Jaguar
XJS
Porsche
928
Jaguar XJS vs Porsche 928: 1994 Comparison
The short answer
The Jaguar XJS offers fuel economy, while the Porsche 928 excels at power instead. Choose the Jaguar XJS if you prioritize fuel economy in daily driving, or the Porsche 928 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.
928
Overall
Sentiment is overwhelmingly positive, characterized by deep emotional attachment and appreciation for its unique character as a grand tourer. Owners consistently describe the driving experience as putting a "massive smile" on their face, praising its high-speed stability, powerful top-end pull, and engaging, visceral feel. The car is noted for its historical significance as a technologically advanced flagship, featuring a front-engine V8 with a rear-mounted transaxle for near 50/50 weight distribution, and for its role in saving the company financially.
Best version to buy
S4 (1987-1991) and GT (1990-1992) models are implicitly favored. The S4 is specifically mentioned for its upgraded 4-piston Brembo brakes, which were shared with the 944 Turbo S.
Known issues
- ⚠Extremely high maintenance and repair costs: described as "very costly," "expensive to maintain," and requiring a significant annual budget. Frequency: very frequent.
- ⚠Age-related component failure: all rubber hoses, plastic parts, and vacuum lines become brittle and require wholesale replacement. Electrical wiring harnesses degrade, leading to difficult-to-diagnose faults. Frequency: very frequent.
- ⚠Engine oil consumption: linked to the hypereutectic aluminum block design, similar to issues in other manufacturers' sleeveless engines. 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 928, based on the data above. If power matters more to you than running costs, the Porsche 928 is worth a closer look instead.
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Frequently asked questions
Which is more reliable, the Jaguar XJS or the Porsche 928?
Owner reports show similar reliability sentiment for the Jaguar XJS and the Porsche 928. Check the known issues listed above for specific differences between the two.
Which is better for families, the Jaguar XJS or the Porsche 928?
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 928?
The Jaguar XJS is more fuel-efficient on paper: 10.7 L/100km combined versus 12 L/100km for the Porsche 928, based on the best-equipped catalogued version of each.
Which is cheaper to maintain, the Jaguar XJS or the Porsche 928?
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.