Jaguar
XJS
Porsche
911
Jaguar XJS vs Porsche 911: 2025 Comparison
The short answer
The Jaguar XJS offers fuel economy, while the Porsche 911 excels at power instead. Choose the Jaguar XJS if you prioritize fuel economy in daily driving, or the Porsche 911 if power matters more for your needs. Both are covered by real owner reports on CarWizz.
Specs side by side
What owners say
XJS
Overall
Owner sentiment is deeply divided and heavily dependent on the specific model year, engine choice, and ownership expectations. The XJS is widely regarded as a beautiful, classic GT car with significant character and a "raffish" image, offering a unique blend of style and performance for its era. However, long-term owner reports are dominated by discussions of poor reliability, particularly for models produced during the British Leyland era (1970s and early 1980s), which suffer from severe electrical problems, inadequate rust proofing, and complex mechanical issues.
Best version to buy
Models equipped with the later AJ16 4.0L inline-six cylinder engine (found in post-1993 models up to 1996) are frequently cited as the best combination of reliability, parts availability, and refinement. The AJ6 engine is also noted as a good choice, though slightly older.
Known issues
- ⚠Severe rust corrosion: particularly on structural points like jacking points, radius arm mounts, and the rear subframe. Inadequate factory rust proofing, especially on pre-1990s models. Frequency: very frequent.
- ⚠Electrical system failures: brittle, heat-damaged wiring harnesses (especially in the V12 engine bay), Lucas electric component failures, intermittent ignition problems, faulty coaxial cable causing no-start conditions.
- ⚠V12 engine complexity and wear: finicky fuel injection, complex engine electronics, high maintenance requirements, poor fuel economy (cited as low as 10 MPG), inherent wear, concerns about long-term reliability without specialist care.
911
Overall
Sentiment is deeply polarized and varies significantly by generation and model. Long-term ownership satisfaction is frequently described as very high, with many owners reporting the car living up to or exceeding lifelong expectations. The 911 is often cited as a benchmark for driver engagement and is recognized as a highly satisfying vehicle to own.
Best version to buy
997.2 Generation: Specifically praised as the "absolute best modern 911" for combining hydraulic steering, a manual transmission, and a modern enough interior. The 997.1 Turbo is also highlighted as a desirable, proven performance variant with a durable engine and dry-sump oiling.
Known issues
- ⚠Extremely high maintenance and repair costs: Major engine or transmission failure can cost more than the car's value, and parts are exceptionally expensive. Frequency: very frequent.
- ⚠Turbo lag in modern turbocharged engines (991.2, 992): Noted as a significant dynamic flaw, with criticism that reviewers downplay its presence. Frequency: recurrent.
- ⚠Interior material quality and durability: Hard plastics, manual seats in base models, and specific issues like peeling door cards on 991 models left in the sun. Frequency: recurrent.
The verdict
The Jaguar XJS is the better choice for most buyers.
It has better fuel economy on its best-equipped version than the Porsche 911, based on the data above. If power matters more to you than running costs, the Porsche 911 is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the Jaguar XJS or the Porsche 911?
Owner reports show similar reliability sentiment for the Jaguar XJS and the Porsche 911. Check the known issues listed above for specific differences between the two.
Which is better for families, the Jaguar XJS or the Porsche 911?
Data on family-specific factors like cargo space is limited for one or both models, but based on available reports, both are positioned as practical daily drivers. Check the specs table above for seating and body type.
Which has better fuel economy, the Jaguar XJS or the Porsche 911?
The Jaguar XJS is more fuel-efficient on paper: 10.7 L/100km combined versus 11.6-11.8 L/100km for the Porsche 911, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the Jaguar XJS or the Porsche 911?
Exact maintenance costs aren't in our data, but reliability signals above are the closest proxy: fewer reported issues generally means lower repair costs over time.