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Engine reliability insights, buying guides, and technical deep dives.
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Head-to-Head Comparisons
25Two engines, side by side — scores, faults, and which to buy.
EA837 vs EA839: When Audi's Newer V6 Is the Riskier Buy
Audi's supercharged 3.0 EA837 scores 84/100; the newer turbocharged EA839 3.0 scores just 65/100. A rare case where the older engine is the safer used purchase — here's why.
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EA888 Gen 1/2 vs Gen 3: The €3,000 Oil Habit VW Finally Fixed
The early EA888 2.0 TSI burned oil and ate timing-chain tensioners; the Gen 3 fixed both. Gen 1/2 scores 38/100 (AVOID), Gen 3 scores 84/100 (BUY). Which years to buy.
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EA113 vs EA888: The Old Hot-Hatch Heart vs Its Successor
The EA113 2.0T powered the Mk5 GTI, S3 and A4 but hides one cheap-yet-deadly flaw; the EA888 Gen 3 replaced it. EA113 scores 73/100 (ACCEPTABLE), EA888 Gen 3 scores 84/100 (BUY). What used buyers must check.
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B57 vs M57: BMW's Diesel Six, 18 Years Apart
The M57 is the cult-classic BMW straight-six diesel; the B57 is its modern, 400 hp successor. Both score in BUY territory; the M57 has its early swirl flaps to check, the B57 one recall-backed fault. Which deserves your money?
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B58 vs B57: BMW's Petrol Icon vs Its Diesel Workhorse
Same 3.0-litre block, opposite fuels. BMW's B58 petrol six scores 89/100 (BEST); the B57 diesel scores 82/100 (BUY). A buyer's guide to choosing by how you actually drive.
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N52 vs N53: The Same BMW Six, 29 Points Apart
The N52 is one of BMW's most reliable naturally-aspirated sixes; the near-identical-looking N53 is a costly gamble. N52 scores 81/100 (BUY), N53 scores 52/100 (CAUTION). Know which you're buying.
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N54 vs B58: BMW's Turbo Six, From Cautionary Tale to Icon
The N54 made huge power but broke often; the B58 makes more and barely breaks at all. N54 scores 42/100 (AVOID), B58 scores 89/100 (BEST). The full reliability gap.
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B48 vs B58: Do You Actually Need the Six?
BMW's 2.0 four-cylinder B48 scores 82/100 (BUY); the 3.0 six-cylinder B58 scores 89/100 (BEST). Both excellent — here's how to choose between a 320i and a 340i on reliability, cost and character.
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N57 vs M57: BMW's Diesel Six — the Middle Child vs the Legend
The M57 is the cult-classic BMW diesel six; the N57 is the generation that replaced it. M57 78/100 (BUY), N57 69/100 (ACCEPTABLE) — the N57 carries the EGR-cooler fire recall and bearing-wear reports. Which one to buy used.
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N63 vs B58: More Cylinders, More Problems
BMW's original 4.4 V8 N63 scores 43/100 (AVOID) and the revised N63TU 62/100; its 3.0 straight-six B58 scores 89/100 (BEST). The 'hot-V' twin-turbo V8 cooks its own injectors — here's why the smaller engine is the far smarter buy.
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N63 vs M278: Which Engine is More Reliable?
N63 scores 43/100 vs M278 at 59/100. Full comparison with known issues and repair costs.
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B47 vs N47: Which Engine is More Reliable?
B47 scores 80/100 vs N47 at 54/100. Full comparison with known issues and repair costs.
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B48 vs N20: Which Engine is More Reliable?
B48 scores 82/100 vs N20 at 58/100. Full comparison with known issues and repair costs.
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N52 vs M54: Which Engine is More Reliable?
N52 scores 81/100 vs M54 at 86/100. Full comparison with known issues and repair costs.
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N54 vs N55: Which Engine is More Reliable?
N54 scores 42/100 vs N55 at 79/100. Full comparison with known issues and repair costs.
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N55 vs B58: Which Engine is More Reliable?
N55 scores 79/100 vs B58 at 89/100. Full comparison with known issues and repair costs.
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OM613 vs OM648: Two 3.2 Mercedes Sixes, Same 84/100 Score
The OM613 and OM648 are both 3.2-litre straight-six CDIs and both now score 84/100 (BUY). What actually separates them is the fault list, the years and the cars — here's how to choose.
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OM642 vs OM656: Why Mercedes Abandoned the V6 Diesel
The OM642 V6 scores 65/100, the OM656 straight-six 82/100 — and they fail in completely different ways. An engineering look at Mercedes' switch back to the inline-six, and which to buy.
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OM651 vs OM654: Mercedes' Troubled Diesel and Its Successor
The OM651 dented Mercedes' diesel reputation; the OM654 is better but not trouble-free. Early OM651 scores 66/100 (CAUTION), OM654 scores 76/100 (ACCEPTABLE). Full data, costs, and which years to buy.
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M273 vs M113: The Mercedes V8 That Lasts vs the One With a Soft Gear
The older M113 is a bulletproof Mercedes V8; the M273 that replaced it has a costly idler-gear defect on early engines. M113 scores 89/100 (BEST), M273 scores 66/100 (CAUTION). Which to buy used.
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OM648 vs OM606: Mercedes' Two Diesel Legends, Head to Head
The OM606 and OM648 both score 84/100 and are two of the toughest Mercedes diesels we've scored. One is mechanical and pre-electronic, the other a refined common-rail six. Which era should you buy?
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M271 Kompressor vs M271 EVO: Two Engines, One Name — Which Mercedes 1.8 Do You Actually Have?
Mercedes sold two very different 1.8-litre fours under the M271 badge. The supercharged Kompressor (2002–2011) scores 35/100 (AVOID); the turbo EVO (2009–2015) scores 58/100 (CAUTION). How to tell them apart, what breaks on each, and what it costs in euros.
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OM654 vs B47: Which Engine is More Reliable?
OM654 scores 76/100 vs B47 at 80/100. Full comparison with known issues and repair costs.
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EP6/THP (Prince) vs EA211 1.4 TSI: Which Engine is More Reliable?
EP6/THP (Prince) scores 40/100 vs EA211 1.4 TSI at 78/100. Full comparison with known issues and repair costs.
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EA189 vs EA288: Dieselgate and the Diesel That Came After
The EA189 is the engine at the centre of Dieselgate; the EA288 is its successor. EA189 scores 62/100 (CAUTION), EA288 scores 69/100 (ACCEPTABLE). What used buyers need to know.
Read more →Engines to Avoid
12Known-problem engines, by brand. Read before you buy.
Audi Engines to Avoid: Reliability Scores & Known Problems
Which Audi engines have the worst reliability? Data-backed scores and known issues for 6 low-scoring Audi engines.
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BMW Engines to Avoid: Reliability Scores & Known Problems
Which BMW engines have the worst reliability? Data-backed scores and known issues for 16 low-scoring BMW engines.
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Fiat Engines to Avoid: Reliability Scores & Known Problems
Which Fiat engines have the worst reliability? Data-backed scores and known issues for 2 low-scoring Fiat engines.
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Ford Engines to Avoid: Reliability Scores & Known Problems
Which Ford engines have the worst reliability? Data-backed scores and known issues for 3 low-scoring Ford engines.
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Hyundai/Kia Engines to Avoid: Reliability Scores & Known Problems
Which Hyundai/Kia engines have the worst reliability? Data-backed scores and known issues for 5 low-scoring Hyundai/Kia engines.
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Mercedes-Benz Engines to Avoid: Reliability Scores & Known Problems
Which Mercedes-Benz engines have the worst reliability? Data-backed scores and known issues for 8 low-scoring Mercedes-Benz engines.
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Nissan Engines to Avoid: Reliability Scores & Known Problems
Which Nissan engines have the worst reliability? Data-backed scores and known issues for the lowest-scoring Nissan engine.
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Opel Engines to Avoid: Reliability Scores & Known Problems
Which Opel engines have the worst reliability? Data-backed scores and known issues for the lowest-scoring Opel engine.
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PSA Engines to Avoid: Reliability Scores & Known Problems
Which PSA engines have the worst reliability? Data-backed scores and known issues for 7 low-scoring PSA engines.
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Porsche Engines to Avoid: Reliability Scores & Known Problems
Which Porsche engines have the worst reliability? Data-backed scores and known issues for the lowest-scoring Porsche engine.
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Renault Engines to Avoid: Reliability Scores & Known Problems
Which Renault engines have the worst reliability? Data-backed scores and known issues for 6 low-scoring Renault engines.
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Volkswagen Engines to Avoid: Reliability Scores & Known Problems
Which Volkswagen engines have the worst reliability? Data-backed scores and known issues for 9 low-scoring Volkswagen engines.
Read more →Most Reliable by Brand
17The top-scoring engines from each manufacturer.
Most Reliable Audi Engines: Complete Ranking with Scores
Which Audi engines are the most reliable? Data-backed ranking of 10 Audi engines scoring 78/100 or higher.
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Most Reliable BMW Engines: Complete Ranking with Scores
Which BMW engines are the most reliable? Data-backed ranking of 14 BMW engines scoring 78/100 or higher.
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Most Reliable Fiat Engines: Complete Ranking with Scores
Which Fiat engines are the most reliable? Data-backed ranking of 6 Fiat engines scoring 78/100 or higher.
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Most Reliable Ford Engines: Complete Ranking with Scores
Which Ford engines are the most reliable? Data-backed ranking of 12 Ford engines scoring 78/100 or higher.
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Most Reliable Honda Engines: Complete Ranking with Scores
Which Honda engines are the most reliable? Data-backed ranking of 14 Honda engines scoring 78/100 or higher.
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Most Reliable Hyundai/Kia Engines: Complete Ranking with Scores
Which Hyundai/Kia engines are the most reliable? Data-backed ranking of 15 Hyundai/Kia engines scoring 78/100 or higher.
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Most Reliable Mazda Engines: Complete Ranking with Scores
Which Mazda engines are the most reliable? Data-backed ranking of 6 Mazda engines scoring 78/100 or higher.
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Most Reliable Mercedes-Benz Engines: Complete Ranking with Scores
Which Mercedes-Benz engines are the most reliable? Data-backed ranking of 18 Mercedes-Benz engines scoring 78/100 or higher.
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Most Reliable Nissan Engines: Complete Ranking with Scores
Which Nissan engines are the most reliable? Data-backed ranking of 10 Nissan engines scoring 78/100 or higher.
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Most Reliable Opel Engines: Complete Ranking with Scores
Which Opel engines are the most reliable? Data-backed ranking of 6 Opel engines scoring 78/100 or higher.
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Most Reliable PSA Engines: Complete Ranking with Scores
Which PSA engines are the most reliable? Data-backed ranking of 7 PSA engines scoring 78/100 or higher.
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Most Reliable Porsche Engines: Complete Ranking with Scores
Which Porsche engines are the most reliable? Data-backed ranking of 5 Porsche engines scoring 78/100 or higher.
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Most Reliable Renault Engines: Complete Ranking with Scores
Which Renault engines are the most reliable? Data-backed ranking of 15 Renault engines scoring 78/100 or higher.
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Most Reliable Suzuki Engines: Complete Ranking with Scores
Which Suzuki engines are the most reliable? Data-backed ranking of 9 Suzuki engines scoring 78/100 or higher.
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Most Reliable Toyota Engines: Complete Ranking with Scores
Which Toyota engines are the most reliable? Data-backed ranking of 20 Toyota engines scoring 78/100 or higher.
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Most Reliable Volkswagen Engines: Complete Ranking with Scores
Which Volkswagen engines are the most reliable? Data-backed ranking of 15 Volkswagen engines scoring 78/100 or higher.
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Most Reliable Volvo Engines: Complete Ranking with Scores
Which Volvo engines are the most reliable? Data-backed ranking of 5 Volvo engines scoring 78/100 or higher.
Read more →Most Reliable by Type
1Best engines by fuel and configuration.
Buying Guides
11Model and engine deep-dives for used buyers.
Audi A4 Engine Guide: Is the Badge Worth the Premium? Every B7, B8, and B9 Engine Rated
The A4 shares engines with the Golf and Passat — but costs 30% more to buy and maintain. Which A4 engines justify the premium and which make it a money pit.
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BMW N47 Timing Chain Problems: What Every Buyer Must Know
The BMW N47 2.0 diesel has a fatal flaw — a rear-mounted timing chain that stretches and fails. Here's what to check before buying a 320d or 520d.
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Buying a BMW E90? The Engine Code Matters More Than the Mileage
The E90 3 Series is an engine lottery — scores range from 42/100 to 81/100. Here's how to pick the right one and avoid a money pit.
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BMW F30 3 Series: Which Engine and Year to Choose
The BMW F30 came with 8 different engines ranging from 54/100 to 89/100. Here's which engine and year combination gives you the most reliable 3 Series.
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Honda Civic Engine Guide: The Commuter That Moonlights as a Legend
The Civic is two cars in one — sensible daily and performance icon. Every engine from the EJ/EK to the FL5 scored for reliability and real-world ownership.
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Mazda3 Engine Guide: Why Mazda Ignored the Turbo Trend and Won
While VW and BMW chased turbo downsizing, Mazda bet on naturally aspirated Skyactiv engines. The Mazda3 reliability data proves they were right.
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Skoda Octavia Engine Guide: The Spreadsheet Winner of the VW Group
Same engines as the Golf and A4, Passat-sized interior, 30% less money. Every Octavia engine rated — and why the Octavia is the rational choice nobody regrets.
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Every Toyota Corolla Engine Rated: Why It's the Safest Used Car Buy in Europe
No Corolla engine scores below 74/100. Here's why the Corolla is the lowest-risk used car purchase — and which engine-generation combo is best.
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VW Golf Engine Guide: Every Generation from Mk4 to Mk8, Ranked by Reliability
From the legendary 1.9 TDI to the problematic EA111 TSI — every Golf engine scored and ranked. Which Golf generation and engine to buy used.
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VW Passat Engine Guide: The Motorway Car Where Engine Choice Defines Total Cost
The Passat eats kilometres. But a B6 with the wrong engine costs more to maintain than a B8 with the right one. Every Passat engine scored from B5+ to B8.
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Turbo vs Naturally Aspirated: Which Engines Last Longer?
We compared reliability scores of 265 engines. Naturally aspirated engines score higher on average — but the best turbos are catching up. Here's the data.
Read more →By Engine Size
3The most reliable engines under 1.4L, 1.6L and 2.0L.
Most Reliable Engines Under 1.4L: Complete Ranking
39 engines under 1.4L scored by reliability. Data-backed ranking with issues and repair costs.
Read more →Most Reliable Engines Under 1.6L: Complete Ranking
75 engines under 1.6L scored by reliability. Data-backed ranking with issues and repair costs.
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Most Reliable Engines Under 2.0L: Complete Ranking
131 engines under 2.0L scored by reliability. Data-backed ranking with issues and repair costs.
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