BMW Z4 years to avoid — 102,825 MOT tests ranked

No clear negative outlier after correcting for age. Strongest in the data: 2009 or 2010. The ranking uses 102,825 MOT tests across 17 registration years (2023–2025) and compares each year with all UK cars of the same age.

Every Z4 year, ranked

The age-adjusted MOT index sets 100 as the pass rate of all UK cars registered in the same year and tested in the same calendar year. Higher is better. This prevents an old car being labelled a “bad year” simply because it is old.

RankYearIndexVs same-agePass rateTests
1 2009 Strong 116.7 +16.7 pts 83.1% 7,368
2 2010 Strong 115.2 +15.2 pts 82.5% 5,868
3 2011 114.6 +14.6 pts 83.8% 5,863
4 2007 111.6 +11.6 pts 76.8% 9,397
5 2012 111.5 +11.5 pts 82.7% 5,564
6 2006 110.9 +10.9 pts 75.3% 9,082
7 2008 110.0 +10.0 pts 75.1% 5,444
8 2004 109.4 +9.4 pts 73.8% 9,172
9 2013 109.4 +9.4 pts 82.7% 4,688
10 2014 109.3 +9.3 pts 85.2% 5,699
11 2003 107.6 +7.6 pts 72.7% 7,485
12 2015 107.2 +7.2 pts 85.9% 4,720
13 2005 105.5 +5.5 pts 70.1% 6,205
14 2016 103.5 +3.5 pts 84.8% 3,636
15 2019 102.3 +2.3 pts 90.7% 5,982
16 2020 102.1 +2.1 pts 92.0% 4,548
17 2021 101.4 +1.4 pts 91.8% 2,104

How to use this before buying

  • Rankings describe the cohort, not the car. A cherished older example beats a neglected 2009 one — always run the specific reg through the free MOT history check.
  • Read the advisories. Repeated notes for the same component across years mean the owner has been ignoring it. Decode them in our advisory library.
  • Scan before you pay. A 2-minute OBD scan reveals stored faults the dashboard hides — see our scanner guide.

FAQs

Which Z4 years should I avoid?

No year is a clear negative outlier after correcting for age, so buy on condition and history rather than year.

What is the best Z4 year to buy used?

2009 and 2010 lead the age-adjusted MOT ranking. The score compares each registration year with all UK cars of the same age; the specific car's history and condition still take priority.

Is the Z4 reliable overall?

Across 102,825 tests, the median age-adjusted index is 109.4 (100 equals the pass rate of all cars registered in the same year). Use the spread between years as one signal, then check the individual registration.

Methodology: index = 100 + the model-year cohort’s MOT pass-rate difference versus all UK vehicles registered in the same year and tested in the same calendar year. Class 4 initial tests only; retests excluded; at least 1,500 tests per page. “Inspect” years are below both the same-age baseline and the model’s median index by at least 2 points. Association is not proof of a model-year defect. DVSA anonymised data 2023–2025, OGL v3.0.