Audi A3 vs Mercedes-Benz A-Class: which is the better used buy?

On DVSA MOT records the Audi A3 is the more reliable used buy: it passes its first MOT 3.1 percentage points more often than the Mercedes-Benz A-Class once both are compared against what the national fleet scores at the same age. That comparison covers 82,085 real tests, not a survey.

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.

Model	Pass rate	Age-matched national	Difference	Tests
Audi A3	80.1%	76.4%	+3.7	43,706
Mercedes-Benz A-Class	81.8%	81.2%	+0.6	38,379

Source: DVSA MOT Anonymised Data 2025 (Open Government Licence v3.0). National first-time pass rate 77.3%. Applies to Great Britain — Northern Ireland is tested by the DVA under a separate manual.

Audi A3

8V (2013–2020) · Premium compact/family hatchback (also sold as Sportback, saloon and cabriolet) competing with the BMW 1 Series, Mercedes A-Class and VW Golf

The Audi A3 8V (2013–2020) is a solidly built, reasonably reliable premium family hatchback, but the single most important thing to check before buying is the condition of the S tronic dual-clutch automatic gearbox — specifically the 7-speed DQ200 dry-clutch unit fitted to 1.4 TFSI petrol and lower-power diesel models — since hesitant pull-away, low-speed shudder or a stored gearbox fault code point to expensive mechatronic or clutch pack wear. On 2.0 TDI diesel models, also insist on documented proof of cambelt (timing belt) replacement, since a snapped belt destroys the engine outright. For the best buy, target a well-documented 2019–2020 late-production car — built several years after Audi's 2016 mid-life facelift, once the wastegate rattle and EGR/DPF niggles seen on earlier cars had been progressively addressed through running production changes — and be most cautious with 2013–2014 first-of-generation examples, especially high-mileage S tronic models with a thin service history. Whichever engine and gearbox combination you choose, a full main-dealer or specialist service history covering DSG oil changes and the diesel cambelt is worth far more than a slightly lower mileage.

What goes wrong

S tronic (DSG) dry-clutch gearboxmajor
Hesitant or jerky pulling away from a stop, a shudder felt through the car at low speed, delayed gear engagement, an occasional flashing PRNDS display, and in worse cases a gearbox fault warning with the car defaulting to limp mode.
2013–2020, most reported on 1.4 TFSI petrol and lower-power diesel models fitted with the 7-speed DQ200 dry-clutch unit · Problems most commonly emerge from around 40,000–60,000 miles onward, especially where the recommended DSG oil and filter service (roughly every 40,000 miles/4 years) has been skipped · Roughly £800–£1,500 for a specialist mechatronic unit repair or reconditioning; a full replacement unit from a main dealer can run to £2,000 or more
Check: On the test drive, pull away from rest several times both cold and warm and feel for hesitation or shudder; check the service history for DSG oil/filter changes at roughly 40,000-mile intervals; ask a garage to scan for stored gearbox fault codes
2.0 TDI cambelt (timing belt)critical
No warning symptoms beforehand — if the belt snaps the pistons strike the valves and the engine is destroyed.
2013–2020 2.0 TDI diesel models · Manufacturer interval is up to around 100,000 miles or 5 years, though many independent specialists recommend renewing by 75,000 miles for peace of mind on a used example · Roughly £400–£900 for a routine belt, tensioner and water pump replacement at an independent specialist; a neglected belt that snaps typically means an engine rebuild or replacement costing several thousand pounds
Check: Get documented proof of cambelt replacement, including date and mileage, from the service history; if there is no evidence and the car is anywhere near the interval, budget for immediate replacement or negotiate the price down accordingly
1.4 TFSI wastegate actuator rattleminor
A metallic rattling noise from the engine bay, most noticeable on light throttle around 1,600–2,200rpm and worse from cold; can progress to reduced boost or limp mode if left unaddressed.
Most reported on pre-facelift 2013–2016 1.4 TFSI models, particularly the lower-power 122/125PS versions · Linked more to corrosion and wear of the actuator linkage than to a fixed mileage, but more commonly reported from around 40,000 miles onward · From around £50–£150 for an aftermarket actuator linkage fix, up to roughly £400–£900 for a full wastegate actuator or turbocharger replacement
Check: Listen for a rattle from the engine bay on a cold start and under light throttle in the 1,600–2,200rpm range
2.0 TDI EGR valve and coolermajor
Rough idle, hesitant throttle response, an illuminated engine management light, and in more serious cases the EGR cooler leaking coolant internally.
2.0 TDI diesel models across the 8V range, more common on cars used mainly for short urban journeys · Commonly reported from around 60,000–90,000 miles onward · Roughly £250–£500 for an EGR valve clean or replacement; around £500–£900 if the EGR cooler itself needs replacing
Check: Ask about any history of engine warning lights or limp mode; check coolant for contamination and ask whether the EGR system has recently been cleaned or replaced

Typical asking price:: 2013–2014 1.4 TFSI/1.6 TDI: £8,000–£11,500 | 2016–2018 facelift 1.0/1.5 TFSI: £11,500–£16,500 | 2019–2020 final-year Sportback/S line: £16,000–£21,500
Real-world economy:: 1.0 TFSI: 47–53 mpg. 1.4/1.5 TFSI: 42–48 mpg. 2.0 TDI: 52–60 mpg.
Vehicle tax:: £200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).
Best years:: 2019, 2020
Years to avoid:: 2013, 2014

Full A3 fault guide Used Audis

Mercedes-Benz A-Class

W177 (2018–present) · Premium compact hatchback competing with the Audi A3 and BMW 1 Series in the UK's small executive/family hatchback segment.

The Mercedes-Benz A-Class W177 (2018–present) is the third generation of Mercedes' premium hatchback, sold in the UK against the Audi A3 and BMW 1 Series. The single most important thing to check before buying any W177 is the 7G-DCT dual-clutch automatic gearbox — drive it from cold and feel for jerky, hesitant take-up or a thud when selecting Drive/Reverse, and insist on a full service history showing genuine MB 236.21-spec transmission fluid changes, since mechatronic and clutch-pack wear is the costliest fault on this car. Early launch-year cars (2018–2019) are the ones to treat most cautiously, as they carry the highest concentration of MBUX infotainment glitches and DCT teething issues that later software updates and running changes addressed. For the safest buy, target a 2023–2025 facelifted A-Class with full dealer or specialist service history and, if it's a diesel, evidence of regular longer runs rather than exclusively short urban trips, to minimise DPF and AdBlue-related risk. Even on a well-sorted car it's worth cycling the MBUX screens, listening for rough idle or turbo hesitation on the 1.3-litre petrol models, and testing the electric parking brake before handing over any money.

What goes wrong

7G-DCT dual-clutch automatic gearboxmajor
Jerky or hesitant take-up from a standstill, a noticeable clunk or thud when selecting Drive, Reverse or Neutral (worse when the car is cold), delayed engagement, and in more serious cases a warning message with the transmission dropping into limp mode.
Most commonly reported on 2018-2020 cars, though clutch-pack and mechatronic wear can appear on any W177 as mileage builds · Wear-related reports increase from roughly 50,000-70,000 miles, though software-related jerkiness can show up on much lower-mileage cars · £150-£300 for a software update/adaptation reset if it's a mapping issue; £1,000-£1,800 for a clutch pack at an independent specialist; £1,500-£2,500+ for a replacement mechatronic unit, more again at a main dealer
Check: Drive the car from cold and pull away repeatedly at low speed feeling for shudder or a delayed bite; select R and D back-to-back and listen for a loud clunk; ask for a full transmission service history showing genuine MB 236.21-spec fluid changes rather than a skipped 'lifetime fluid' claim.
MBUX infotainment and electrical systemsminor
Central and/or driver display freezing, going black, or rebooting on its own; Bluetooth dropping out; occasional loss of the reversing camera or parking sensor display; warning lights appearing without a genuine underlying fault.
Heavily concentrated on 2018-2019 launch cars; reports dropped off significantly from around 2020 as software and running changes were introduced · Can appear at any mileage since most cases are software-related rather than wear-related · Often free or low-cost as a dealer software/firmware update; £300-£500 to replace a faulty display data cable; £600-£1,200+ for a replacement head unit or screen module if the hardware itself has failed
Check: Cycle through every infotainment menu, pair a phone via Bluetooth, and confirm the reversing camera and parking sensor display work correctly; ask whether the car has had any MBUX-related software updates applied by a dealer.
Diesel particulate filter (DPF) blockingmajor
DPF or exhaust system warning light, reduced power or a 'see owner's manual' message, and a noticeable smell or extra exhaust smoke during a forced regeneration; most common on cars used mainly for short, low-speed urban journeys.
Applies across A180d/A200d diesel models throughout the W177 range, 2018-2025 · Not strictly mileage-linked — on a car used mostly for short trips it can appear well under 30,000 miles, while a diesel with regular motorway miles may never show it · Free if caught early by driving for 15-20 minutes at sustained motorway speed to complete a regeneration; £100-£250 for a professional forced regen or clean; £1,000-£1,800 for a replacement DPF if the warning has been ignored for a long period
Check: Ask how the car is normally driven (short urban trips versus regular longer runs), check the service history for any DPF-related warnings or replacements, and take it for a test drive long enough to see a regeneration cycle behave normally.
AdBlue/SCR (diesel exhaust fluid) systemmajor
'AdBlue system fault, see owner's manual' warning, dosing pump or tank heater faults, and — if left unresolved — a countdown to the engine refusing to restart once AdBlue is exhausted or the system logs a fault.
Diesel (A180d/A200d) models across the range, most commonly reported on 2019-2022 cars · Typically reported from around 40,000-60,000 miles, or on cars that have sat unused for long periods between drives · £20-£40 to simply top up the AdBlue tank; £300-£600 for a sensor or tank heater element; £600-£1,000+ for a dosing pump or injector replacement
Check: Check the dashboard for any current or recently-cleared AdBlue warnings, confirm AdBlue top-ups appear on the service record, and ask the seller directly whether the warning has ever shown.

Typical asking price:: 2018–2019 A180/A200 Sport: £13,500–£18,500 | 2020–2021 AMG Line: £17,500–£24,000 | 2022–2023 facelift/A250e PHEV: £22,000–£30,000
Real-world economy:: A180d diesel: 55–62 mpg. A180/A200 petrol: 40–46 mpg. A250e PHEV: 20–28 miles electric range, 35–45 mpg once depleted.
Vehicle tax:: £200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).
Best years:: 2023, 2024, 2025
Years to avoid:: 2018, 2019

Full A-Class fault guide Used Mercedes-Benzs

Which one suits you

Audi A3

Good for: Buyers wanting Golf-level engineering with a more premium interior and stronger resale values. A 2016+ facelift car with the revised infotainment and confirmed timing-chain history is the safer buy.

Less good for: Anyone considering a pre-2016 1.4 TFSI or 2.0 TDI without documented timing-chain/tensioner history — this is the single most expensive fault on the car if it lets go.

Mercedes-Benz A-Class

Good for: Buyers wanting the most premium-feeling interior in this class, especially the MBUX infotainment. A 2021+ car with confirmed DCT service history is the safer buy for the automatic.

Less good for: Anyone considering the 7G-DCT automatic without documented gearbox oil/filter change history — this is the highest-risk combination on the car. Buyers wanting maximum rear legroom, which is tight for the class.

Frequently Asked Questions

Which is more reliable, the Audi A3 or the Mercedes-Benz A-Class?

The Audi A3. It passes its first MOT 3.1 percentage points more often than the Mercedes-Benz A-Class once both are age-adjusted, across 82,085 DVSA-recorded tests.

What is the MOT pass rate for the Audi A3?

80.1% of Audi A3s pass their MOT first time, from 43,706 tests in DVSA's records. The national first-time rate is 77.3%, but cars of this model's age average 76.4% — so it runs 3.7 points better than its age group.

What is the MOT pass rate for the Mercedes-Benz A-Class?

81.8% of Mercedes-Benz A-Classs pass their MOT first time, from 38,379 tests. Against the 81.2% that cars of its age average, it runs 0.6 points better.

Which years should I avoid?

For the Audi A3, The earliest 2013–2014 cars carry the most forum and press reports of the 1.4 TFSI wastegate actuator rattle and diesel EGR/DPF glitches that Audi progressively addressed through later production changes, and as the oldest cars in the generation they have had the longest time to accumulate DSG mechatronic and clutch wear wherever the 40,000-mile service interval was skipped. For the Mercedes-Benz A-Class, 2018 and 2019 were the UK launch years for the W177 and carry the highest concentration of MBUX infotainment glitches (screen freezes, reboots) and 7G-DCT low-speed jerkiness reported by owners and the motoring press, before Mercedes rolled out software fixes and running changes.

Which is cheaper to run?

The Audi A3 returns 1.0 TFSI: 47–53 mpg. 1.4/1.5 TFSI: 42–48 mpg. 2.0 TDI: 52–60 mpg. in real UK driving; the Mercedes-Benz A-Class returns A180d diesel: 55–62 mpg. A180/A200 petrol: 40–46 mpg. A250e PHEV: 20–28 miles electric range, 35–45 mpg once depleted.. Vehicle tax: A3 — £200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. Cars registered 2001–2017 pay a CO2 band, roughly £20–£790/year (2026/27 rates).; A-Class — £200/year standard rate from the second year, hybrids included — the alternative-fuel discount ended on 1 April 2025. Cars registered 2001–2017 pay a CO2 band, 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: 2026-08-30 / 2026-08-30.