Photo: Alexander Migl, CC BY-SA 4.0
Mercedes Benz
1,616 MOT tests analysed. sits above the UK fleet average — here's where Gla 220 Amg Line Prem + D 4M As pass, fail, and end up on the retest sheet.
That's 16.4 points above the UK fleet average across our 1,984 tracked models — a confident result.
Pass
93.9%
Pass-after-fix
1.5%
Fail
4.5%
Avg miles
25,562
Pass + Pass-after-fix + Fail = 100%
Diesel cars registered from September 2015 generally meet Euro 6 — compliant in London ULEZ, Birmingham CAZ, Bristol CAZ, and Glasgow LEZ.
Performance by cohort
2 year bands · 1,616 tests
Pass rate climbs 2.3 points across the cohorts — newer Gla 220 Amg Line Prem + D 4M A examples clear the test more reliably than the early cars.
Pass
92.4%
Fail
4.7%
PRS
2.4%
Avg mileage at test
30,230 mi
Pass
94.7%
Fail
4.3%
PRS
1.0%
Avg mileage at test
22,962 mi
Cohort = vehicle's first-registration year band. Same model, different generations of build.
The picture
Across 1,616 MOT tests, the Gla 220 Amg Line Prem + D 4m A returns 93.9% first-time pass — comfortably ahead of the UK fleet average. The single most-logged Major fail is a seriously damaged tyre. A defective wiper blade and windscreen damage round out the top three. Average tested mileage sits at 25,562, which is the lens to read those failure rankings through. If you own one and the next test is close, the ranked list below is a sensible pre-test checklist.
Filter failures:
Hide categories
Tick a category to hide it from rankings sitewide. Saved in this browser only.
A tyre seriously damaged
35 occurrences · 2.2% of tests
Wiper blade defective
17 occurrences · 1.1% of tests
Windscreen or window damaged or seriously discoloured but not adversely affecting driver's view
14 occurrences · 0.9% of tests
Tyre tread depth not in accordance with the requirements
6 occurrences · 0.4% of tests
Brake lining or pad worn down to wear indicator
6 occurrences · 0.4% of tests
A tyre cords visible or damaged
4 occurrences · 0.2% of tests
A tyre cords visible or damaged
3 occurrences · 0.2% of tests
Parking brake efficiency below minimum requirement
3 occurrences · 0.2% of tests
Engine MIL illuminated indicating a malfunction
2 occurrences · 0.1% of tests
a brake lining or pad worn below 1.5mm
2 occurrences · 0.1% 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
£160–£300
If every one of this Gla 220 Amg Line Prem + D 4M A'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
First-time MOT pass rate split by registration band. A 2.3-point gap between bands is modest — the year you buy Mercedes Benz Gla 220 Amg Line Prem + D 4M A makes a small but real difference to MOT outcomes.
Best band to buy
94.7%
2021+ registration
the 2021-on band climbs to 94.7% — a 2.3-point improvement. Tests in this band average 22,962 miles — roughly 7K miles fewer on the clock than the older band. Failures here are mostly wear items: has a cut in excess of the…, damaged but not adversely affecting driver's view — 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
92.4%
2018–2020 registration
On the 2018–2020 band, the data shows a 92.4% pass rate against a fleet average of 94.7% on the newer band. The main culprits logged at test: has a cut in excess of the…, blade defective, and worn down to wear indicator. Average mileage on test for this band is 30,230 miles — high-mileage wear items are a recurring theme.
Best band to buy: 2021+ (94.7% first-time pass). Worst band to avoid: 2018-2020 (92.4% pass). That's a 2.3-point spread across 580 older tests and 1,036 newer ones — year of build makes a material difference on this model.
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
Bosch Aerotwin wiper blades
Cheap wipers fail the test on smear streaks. Bosch Aerotwins last a winter and clear a screen properly.
Search Amazon UK
Item 02 · 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 03 · 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
Affiliate links — small commission, no extra cost to you.
Click Mechanic · affiliate
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.
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 Gla 220 Amg Line Prem + D 4M A 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.
