Fiat Dethleffs
From 412 MOT tests. Above average for its class.
Common MOT failure categories
Pass rate by registration year
What goes wrong?
The most common MOT failure reasons are parking brake efficiency below minimum requirement, an airbag obviously inoperative and service brake efficiency below minimum requirement. The top issue, parking brake efficiency below minimum requirement, caused 7 failures in 2024. Checking tread depth (1.6mm legal minimum, 3mm recommended) before your test can save an unnecessary fail. You can check prices at Black Circles if you need replacements. If you need repairs before retesting, sites like BookMyGarage let you compare local prices.
| parking brake efficiency below minimum requirement | 7 |
| an airbag obviously inoperative | 6 |
| service brake efficiency below minimum requirement | 5 |
| an obligatory rear fog lamp missing, or a front or rear fog lamp inoperative or in the case of a multiple light source more than 1/2 not functioning | 4 |
| engine mil illuminated indicating a malfunction | 4 |
| brake hose bulging under pressure | 4 |
| an srs malfunction indicator lamp (mil) indicates a system malfunction | 3 |
| a lamp missing, inoperative or in the case of a multiple light source more than 1/2 not functioning | 2 |
| wiper blade missing or obviously not clearing the windscreen | 2 |
| a tyre cords visible or damaged | 2 |
How serious are these failures?
Not all MOT failures are equal. 41% of failures are serious: 30.8% are safety issues (brakes, steering, tyre damage) and 10.3% could actually leave you stranded. That's close to the 44.4% average across all models. When it does fail, the average repair bill is around £90.
Fiat Dethleffs on UK roads
The fleet is growing: 113 newly registered in the past year with 26 leaving, a net gain of 87. Currently at its highest numbers ever.
Quarterly breakdown
| Quarter | On road | SORN | New | Gone | Net |
|---|---|---|---|---|---|
| 2025 Q3 | 454 | 14 | +36 | -5 | +31 |
| 2025 Q2 | 426 | 11 | +49 | -0 | +51 |
| 2025 Q1 | 340 | 46 | +10 | -13 | -3 |
| 2024 Q4 | 347 | 42 | +18 | -8 | +10 |
| 2024 Q3 | 358 | 21 | +12 | -0 | +16 |
| 2024 Q2 | 356 | 7 | +37 | -1 | +36 |
| 2024 Q1 | 312 | 15 | +8 | -10 | -2 |
| 2023 Q4 | 299 | 30 | +6 | -4 | +2 |
Source: DfT vehicle licensing statistics, 2025 Q3. Crown copyright, OGL v3.0.
By registration year
| Year | Pass rate | Top failures |
|---|---|---|
| 2019 | 87.7% | an airbag obviously inoperative, an srs malfunction indicator lamp (mil) indicates a system malfunction |
| 2018 | 91.7% | engine mil illuminated indicating a malfunction, a tyre cords visible or damaged |
Typical mileage
Half of all Dethleffss tested had between 8,913 and 21,318 miles on the clock. Relatively low mileage overall. Many are still fairly young.
At 16,372 median miles, the Dethleffs has 0.071 failures per 10,000 miles driven.
Other Fiat models
| Fiat 500 | 75% |
| Fiat Ducato | 75.4% |
| Fiat Panda | 71.7% |
| Fiat Punto | 65.7% |
| Fiat Doblo | 71.6% |
Common questions
What is the Fiat Dethleffs MOT pass rate?
The Fiat Dethleffs has a 88.3% MOT pass rate based on 412 real MOT tests. This is above the national average.
What are common MOT failures on a Fiat Dethleffs?
The most common MOT failure on the Fiat Dethleffs is parking brake efficiency below minimum requirement, which caused 7 failures. Other common issues include an airbag obviously inoperative.
How many Fiat Dethleffss are on UK roads?
There are 454 Fiat Dethleffss currently licensed on UK roads, with 14 on SORN.
What is the typical mileage of a Fiat Dethleffs at MOT?
The median mileage at MOT for a Fiat Dethleffs is 16,372 miles. The middle 50% of vehicles tested have between 8,913 and 21,318 miles.
Buying a used Dethleffs?
Start with the free tools. Look up the specific vehicle's MOT history on GOV.UK The mileage at each test will show if it's been wound back, and the advisory history tells you what's wearing. Cross-reference that against the typical failures above to see if anything looks unusual for this model.
The free data won't tell you about outstanding finance, theft markers, or write-off history. For that, you need a vehicle history check This is especially important on a private sale where you have fewer legal protections.
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MOT data from DVSA anonymised test results, 2024 test year. Fleet data from DfT vehicle licensing statistics. Crown copyright, OGL v3.0. MOT pass rates are statistical summaries of test outcomes, not assessments of individual vehicle safety or condition. Always inspect a vehicle and check its full MOT history before purchasing. See terms of use.