Two motorway bruisers, one cleaner MOT record
The Mercedes E-Class and BMW 5 Series are not just posh saloons. They are private-hire workhorses, company-car veterans, airport-run regulars and long-distance commuters. That matters, because the MOT record for cars like this is really a record of use. Big miles, heavy bodies, large wheels, diesel torque, loaded boots and years of motorway grit all leave marks.
The 2024 public UK MOT record gives this fight a clear winner. The Mercedes-Benz E model logged
That is a
The E-Class still has a strong defence. It carries higher average mileage at test: 92,827 miles against the 5 Series at 77,147. That is a meaningful gap. The Mercedes fleet is older and harder-used in the aggregate, and you can see that in the cohort split. But the BMW is not scraping a narrow win from a pampered sample. It leads in every year band.
Pass-rate split
The headline is blunt: BMW wins the first-time pass-rate contest.
The 5 Series sits at 87.15%. The E-Class sits at 82.51%. The fail-rate split points the same way. BMW records a 10.38% fail rate; Mercedes records 14.42%. That is not a rounding-error difference. It is the difference between a premium executive car that usually clears cleanly and one that more often arrives with something the tester cannot ignore.
The Mercedes sample is much larger, which is useful. Nearly half a million E-Class tests give us a deep read across old taxis, estates, diesels, petrols, hybrids and late-model saloons. The BMW sample is smaller but still large enough to take seriously. More than 155,000 tests is not niche-car noise.
Mileage stops this becoming a simple badge victory. The E-Class average test mileage is 92,827. The 5 Series average is 77,147. The Mercedes is carrying 15,680 extra miles into the lane. Some of its lower pass rate is probably the price of harder work.
Still, a buyer choosing between the two has to deal with the market as it is. If the question is which model produced the cleaner 2024 MOT record, the BMW 5 Series is ahead.
Where they fail
The Mercedes E-Class failure pattern looks like a big, heavy executive car doing big, heavy executive-car things. Its top recorded failure reasons are:
- Windscreen or window damaged or seriously discoloured but not adversely affecting the driver’s view: 11,010
- Tyre tread depth not in accordance with the requirements: 10,387
- Suspension pin, bush or joint excessively worn: 8,409
- Tyre cords visible or damaged: 7,755
- Brake pipe damaged or excessively corroded: 6,795
That list should make used buyers slow down. Tyres and glass are normal used-car wear, but suspension wear and brake-pipe corrosion are more serious ownership signals. On older E-Class cars, especially high-mileage diesels and estate cars, the underneath matters more than the badge on the bonnet.
The BMW 5 Series top failures are different:
- Windscreen or window damaged or seriously discoloured but not adversely affecting the driver’s view: 3,139
- Tyre tread depth not in accordance with the requirements: 2,149
- Tyre seriously damaged: 1,971
- Tyre cords visible or damaged: 1,858
- Shock absorber damaged to the extent that it does not function or showing signs of severe leakage: 1,230
BMW’s list is tyre-heavy. That is not a compliment, but it is easier to inspect before buying. You can see worn tyres, mismatched brands, sidewall damage and budget rubber in five minutes. A leaking shock absorber also shows up on a proper ramp inspection, and it is a more predictable repair than a deep corrosion pattern.
Neither car is cheap when it fails. That is the point. A failed budget hatchback can be annoying. A failed executive saloon can turn into four tyres, suspension arms, brake work and alignment before you have even taxed it.
Cohort tells
The cohort split is where the comparison becomes more useful than the headline.
For pre-2018 cars, the Mercedes E-Class recorded 406,201 tests and passed at 81.11%, with average mileage of 101,482. The BMW 5 Series recorded 80,312 tests and passed at 83.98%, with average mileage of 99,499. This is the used-buyer battlefield: older diesels, former company cars, private-hire survivors, big estates and cars now old enough to be maintained by budget rather than service schedule.
BMW wins that older band by 2.87 points. The mileage gap is small here too. The Mercedes has only 1,983 more miles on average, so mileage does not explain away the result. In the cohort most buyers will actually shop, the 5 Series has the cleaner pass-rate record.
The 2018-2020 band makes the BMW case stronger. The E-Class recorded 85,456 tests and passed at 88.72%, with average mileage of 55,030. The 5 Series recorded 70,796 tests and passed at 90.35%, with average mileage of 54,682. The mileage is almost level, and BMW still leads by 1.63 points.
The newest band is even clearer, though smaller. The E-Class 2021+ cohort recorded 4,784 tests and passed at 89.90%, with average mileage of 35,399. The 5 Series 2021+ cohort recorded 4,852 tests and passed at 92.93%, with average mileage of 34,497. BMW leads by 3.03 points.
That is the cleanest part of the whole piece: BMW leads pre-2018, 2018-2020 and 2021+. The Mercedes has the larger fleet and the higher full-sample mileage, but there is no hidden age band where it takes back the result.
Mileage tells
Mileage matters more here than it would in a supermini comparison. These cars were bought to cover distance. A low-mileage E-Class or 5 Series can exist, but it is not the typical story. The typical story is motorway use, airport work, company mileage, diesel torque and a cabin that still looks good enough for the owner to keep pushing the car on.
The full Mercedes average mileage at test is 92,827. The BMW average is 77,147. That makes the E-Class look like the harder-used fleet overall. It also fits the model’s UK role. The E-Class has long been a favourite for private hire and long-distance professional use, especially in diesel form. A car doing that job can be mechanically sound and still accumulate the kind of wear that ruins an MOT pass.
But the cohort view stops mileage becoming a total excuse. In pre-2018 cars, the Mercedes is at 101,482 miles and the BMW is at 99,499. That is close enough to compare directly. BMW still wins. In the 2018-2020 band, the Mercedes average is 55,030 and the BMW average is 54,682. Again, close. BMW still wins. In 2021+ cars, BMW carries slightly lower mileage and wins by a larger margin, but the result is consistent rather than isolated.
The buyer lesson is simple: do not let an E-Class seller hide behind the phrase “all motorway miles”. Motorway miles are better than cold-start school runs, but they still wear tyres, suspension, brake pipes, dampers, wheel bearings and screens. A 5 Series seller does not get a free pass either. The BMW’s tyre and damper pattern says condition still needs checking hard.
The numbers we trust
This comparison uses the 2024 public UK MOT record in src/data/mot-2024/mercedes-benz__e.json and src/data/mot-2024/bmw__5-series.json. The figures above are taken from model-level test counts, pass rates, failure counts, average mileage at test and the by_year_band split.
The failure lists are not buyer folklore. They are the most common recorded reasons for refusal in the 2024 files. For the Mercedes, that means glass damage, tyre tread, suspension wear, damaged tyres and brake-pipe corrosion. For the BMW, it means glass damage, tyre tread, tyre damage, visible cords and leaking or non-functioning shock absorbers.
Those lists should shape the viewing, not replace it. On an E-Class, spend time under the car. Look at brake pipes, rear subframe areas, suspension arms, springs, dust covers and previous corrosion advisories. On a 5 Series, start with tyres, wheel damage, dampers, lamps and any sign that the owner has been buying the cheapest rubber that fits the rim.
The limits are also clear. MOT data does not show service history, repair quality, oil-change discipline, gearbox servicing, battery health, infotainment faults, injector issues, air-suspension bills or whether a car was patched up five minutes before the test. It also groups a broad model family together. A cherished petrol saloon and a worked diesel estate can share a model slug while living very different lives.
Still, the record is useful because it is large, practical and hard to flatter. It catches cars at the point where condition has to meet a legal minimum. For a used executive saloon comparison, that is a valuable reality check.
Buyer read
If you are buying blind from the model-level record, pick the BMW 5 Series. It has the higher first-time pass rate, the lower fail rate and the cleaner cohort story. It wins the older cars, the middle band and the newest band. That is rare in a comparison where one side has a plausible mileage excuse.
The Mercedes E-Class is not a bad result. An 82.51% pass rate from 496,441 tests is strong for a large, premium, high-mileage fleet. The average test mileage is high, and the model’s working-car role explains some of the pain. A well-maintained E-Class with clean brake pipes, decent tyres, quiet suspension and a tidy history is still a serious used buy.
But the BMW is the sharper data pick. The 5 Series records 87.15%, and its failure pattern is easier to pre-screen. Tyres and dampers can be checked before purchase. Brake-pipe corrosion and deeper suspension fatigue on an older Mercedes can be less forgiving once the car is yours.
The E-Class has the mileage alibi. The 5 Series has the MOT result.
On equal condition, equal history and equal price, buy the BMW. Buy the Mercedes when the individual car is clearly better than the average: fewer advisories, proper tyres, clean underside, no repeat corrosion notes and no neglected suspension pattern.