Which BMW Petrol Engines are the Most Reliable? 7+ Top-Rated Options Explained
Image source: BMW B58B30C Complete Engine from MT Auto Parts
Why Reliability Matters When Choosing a BMW Engine
When you buy a BMW, you expect more than just a car. You expect precision, performance, and an engine that delivers without constant headaches. BMW is a premium brand, and it has to deliver it. But not every engine is the same. Some are known for long life and minimal repairs, while others gain a reputation for costly faults. Over time, BMW improved many engines, but in this article, we want to take a look at the most reliable ones in terms of repairs, reliability and longevity.
Choosing the right petrol engine can make the difference between years of smooth driving and endless garage visits. This guide breaks down the most reliable BMW petrol engines of recent decades, highlighting their strengths, common issues, where to find quality replacements and other important information.
Signs of a Reliable BMW Engine
Reliable BMW engines tend to share certain qualities:
Strong construction with durable internals.
Efficient cooling systems that prevent overheating.
Refined technology has been developed over multiple generations.
Positive service history backed by real driver reports.
These traits separate the good from the great. Below, we’ll explore the top BMW petrol engines that owners and technicians consistently rate as one of the best.
1. BMW B58 (B58B30A / B58B30C) — The Modern Engine, Our Favourite Beast
Introduced in 2015, the B58 engine quickly set a new standard. Its closed-deck block design adds strength, making it both powerful and durable. You’ll find the BMW B58 engine in a wide range of models, including the 340i (F30/F31), 440i (F32/F33/F36), 540i (G30/G31), 740i (G11/G12), X3 M40i (G01), X4 M40i (G02), X5 xDrive40i (G05), X6 xDrive40i (G06), X7 xDrive40i (G07), Z4 M40i (G29), even Toyota Supra GR (A90/A91) and newer 2 Series M240i (G42) models.
Why drivers love this engine:
Smooth, refined power delivery
Fewer oil leak and timing chain issues compared to older six-cylinders
Regular servicing (oil changes, spark plugs) keeps it running strong for years.
Many owners report effortless highway cruising well past 100,000 miles without major issues. Enthusiasts even say once they’ve owned a B58, they often look for another car with another engine.
2. BMW B48 (B48A20A / B48A20B / B48A20E) — Four-Cylinder Strength, Our Favourite For More Economical Rides
The B48 BMW four-cylinder engine is the top engine for efficiency and everyday use. It offers excellent reliability in a compact package.
You’ll find the BMW B48 engine in a broad range of models, including the 118i/120i (F20/F21, F40), 220i/230i (F22/F23, G42), 320i/330i (F30/F31, G20/G21), 420i/430i (F32/F33/F36, G22/G23/G26), 520i/530i (G30/G31), 730i/740i (G11/G12), X1 20i/25i (F48/U11), X2 20i/25i (F39), X3 20i/30i (G01), X4 20i/30i (G02), Z4 20i/30i (G29), and even in the Toyota Supra 2.0 (A90).
Highlights:
Smooth running with minimal vibration
Longevity: B48A20-series engines regularly pass more than 100,000 miles
Continuous refinements make newer versions even stronger
If you want an economical yet durable BMW engine, the B48 is a smart pick and one of our favourites.
3. BMW S55 (S55B30) — Twin-Turbo M Power Engine
Performance fans know the S55 from the M3 and M4 models. With twin turbos, it delivers serious power while retaining everyday usability.
You’ll find the S55 engine in high-performance models such as the M3 (F80), M4 Coupé and Convertible (F82/F83), and the M2 Competition and M2 CS (F87).
Reliability notes:
Rare crank hub issues, but preventable with upgrades
Strong cooling keeps it safe under hard driving
Handles tuning well when maintained correctly
The S55 is proof that BMW’s M division can balance thrill with dependability.
4. BMW N55 (N55B30A) — Proven Reliability With Six Cylinders
Before the B58, the BMW N55 engine carried BMW’s inline-six reputation. Unlike the twin-turbo N54, the N55 uses a single turbo, reducing failure points. Output sits comfortably around 300+ horsepower across many models. You’ll find the BMW N55 engine in models such as the 135i (E82/E88), 335i (E90/E91/E92/E93, F30/F31), 435i (F32/F33/F36), 535i (F10/F11), 640i (F06/F12/F13), 740i (F01/F02), X1 xDrive35i (E84), X3 xDrive35i (F25), X4 xDrive35i (F26), X5 xDrive35i (E70/F15), X6 xDrive35i (E71/F16), and the Z4 sDrive35i/sDrive35is (E89).
Key reliability points:
Common issues that might appear (water pumps, gasket wear)
Strong longevity — many engines exceed 100,000 miles with ease
Flexible for mild tuning without hurting durability
For those seeking a balance of power and simplicity, the N55 remains a safe bet.
5. BMW S58 (S58B30A) — The New M Standard Engine
Powering the latest M3 and M4, the S58 engine is BMW’s modern performance flagship. Based on the B58 but enhanced, it offers more strength, cooling, and responsiveness.
You’ll find the S58B30A engine in models such as the X3 M (F97), X4 M (F98), M3 (G80/G81), and M4 (G82/G83).
Why it stands out:
Instant throttle response with minimal lag
Built for both everyday driving and track use
Tuned versions still show excellent longevity
For anyone buying a new-generation M car, the S58 is the engine to beat.
6. BMW S63 (BMW S63B44B Engine) — V8 Strength
For drivers who want muscle, the BMW S63B44B engine, V8, found in the M5, X5M, and X6M delivers true power. Early versions had heat-related quirks, but the later S63TU resolved most issues.
Pros:
Reinforced internals and upgraded cooling
Long lifespan when serviced on schedule
Exceptional performance, especially in the TU versions
Yes, it’s thirstier on fuel and maintenance is pricier, but the payoff in power and reliability makes it worthwhile.
7. BMW N52 (N52B25A / N52B30A / N52B30O0) — Naturally Aspirated Classical Engine
Not everyone wants turbo power. The N52, built from 2004–2015, is a naturally aspirated six-cylinder engine with a magnesium block for weight savings.
You’ll find the N52 engine in several UK-market BMWs, including the 125i and 130i (E81/E82/E87/E88), 325i and 330i (E90/E91/E92/E93), 528i and 530i (E60/E61), 630i (E63/E64), 730i (E65/E66), X3 2.5i/3.0i (E83), X5 3.0i (E70) and the Z4 2.5i/3.0i (E85/E86, later E89 in 23i/30i versions).
What makes it reliable:
No turbo = fewer heat and carbon buildup problems
Simpler design keeps maintenance costs low
Only common failures are water pumps and seals at high mileage
Drivers value the N52 for its smoothness, old-school feel and dependable long-term ownership.
Final Thoughts: Choosing the Right BMW Engine
From the modern B58 to the classic N52, BMW has built petrol engines that combine performance with dependability. The key is choosing the right one for your needs and maintaining it with genuine BMW parts.
At MT Auto Parts, we specialise in complete BMW petrol engines and OEM components for F, G and U generation models (2012+). Use our vehicle selector tool on our website, mtautoparts.com or share your BMW VIN for exact compatibility. Explore our full stock of BMW engines for sale today.
FAQs
Which BMW petrol engine is the most reliable?
The BMW B58 (B58B30A / B58B30C) is widely regarded as the most reliable modern BMW petrol engine. Thanks to its closed-deck block, stronger internals and fewer timing chain or oil issues compared to older six-cylinders, it has proven to deliver long service life with proper maintenance.
Is the BMW N52 a good engine to buy today?
While it is an older BMW engine, the BMW N52 remains one of the best naturally aspirated straight six cylinder engines ever made. In the UK, it was fitted to models like the 325i, 330i, 528i, 530i, and Z4. With no turbo to worry about, the N52 is simpler and cheaper to maintain, making it a strong option for buyers who want reliability over outright performance.
Which BMW M engines are the best ones?
Among BMW’s M powerplants, both the S55 (F80 M3, F82/F83 M4, M2 Competition) and the newer S58 (G80 M3, G82 M4, X3M, X4M) have a reputation for being durable when serviced correctly. They deliver high power without sacrificing long-term reliability, provided cooling systems and crank hub upgrades (for S55) are addressed.
Is the BMW N55 still worth considering?
Absolutely. The BMW N55 (N55B30A) is a proven single-turbo straight-six found in cars like the 335i, 435i, and 535i. It is less complex than the twin-turbo N54, easier to maintain and well-known for running well past 100,000 miles with regular servicing.
Which BMW petrol engine should I choose for daily use?
For everyday reliability and economy, the B48 (B48A20 series) is the best choice in our opinion. It powers many modern BMWs, such as the 1 Series, 3 Series, and X1/X3 models. Owners praise its balance of efficiency, smoothness and long-lasting durability.
Disclaimer: The information in this guide is based on general reports, industry data and common workshop experience. Reliability can vary between individual vehicles depending on age, mileage and maintenance history. Always consult a qualified BMW specialist before making purchase decisions.
