27 rates). Insurance differs mainly by driver and postcode rather than by model, so treat any model-level insurance figure with caution.

MOT figures are counted from DVSA records and are the only measured statistic here. Prices, economy and tax bands are indicative and vary by specification, condition and where the car has lived. Last reviewed: 2026-10-06 / 2026-10-06.