73 AUTO

MOT performance

Hyundai i30 vs Mercedes-Benz CLA: MOT pass rates compared

In 2023–2024, 65.3% of 211,998 Hyundai i30 MOT tests and 80.8% of 117,936 Mercedes-Benz CLA tests passed first time — 15.4 points in favour of the Mercedes-Benz CLA. Once age, mileage and fuel are allowed for, the Mercedes-Benz CLA fails less often than the Hyundai i30: 0.94× against 1.16× the national rate for comparable cars.

211,998 Hyundai i30 and 117,936 Mercedes-Benz CLA MOT tests, 2023–2024

Check a specific car's MOT history and running costs

At a glance

Hyundai i30 vs Mercedes-Benz CLA MOT results
FigureValueBasis
Hyundai i30: first-time pass rate65.3%±0.2 pts (95%), n = 211,998
Mercedes-Benz CLA: first-time pass rate80.8%±0.2 pts (95%), n = 117,936
Hyundai i30: failures vs similar cars+16%same age, mileage and fuel = 1.00
Mercedes-Benz CLA: failures vs similar cars-6%same age, mileage and fuel = 1.00
Hyundai i30: dangerous defect10.2%n = 211,998
Mercedes-Benz CLA: dangerous defect8.4%n = 117,936
Average age at test9.3 vs 5.5 yearsHyundai i30 vs Mercedes-Benz CLA

Why the raw pass rates can mislead

The Hyundai i30 was tested at an older average age (9.3 years against 5.5), and older cars fail more often whatever they are. That is why the table above also shows failures against cars of the same age, mileage and fuel: it compares the models, not their fleets.

Failure areas side by side

Share of MOT tests that failed on each area, and in brackets how that compares with cars of the same age, mileage and fuel (1.00 = national average). The clearest difference is steering, where the Hyundai i30 fails 21.0 times as often on an adjusted basis.

Hyundai i30 vs Mercedes-Benz CLA MOT failures by area
AreaHyundai i30Mercedes-Benz CLA
Brakes12.3% (+82%)3.1% (-26%)
Steering5.8% (+192%)0.1% (-86%)
Suspension8.8% (-8%)2.9% (-28%)
Tyres7.3% (+7%)9.1% (+47%)
Road wheels0.3% (-20%)0.8% (+192%)
Lights, reflectors and electrical14.9% (+29%)3.1% (-47%)
Body, chassis and structure1.9% (-41%)0.4% (-69%)
Driver's view of the road5.2% (+12%)3.0% (-16%)
Noise, emissions and leaks1.6% (-47%)1.8% (+13%)
Seat belts and airbags0.4% (-54%)1.1% (+134%)
Registration plates and VIN0.3% (-10%)0.5% (+107%)
Speedometer and driving controls0.0% (-16%)0.0% (Same)

Pass rate at the same age

Comparing cars of the same age removes most of the fleet-age effect from the raw rates.

Hyundai i30 vs Mercedes-Benz CLA MOT pass rate by age at test
Age at testHyundai i30Mercedes-Benz CLA
3-4 years87.1% (n = 14,769)84.9% (n = 30,741)
5-6 years81.9% (n = 27,785)81.0% (n = 32,177)
7-8 years70.8% (n = 44,408)77.4% (n = 28,285)
9-10 years61.1% (n = 40,369)73.4% (n = 13,080)
11-12 years55.8% (n = 36,844)74.0% (n = 738)

Most common failure item

  • Hyundai i30 · stop lamp: not working (4.85% of tests)
  • Mercedes-Benz CLA · tread depth: tread depth below requirements of 1.6mm (2.50% of tests)

MOT results reflect how cars are maintained as well as how they are built, so a gap between two models is a difference in test performance, not proof that one is more reliable. For one car, its own MOT history says more than any average.

Check a specific car

Enter a UK registration to see that car's own MOT history and what it is likely to cost to own. Your first check is free and shows the vehicle summary and its headline ownership cost. The category-by-category breakdown is part of a paid check.

UK number plate or 17-character VIN

About this data. These are MOT test results, not a measure of mechanical reliability: a car's MOT outcome reflects its condition on the day, which depends on how it has been maintained and driven as well as how it was built. Figures cover class 4 vehicles (cars and light vans), normal tests only (retests excluded), outcomes pass, fail and pass after rectification at the station; vehicles at least 2.5 years old at test. Tests from 2023-01-01 to 2024-12-30. “Compared with similar cars” means compared with the national rate for cars of the same age, mileage band and fuel. Contains public sector information licensed under the Open Government Licence v3.0. Makes and models are matched to 73 Auto's vehicle catalogue; tests that can't be matched are left out rather than guessed. See how the MOT figures are produced.