Fiat Dethleffs
Reliability, running costs, and MOT data across 4 years from 327 real MOT tests.
Avg Pass Rate
90%
Total Tests
327
Best Year
2018 (94%)
Years Covered
4
About the Fiat Dethleffs
The Fiat Dethleffs has been tested 327 times in 2026 MOT data across 4 model years (2017 to 2020), with an average pass rate of 90%. That's comfortably above the national average of 82%, making it a reliable choice. Available as diesel.
Best and Worst Years
The 2018 model is the most reliable with a 94% pass rate from 118 tests. The 2017 model has the lowest at 86%. The 8 point spread between years means reliability varies somewhat, but no year is dramatically different.
Reliability Trend
Newer FIAT DETHLEFFSs show better MOT pass rates than older ones, with an average improvement of 6 percentage points.
Mileage Across Years
The oldest model in our data (2017) averages 19,963 miles, while the newest (2020) averages 13,034 miles.
Compared to the Fiat brand average of 83%, the Dethleffs performs 7 points better, making it one of the more reliable options in the Fiat range.
Estimated Running Costs
Based on 7,400 miles/year, current fuel prices, and MOT pass rate data. Insurance not included.
Full 2020 detailsHow reliable is the Fiat Dethleffs?
Fiat Dethleffs by Year
Click any year to see detailed running costs, reliability data, and comparisons with similar cars.
Fiat Dethleffs Guides & Articles
Cheapest Cars to Insure in the UK: Insurance Groups 1-10
9 min read
ComparisonPetrol vs Diesel in 2026: Which Actually Costs Less to Own?
8 min read
Running CostsCheapest Cars to Run in 2026: Real Data from 19.8 Million MOT Tests
9 min read
Buying GuideFord Fiesta Common Problems (2026): What to Check Before Buying
13 min read
ReliabilityFord Puma Problems: 7 Issues Owners Report (2026)
13 min read
Checking a specific Fiat Dethleffs?
Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.