Audi A3 Sport TDI (2018)
2018 Audi A3 Sport TDI
CarHunch analysed 136 real MOT records for the 2018 Audi A3 Sport TDI. This breakdown of actual test outcomes — pass rates, defect profiles, mileage data — isn't published anywhere else.
The 2018 Audi A3 Sport TDI is a genuinely reliable diesel, passing its MOT on first attempt 87.4% of the time—comfortably ahead of the UK average of 80%—and not a single vehicle in this cohort has ever recorded a dangerous defect. These cars average just 0.03 failures per test and virtually no advisories, suggesting the engine and emissions systems hold up well.
At 64,786 miles median for a six-year-old car, these A3s have been run fairly gently, so mileage wear isn't inflating the pass rate artificially. If you're considering one, the numbers support it as a solid buy, but run a pre-purchase inspection focused on suspension and steering components (the areas where diesel A3s typically show wear first) rather than powertrain reliability.
What to check before buying a 2018 Audi A3 Sport TDI
Practical pre-purchase checks for this age and model.
- 📋 Check the full MOT history. Look for recurring advisories — slow-building issues like corrosion or brake wear patterns show up years before they become failures. Enter the reg below for a full AI analysis.
- 🔍 Inspect for corrosion in person. Brake pipes, sills, subframes, and chassis legs. Surface rust is normal at this age; structural rust is a serious problem that's expensive to fix and can fail an MOT.
- 🛞 Check tyres and brakes. The most common advisory items at this age. Budget for replacement if they're near the limit — factor this into your offer price.
- 📄 Run an HPI check. The MOT history won't show outstanding finance, insurance write-offs, or stolen status — an HPI check will.
Before you buy a Audi A3 Sport TDI
MOT history is one piece of the puzzle. These checks can reveal what CarHunch can't.
CarHunch may earn a small commission if you buy via these links — at no extra cost to you.
Pass Rate by Fuel Type
| Fuel type | Vehicles | Pass rate | Avg failures |
|---|---|---|---|
| Diesel (99%) | 134 | 87.3% | 0.03 |
| Other (1%) | 1 | 100% | 0 |
| Gas Bi-Fuel (1%) | 1 | 100% | 0 |
Mileage Distribution
Most 2018 Audi A3 Sport TDI vehicles sit in the blue band. If the car you're looking at is outside it, it's either unusually low or high mileage for its age.
Half of all 2018 Audi A3 Sport TDI vehicles fall between 55,399 and 79,340 miles.
2018 Audi A3 Sport TDI — Still on the Road
61 vehicles still getting MOTs in 2025 — 78% of the peak remain.
Based on vehicles from this manufacture year that had at least one MOT test in each calendar year. Data from 2022–2025.
MOT History Averages
Found a specific Audi A3 Sport TDI?
Enter the reg to see its individual MOT history, AI Hunches, and how it compares to this cohort.