Two of the most-enquired diesels in the entire Land Rover range, head to head. One is newer, cheaper to fix, and more common. The other has more torque and a defining catastrophic risk. Here's the honest verdict.
The 204DTD Ingenium diesel wins for most buyers — cheaper to replace, more widely supported, and free of the 306DT's defining catastrophic failure mode. The 306DT still makes sense in larger, heavier vehicles where its extra torque and capacity are genuinely used.
Full spec comparison, five-year cost of ownership, the case for each engine, and which to choose for your situation below.
| 204DTD (Ingenium) | 306DT (TDV6/SDV6) | |
|---|---|---|
| Layout | 4-cylinder, 2.0L | V6, 3.0L |
| 2025 UK Enquiries | 1,150 [EM-VERIFIED] | 980 [EM-VERIFIED] |
| Reconditioned S&F | £3,500–£5,800 | £6,500–£9,500 |
| R&R Labour | 10–14 hrs | 15–20 hrs |
| Defining Failure | Pre-2019 timing chain | Crankshaft bearing (catastrophic) |
| Best For | Discovery Sport, Evoque, Velar — lighter applications | Range Rover, Range Rover Sport, Discovery 4 — heavier applications |
For most buyers, the 204DTD is the stronger choice. It generates more enquiries in our data not because it fails more often proportionally, but because it's fitted more widely — and when it does need replacing, the cost is meaningfully lower and the failure mode (pre-2019 timing chain wear) is generally more manageable than the 306DT's catastrophic bearing risk [PATTERN DATA]. That said, the 306DT isn't a bad engine — in a Range Rover or Range Rover Sport, where the vehicle's weight and towing capability actually call for a V6's torque, it remains the right engine for the job, and its replacement cost is still comfortably ✅ Safe against typical host values in that range.
The Ingenium diesel is Land Rover's modern four-cylinder, fitted across Discovery Sport, Evoque, Velar and Discovery 5. Its main documented risk is timing chain tensioner wear on pre-2019 builds, substantially revised from the 2019 model year [EM-INTERVIEW]. Real-world oil dilution from short urban journeys is a genuine secondary consideration — see our Ingenium Oil Dilution page. At £3,500–£5,800 reconditioned, it's the more affordable and more widely available of the two engines to replace, and its lower weight and smaller displacement translate into modestly better real-world fuel economy across most driving patterns. Full specs, fitment and reliability rating live on the 204DTD Knowledge Centre.
The 306DT V6 diesel, sold under both the TDV6 and SDV6 names, is fitted to Discovery 4, Range Rover L405, Range Rover Sport and early Velar D300 examples. Its defining risk is a catastrophic crankshaft bearing failure, typically between 80,000 and 140,000 miles — full detail on our 306DT Crankshaft Bearing Failure page. Despite this, our data shows replacement flags ✅ Safe on the large majority of its typical £10,000–£40,000 host vehicles [EM-VERIFIED]. Where the 306DT earns its keep is refinement and pulling power in heavier applications — towing, loaded off-road use, and motorway cruising with a full cabin are all noticeably more relaxed than the smaller four-cylinder manages. Full specs and fitment on the 306DT Knowledge Centre; the ranking behind both engines' enquiry volumes is in our Engine Failure Index 2026.
Purchase price aside, the practical cost difference between these two engines over a typical five-year ownership window comes down to three things: fuel economy, routine servicing cost, and the probability-weighted cost of a major failure. The 204DTD's smaller displacement and lighter construction give it a modest real-world economy advantage. Routine servicing is also cheaper on the four-cylinder, reflecting both lower parts costs and fewer labour hours per job. The probability-weighted comparison is where the gap widens most: even though the 306DT's failure, when it happens, is more expensive to fix, the 204DTD's own failure mode is common enough across its far larger population that the two roughly offset on frequency — leaving cost-per-incident as the deciding factor, and that favours the 204DTD decisively.
Go 204DTD — it's the only realistic option and a proven, affordable unit once past 2019.
306DT's torque suits the vehicle. Budget for the crank-bearing risk with full service history, not by avoiding the engine.
204DTD, decisively — cheaper parts, cheaper labour, wider specialist availability, and a lower probability-weighted repair bill over five years.
If you plan to keep the vehicle past 150,000 miles, factor in that both engines can reach high mileages reliably with correct maintenance — the deciding factor becomes which vehicle size and towing capability you actually need, not engine longevity alone.
One point worth being explicit about: neither engine is "the reliable one" and the other "the unreliable one" in any simple sense. Both carry a known, documented weak point, and both are capable of covering well over 150,000 miles when maintained correctly. The decision genuinely comes down to matching the engine to the vehicle and use case — a four-cylinder Ingenium is the right amount of engine for a Discovery Sport doing the school run and motorway commuting, while a full-size Range Rover regularly loaded or towing benefits meaningfully from the V6's extra torque, even accounting for its higher failure cost when things do go wrong.
For most buyers, yes — a post-2019 204DTD is cheaper to replace, more common, and free of the catastrophic crankshaft bearing risk that defines the 306DT. The 306DT's advantage is torque and refinement in larger, heavier vehicles, where its extra capacity is genuinely put to use.
The 204DTD is cheaper, at £3,500-£5,800 reconditioned supply and fit versus £6,500-£9,500 for the 306DT, reflecting both the smaller unit and lower labour hours required.
The 306DT carries a well-documented catastrophic crankshaft bearing failure risk, typically 80,000-140,000 miles. The 204DTD's main documented risk, pre-2019 timing chain tensioner wear, is generally less catastrophic and was substantially revised from 2019 onward.
The 204DTD typically costs less to own overall, driven by lower parts prices, wider independent specialist availability, and a lower typical repair bill even before accounting for the lower likelihood of a catastrophic failure.
2,130 Combined EnquiriesBoth engines analysed from real 2025 UK data.
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