Audi A4 vs BMW 3-Series: the German exec MOT divide
The Audi A4 and BMW 3-Series look like the same buyer’s problem from the outside: German saloon or estate, diesel-heavy used stock, motorway miles, premium parts prices, and plenty of cars now old enough for neglected tyres, tired suspension and cheap pre-sale fixes. The 2024 public UK MOT record says the headline pass-rate fight is basically dead level:
Pass-rate split
Start with the clean number, because it stops the pub argument quickly. The BMW 3-Series is ahead by 0.03 percentage points. Across more than 1.3 million recorded 2024 tests between the two cars, that is a technical lead, not a buying rule.
The A4 recorded
The sharper point is this: the A4 is not rescued by quattro romance, and the 3-Series is not punished by rear-wheel-drive folklore. Both sit around 78.7% first-time pass rate. Both fail often enough to make condition matter more than the advert copy. Both can be bought well, and both can become expensive if the previous owner treated the MOT as a repair list.
Where they fail
The A4’s top failure list reads like an ageing premium commuter with rubber, suspension and basic visibility faults catching up with it. Its biggest recorded reason was windscreen or window damage or serious discolouration not affecting the driver’s view, at 14,447 entries. Close behind came severely deteriorated CV joint boots at 13,083, tyre tread depth at 12,816, fractured or seriously weakened springs at 11,789, and rear registration plate lamp faults at 11,431.
That is a very Audi-shaped list. It is not catastrophic engine failure. It is not gearbox doom. It is the stuff that appears when heavy diesel estates and saloons pile on miles, sit on large wheels, and get run until the next test forces a decision. The CV boot count matters because it points to inspection discipline. A split or deteriorated boot is cheap compared with a contaminated joint, but it is only cheap if somebody catches it early.
The 3-Series has a different flavour. Its biggest recorded reason was the same windscreen or window damage category, but at a much larger 24,779 entries because the BMW sample is bigger. Then came tyre tread depth at 17,359, shock absorber damage or severe leakage at 16,638, lamp faults at 11,645, and tyre cords visible or damaged at 11,046.
That BMW list is harsher on dampers and tyres. The rear-drive myth is too neat, but the MOT record does show the 3-Series putting tyre condition high in the failure story. Tyre tread, visible cords and serious tyre damage all appear in the upper part of the table. A buyer who looks only at service stamps and ignores matching tyres, shoulder wear and suspension leakage is missing the thing the test record keeps shouting about.
Cohort tells
The age-band split is where the tie becomes more useful. Among pre-2018 cars, the BMW 3-Series has the better first-time pass rate: 77.98% against 77.38% for the Audi A4. That is a 0.60-point BMW lead in the largest and most relevant old-car band. It is not massive, but it is more meaningful than the headline 0.03-point split because this is where most used buyers are actually shopping.
In the 2018-2020 band, the BMW stays just ahead: 89.73% versus 89.47% for the A4. Again, the gap is small. The BMW is not running away. But it does show consistency across the two cohorts that carry real volume: older cars and middle-aged used cars.
Then the newest cohort flips. The 2021-on Audi A4 posts 93.76%, while the BMW 3-Series sits at 91.15%. That looks like a useful Audi win until you check the sample sizes: 577 A4 tests and 915 3-Series tests. Those are tiny beside the older bands. Treat the newest result as a signal, not a verdict. A small number of young cars entering test age can swing sharply based on fleet mix, mileage and usage.
The cohort lesson is plain: if you are buying an older one, the BMW has a slight pass-rate edge. If you are buying a nearly new A4 or 3-Series, the individual car matters more than the tiny cohort sample. If you are buying a 2018-2020 car, call it close and inspect the failure pattern rather than arguing about xDrive, quattro or rear-drive purity.
Mileage tells
Average mileage at test is almost identical too, with the BMW slightly higher. The A4 averaged 107,570 miles at test. The 3-Series averaged 109,112 miles. That 1,542-mile gap is small enough that neither car gets to claim a massive toughness advantage from mileage alone.
The age bands add colour. Pre-2018 A4s averaged 114,621 miles at test, while pre-2018 3-Series cars averaged 112,913 miles. In that older cohort, the Audi is carrying slightly more mileage but passing slightly less often. That fits the failure list: CV boots, springs, suspension joints, tyre wear and lights. It is doing big-mile premium-car work, but the wear points are not invisible.
In the 2018-2020 band, the BMW averages 49,357 miles and the A4 averages 47,677. The BMW still passes at 89.73% against the Audi’s 89.47%. Again, small numbers, but the BMW is doing fractionally more mileage and still sitting fractionally ahead. That is the closest thing this comparison has to a BMW win.
For 2021-on cars, the BMW averages 28,831 miles and the A4 averages 26,574. The Audi passes better in that cohort despite lower mileage, but the sample is too small to overwork. What matters on a forecourt is whether the car has been wearing premium tyres evenly, whether the dampers are dry, whether previous MOT advisories were fixed properly, and whether the lighting faults look like one-offs or owner neglect.
The numbers we trust
Here is the hard split.
Audi A4, 2024 public UK MOT record:
- Tests: 491,586
- First-time pass rate: 78.65%
- Fail rate: 16.93%
- Average mileage at test: 107,570 miles
- Pre-2018 pass rate: 77.38% from 440,138 tests
- 2018-2020 pass rate: 89.47% from 50,871 tests
- 2021-on pass rate: 93.76% from 577 tests
- Top failure themes: screen damage, CV boots, tyres, springs, rear plate lamps
BMW 3-Series, 2024 public UK MOT record:
- Tests: 811,923
- First-time pass rate: 78.68%
- Fail rate: 16.30%
- Average mileage at test: 109,112 miles
- Pre-2018 pass rate: 77.98% from 763,858 tests
- 2018-2020 pass rate: 89.73% from 47,150 tests
- 2021-on pass rate: 91.15% from 915 tests
- Top failure themes: screen damage, tyres, shock absorbers, lamps, parking brake efficiency
The public record does not price a repair. It does not know whether a car failed on a cheap lamp or a painful suspension stack. It records what testers saw at the point of test. That is exactly why it is useful. It cuts through brand theatre and shows the common weak points.
The A4’s warning pattern is rubber and underbody wear: CV boots, springs, suspension joints and tyres. The BMW’s warning pattern is tyres, dampers, lamps and parking brake performance. That should change how you inspect each one.
On an A4, get low and look for split boots, greasy joints, tired spring seats, uneven front tyre wear and repeat suspension advisories. On a 3-Series, look hard at damper leakage, tyre shoulder wear, cord exposure, lamp faults and handbrake history. Neither car should be bought on service stamps alone. MOT history matters because it shows whether the same minor faults kept coming back until they became failures.
Buyer read
If two cars are the same age, same price and both have clean histories, choose the one with fewer repeat advisories and better evidence of preventive work. That sounds dull, but it is the correct answer for this pair. The headline pass rates are too close for badge loyalty to do the work.
The BMW gets a tiny nod in the older and 2018-2020 cohorts. The Audi claws back the newest band. The BMW carries slightly higher average mileage across the full record. The Audi’s common failures look more CV-boot and spring-heavy. The BMW’s look more tyre and damper-heavy.
That makes the better buy depend on the individual evidence. A properly maintained A4 with intact boots, recent springs, clean tyres and no repeat lamp nonsense is a better purchase than a tired 3-Series with leaking shocks and mismatched rubber. A clean 3-Series with dry dampers, good tyres and no parking brake drama is a better purchase than an A4 with a long list of deferred suspension advisories.
Use the difference underneath instead. Pick the BMW when the dampers are dry, the tyres are even and the older-car history is cleaner. Pick the Audi when the CV boots, springs, suspension joints and lighting record are tidy. Quattro versus rear-wheel drive makes a better forum thread than buying rule here. The MOT record says condition wins.