2003–2009
2010–2019
Two generations of Jaguar's flagship saloon. The X350 is the classic, aluminium‑bodied XJ with traditional V8s; the X351 brought a dramatic redesign, supercharged V6 and V8 engines, and modern tech. Here's which generation makes sense for your budget and driving style.
The X351 is the smarter buy for most buyers - it's more modern, offers better performance and efficiency, and its engines (AJ126, AJ133) are well‑supported. The X350 is a classic with timeless styling and a more traditional driving feel, but it's ageing and parts are becoming harder to find. For everyday luxury and peace of mind, the X351 wins; for a classic Jaguar experience on a budget, the X350 is still a compelling choice.
Full comparison, five‑year cost projection, and which generation fits your driving below.
| XJ X350 (2003–2009) | XJ X351 (2010–2019) | |
|---|---|---|
| Construction | Aluminium monocoque | Aluminium‑intensive (lighter, more rigid) |
| Key Engines | AJ‑V8 4.2 · AJ133 5.0 · 2.7/3.0 diesel | AJ126 3.0 V6 SC · AJ133 5.0 V8 SC · 3.0 diesel |
| 2025 UK Enquiries | [ESTIMATED] ~40 | 151 [EM‑VERIFIED] |
| Typical Recon Fitted Cost | AJ‑V8: £3,000–£5,500; AJ133: £5,500–£9,000 | AJ126: £4,500–£7,500; AJ133: £5,500–£9,000 |
| Defining Failure | AJ‑V8 chain guide wear | AJ126 cooling leaks / AJ133 pre‑2013 tensioner |
| Best For | Classic styling, value, traditional feel | Modern performance, tech, newer models |
Enquiry volumes from 2025 Engine Failure Index. Costs are independent specialist supply‑and‑fit.
The X351 is the better choice for most buyers. It offers a more modern driving experience, better performance, and a wider range of engines – including the brilliant AJ126 supercharged V6. The X351 also benefits from stronger parts availability and a more extensive specialist network. The X350 is a classic – its timeless design and more traditional V8 character are still appealing – but it's older, thirstier, and its parts are becoming scarcer. If you want the latest XJ experience, choose the X351; if you're after a classic on a budget and can handle older car maintenance, the X350 is a great buy.
The X350 (2003–2009) was the first all‑aluminium XJ, a technological marvel that shed weight while improving rigidity. Its engine range included the AJ‑V8 4.2‑litre naturally aspirated (300 PS) and supercharged (400 PS) versions, the AJ133 5.0‑litre V8 introduced in 2009, and 2.7/3.0 V6 diesels. The AJ‑V8 is known for timing chain guide wear, which if ignored can lead to catastrophic failure – see our AJ‑V8 Chain Guide Wear page. The AJ133 pre‑2013 units (found in late X350s) have the same tensioner risk as the X351. Replacement costs are moderate: AJ‑V8 at £3,000–£5,500, AJ133 at £5,500–£9,000. The X350's interior is more traditional, with a wood‑heavy dashboard and analogue dials, appealing to those who prefer classic Jaguar luxury. Full specs on the AJ‑V8 Knowledge Centre and AJ133 Knowledge Centre.
The X351 (2010–2019) was a radical redesign – dramatic styling, a more modern interior, and a focus on performance. Its engine line‑up features the AJ126 3.0‑litre supercharged V6 (340–380 PS), the AJ133 5.0‑litre supercharged V8 (up to 550 PS), and a 3.0‑litre V6 diesel. The AJ126 is the most common; it's known for cooling system leaks (water pump, crossover pipes) – see our AJ126 Cooling System Failure page. The AJ133 pre‑2013 has timing chain tensioner risks – details on AJ133 Chain Tensioner Failure. Replacement costs: AJ126 £4,500–£7,500, AJ133 £5,500–£9,000. The X351 also benefits from a 190kg weight reduction over its predecessor, improving handling and fuel economy. It remains a highly desirable used buy, with 151 enquiries in 2025 [EM‑VERIFIED]. Full specs on the AJ126 Knowledge Centre and AJ133 Knowledge Centre.
The X350's strengths are timeless design, value, and character. Its styling is widely regarded as one of Jaguar's most elegant modern designs, and it offers a more traditional, cosseting interior that many classic car enthusiasts prefer. The X350 is significantly cheaper to buy – a good example can be found for £4,000–£8,000, compared to £10,000–£20,000 for an X351. The AJ‑V8 engine is simpler and cheaper to replace than the newer supercharged units, and its chain guide wear is a known, manageable issue. For those who want a classic luxury saloon and are happy to maintain an older car, the X350 offers incredible value for money. However, parts availability is a growing concern, and fuel economy is notably worse than the X351.
Over a typical 5‑year ownership period, the X351 is roughly £1,500–£2,500 cheaper to run than the X350, despite its higher purchase price. This is driven by better fuel economy (the X351's lighter body and more efficient engines save 10–15% on fuel), lower maintenance costs (parts are more readily available and specialists have more experience with the newer engines), and stronger residual values. The X350's lower purchase price can offset this for the first few years, but after five years, the X351 typically holds its value better, making it the more cost‑effective long‑term choice. For a detailed breakdown, see our engine replacement cost guide.
Choose the X350. It offers timeless looks and a traditional luxury feel at a bargain price. Buy a well‑maintained AJ‑V8 car and budget for chain guide inspection.
Choose the X351. The AJ126 V6 delivers a supercharged thrill, and the car's sharper handling and modern interior make it the better everyday driver.
The X350 is simpler to work on and has a classic feel, but parts are getting harder to find. If you're handy, the X350 can be a rewarding project; otherwise, the X351 is the safer bet.
Whichever you choose, always apply the repair vs replace framework before committing to a major repair – the 60% scrap threshold applies to both.
Generally, yes – the X351's engines (AJ126, AJ133) are more modern and better supported. The X350's AJ‑V8 is simpler but older, and its chain guide wear is a known issue. The X351 also benefits from better electronics and fewer age‑related problems.
The X350's AJ‑V8 is cheaper at £3,000–£5,500, but the X351's AJ126 is £4,500–£7,500. Labour times are similar. The X350's older design can sometimes make parts easier to find, but availability is declining.
Yes – if you appreciate classic Jaguar styling and a traditional luxury feel, the X350 offers incredible value. Just be prepared for higher fuel consumption and potential parts scarcity. A well‑maintained example can be a joy to own.
Jaguar uses a 60% scrap threshold: if the cost of a replacement engine exceeds 60% of the vehicle's market value, it's usually cheaper to scrap the car. We explain this in our repair‑or‑replace framework.
151+ Real Enquiries - data from 2025.
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100% Independent - no manufacturer influence.
Clear Verdict - we name a winner and explain why.
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