Performance by cohort

3 year bands · 79,501 tests

Pass rate climbs 2.3 points across the cohorts — newer 320 examples clear the test more reliably than the early cars.

Pre-2018 cohort 41,773

Pass

87.5%

Fail

9.8%

PRS

2.3%

Avg mileage at test

72,974 mi

2018–2020 cohort 35,127

Pass

89.8%

Fail

8.2%

PRS

1.6%

Avg mileage at test

45,770 mi

2021+ cohort 2,601

Pass

89.8%

Fail

7.8%

PRS

1.8%

Avg mileage at test

29,264 mi

Cohort = vehicle's first-registration year band. Same model, different generations of build.

Generations on file · 2

BMW 320 · UK market

Photos: Wikimedia Commons · CC BY-SA / CC BY / public domain.

The picture

BMW 320 at 87.5%: above average 3 Series with lighting and tyre items as the main trip-wires

The BMW 320 posts 87.5% first-time pass from 43,304 tests — well above the UK fleet average at an average presenting mileage of 76,432. Top failures are tyre tread, rear plate lamp faults and windscreen chips. The 320's rear plate lamp failure rate is consistent with the G20 generation's LED tail cluster, where individual elements fail silently. The wide performance tyres on M Sport trim variants wear faster than the efficient driving style the 2.0-litre diesel rewards. Shock absorber leaks appear in the top ten for the F30-generation cars. At 87.5% and well above average, the 320 is a strong performer. Pre-test: verify lamp function and tyre depths.

ABI Insurance Group

Group 28–40

Above average — worth comparing quotes before buying. Lower groups cost less to insure; UK fleet average is around Group 22.

Source: ABI Group Rating Panel · administered by Thatcham Research · groups cover standard variants; performance trims may sit higher. Browse all insurance groups →

28–40

out of 50

Compare quotes →

Top ten reasons for rejection.

Filter failures:

Hide wear items to see the model's real defects.

01

Tyre tread depth not in accordance with the requirements

1,449 occurrences · 1.8% of tests
02

Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view

1,240 occurrences · 1.6% of tests
03

A tyre seriously damaged

1,041 occurrences · 1.3% of tests
04

a brake lining or pad worn below 1.5mm

807 occurrences · 1.0% of tests
05

A tyre cords visible or damaged

648 occurrences · 0.8% of tests
06

A tyre seriously damaged

569 occurrences · 0.7% of tests
07

A shock absorber damaged to the extent that it does not function or showing signs of severe leakage

457 occurrences · 0.6% of tests
08

Wiper blade defective

345 occurrences · 0.4% of tests
09

Windscreen washers not working or not providing sufficient fluid to clear the windscreen

321 occurrences · 0.4% of tests
10

Steering rack gaiter or ball joint dust cover damaged or deteriorated

254 occurrences · 0.3% of tests

Counts cover Major and Dangerous defects logged at test. Advisory items excluded so this shows why a car was rejected, not just what the tester flagged in passing.

Worst-case fix budget · top 3 failures

£200–£350

If every one of this 320's most-logged Major fails hit at the same MOT, that's the real-world UK garage range. Reality is usually one or two items, not all of them. Open the estimator →

Try the calculator

Build your own retest budget.

Year-band analysis

Best year to buy. Worst to avoid.

First-time MOT pass rate split by registration band. A 2.3-point gap between bands is modest — the year you buy BMW 320 makes a small but real difference to MOT outcomes.

Best band to buy

89.8%

2021+ registration

the 2021-on band climbs to 89.8% — a 2.3-point improvement. Tests in this band average 29,264 miles — roughly 44K miles fewer on the clock than the older band. Failures here are mostly wear items: has a cut in excess of the…, has a bulge, caused by separation or… — the structural issues that drag down older examples don't appear in the top-10 for this band. Post-2020 examples are early in their MOT life and generally show the cleanest records.

Band to be cautious about

87.5%

Pre-2018 registration

On the older band (pre-2018), the data shows a 87.5% pass rate against a fleet average of 89.8% on the newer band. The main culprits logged at test: tread depth below requirements of 1.6mm, damaged but not adversely affecting driver's view, and has a cut in excess of the…. Average mileage on test for this band is 72,974 miles — high-mileage wear items are a recurring theme.

Best band to buy: 2021+ (89.8% first-time pass). Worst band to avoid: pre-2018 (87.5% pass). That's a 2.3-point spread across 41,773 older tests and 2,601 newer ones — year of build makes a material difference on this model.

Year-spread leaderboard →

Tools that pre-empt a retest.

Picked against this car's top failure patterns. Affiliate links to Amazon UK — we earn a small cut at no cost to you. Disclosed up-front, doesn't shape the data.

Item 01 · Amazon UK

Digital tyre-tread depth gauge

Five quid for a gauge beats £150 for a retest. UK MOT minimum is 1.6mm — most testers fail anything below 2mm to be safe.

Search Amazon UK

Item 02 · Amazon UK

Brake pad measurement gauge

Testers fail pads under 1.5mm. A wear gauge tells you if you've got two months left or two weeks.

Search Amazon UK

My Motor World · affiliate

Parts & supplies for this fix

Affiliate links — small commission, no extra cost to you.

Summit

Summit ADRG-640 BMW Replacement Stick-On Tinted Mirror Glass LHS

£10.99

View at My Motor World →

Summit

Summit ADRG-904 BMW Replacement Stick-On Tinted Mirror Glass RHS

£10.99

View at My Motor World →

Summit

Summit ADRG-905 BMW Replacement Stick-On Tinted Mirror Glass LHS

£10.99

View at My Motor World →

Draper Expert

Draper Expert Oil Filter Socket for Audi, BMW, Mercedes-Benz, Porsche and VW

£18.69

View at My Motor World →

Click Mechanic · affiliate

Book a mobile mechanic

Affiliate links — small commission, no extra cost to you.

Mobile mechanic · UK-wide

Book a mechanic at your door.

Fixed-price quotes upfront. No garage needed. Click Mechanic sends a vetted local mechanic to you — home, work, or roadside.

Get a quote →

Owner reports · Honest John

What owners actually report.

Verbatim faults logged by owners on honestjohn.co.uk over recent years. We didn't summarise — these are the words people typed in.

What's good

The BMW 320 is the volume engine in the 3 Series range, available in petrol (320i) and diesel (320d) configurations across F30 and G20 generations. Excellent driving dynamics, good fuel economy on the 320d, wide model range.

Buying or keeping a 320?

Use the failure ranking as a pre-test checklist or a haggling lever. Treat the headline pass rate as a fleet-wide trend, not a guarantee on any individual car.

If you own a 320 and your last MOT looked nothing like the ranked failures above, that's normal — individual cars vary widely. The ranking shows the patterns testers flag most often across the country.