Every year DVSA publishes anonymised data from tens of millions of MOT tests. We've broken it down specifically for High Wycombe drivers — showing exactly what's failing, how often, and what you can do about it before test day.
Percentages indicate proportion of all MOT tests (not just failures) that recorded a defect in that category. A single test can record multiple defect categories.
1. Lights & Electrical Faults — 10.6% of All Tests
This is the most widespread defect category. A single blown bulb — headlight, brake light, indicator or number plate lamp — is an automatic MOT failure. Lighting faults are particularly prevalent in autumn and winter when cars are driven more in darkness and bulb failures are spotted later. Before your MOT in High Wycombe, walk around the car at night with someone else operating the lights, brakes and indicators. It takes five minutes and could save you a retest fee.
2. Brakes — 9.03% of All Tests
Brake efficiency is measured on a rolling road during the MOT. The test checks overall stopping power, balance between left and right wheels, and the handbrake. Uneven brake force — often caused by a seized caliper or worn pads on one side — causes imbalance failures even if the car stops quickly. High Wycombe's stop-start commuting routes on the A40 and through town put extra wear on front brake pads. We offer a free brake inspection before your MOT at Auto Clinics.
3. Tyres — 8.05% of All Tests
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre, around the full circumference. DVSA data shows tyres are the single most common individual failure item by volume — with millions of failures each year directly attributable to tread depth, sidewall damage or incorrect pressure. The easiest way to check at home is the 20p coin test: insert a 20p piece into the tread groove. If the outer band is visible, your tread may be below 1.6mm.
4. Suspension — 5.8% of All Tests
Worn shock absorbers, damaged coil springs, seized anti-roll bar drop links and corroded wishbone bushes all appear in suspension failures. A common sign is the car bouncing more than once after hitting a bump, or pulling to one side under braking. Buckinghamshire's rural roads — particularly routes out of High Wycombe towards the Chilterns — are harder on suspension components than motorway driving.
5. Emissions — 3.7% of All Tests
Diesel vehicles must pass a smoke opacity test; petrol cars are tested for CO and HC levels. A blocked DPF is the most common cause of diesel emissions failure. Auto Clinics offers on-site DPF cleaning and ECU diagnostics, meaning most emissions-related failures can be resolved and the retest completed the same day.
What This Means for High Wycombe Drivers
The South East consistently posts pass rates around 80%, which is above the UK average of 78.3%. But 1 in 5 vehicles in the region still fails. The good news: the three most common failure categories — lights, brakes and tyres — are all visible, checkable and fixable before test day. A pre-MOT inspection at Auto Clinics High Wycombe takes around 20 minutes and can identify issues before they become failures.