Know Your MOT
28.1%fail rate

Btm 50 common MOT failures and failure rate

What a Btm 50 fails its MOT on, from real DVSA test data, and the part that resolves each item.

Based on 64 MOT tests in DVSA data.

About 28.1% of MOT tests recorded on the Btm 50 in DVSA data end in a failure. The same handful of items account for most of them.

Its most common failure is brakes, which makes up 61.1% of the Btm 50's failures, followed by brakes, lamps & electrical, tyres, steering. Each item below links to the part that resolves it. Confirm the exact fitment against your registration or VIN before buying, and have safety-critical work done by a competent mechanic.

What it fails on, and why

Brakes61.1% of failures

Brake failures cover worn pads and discs, an imbalance between wheels, corroded or scored discs, or a binding caliper. Braking efficiency is measured on a rolling road, so a spongy or pulling brake shows up as a low reading.

Lamps & electrical44.4% of failures

Lighting is the single most common MOT failure and the cheapest to put right. A blown headlight, brake-light or number-plate bulb, a cracked lens, or a headlamp beam that points too high or low will all fail. Most are a two-minute bulb swap.

Tyres33.3% of failures

Tyres fail for tread below the 1.6mm legal limit across the central three-quarters, uneven or exposed-cord wear, or sidewall damage. The tester inspects all four; a single illegal tyre is a fail.

Steering22.2% of failures

Steering faults are typically worn track-rod ends or ball joints, play in the rack, or a split gaiter letting grease out and dirt in. Excessive free play at the wheel fails.

Registration plate11.1% of failures

A missing, damaged, dirty or incorrectly-spaced number plate, or one using the wrong font, will fail. A replacement plate is inexpensive.

Other11.1% of failures

This covers a range of smaller items, from a non-working horn to a warning light left on.

The parts that fix each

If your car has just failed, you have 10 working days to fix the items and get a free partial retest. These are the usual parts; confirm the exact fitment against your registration or VIN before buying.

For the brakes failure: Btm 50 brake pads and discsSearch Amazon for Btm 50 brake pads and discsaffiliate searchFind Btm 50 brake pads and discs on eBayaffiliate
For the lamps & electrical failure: Btm 50 headlight and indicator bulbsSearch Amazon for Btm 50 headlight and indicator bulbsaffiliate searchFind Btm 50 headlight and indicator bulbs on eBayaffiliate
For the tyres failure: Btm 50 tyresSearch Amazon for Btm 50 tyresaffiliate searchFind Btm 50 tyres on eBayaffiliate
For the steering failure: Btm 50 steering track rod endsSearch Amazon for Btm 50 steering track rod endsaffiliate searchFind Btm 50 steering track rod ends on eBayaffiliate
For the registration plate failure: Btm 50 number plateSearch Amazon for Btm 50 number plateaffiliate searchFind Btm 50 number plate on eBayaffiliate

Other models

Btm Bt125t-12 MOT failures25.6% failure rateBtm Bt49qt-9 MOT failures27.0% failure rateBtm Unknown MOT failures25.5% failure rateFord Fiesta MOT failures27.1% failure rate

Sources: DVSA MOT History API: MOT test results and defect data ยท DVSA MOT testing data for Great Britain