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10 Most Reliable BMW Engines Ever Built

Oct 04, 2023

BMW is well known for building an incredible range of cars across all automotive segments, and their engines are proving to be pretty dependable too.

BMW's longest serving engine is the 1.5-2.0-liter M10 engine. The wily old inline-four lasted between 1960-1988, a full 28 years of service. Although BMW launched the four-cylinder to power their New Class sedans, the M10 engine successfully led the Bavarian brand from bankruptcy during the '50s; the New Class sedan models also cemented BMW's reputation as a sports sedan manufacturer between 1962-1977, powering the likes of the renowned BMW 2002 Turbo. BMW produced over 3.5 million M10 engines in just under 30 years of production.

However, regarding power, BMW's most powerful engine is the M12/13/1 engine based on the four-cylinder M10. This turbocharged monster saw operation during the 1986 Formula 1 season, powering the likes of the Benetton, Brabham, and Arrows racing teams. The BMW M12 racing engine has a displacement of 1.5 liters and can produce up to 1,400 hp.

Power and longevity are significant indicators of a manufacturer's pedigree. However, here are the most reliable BMW engines, following in the footsteps of the iconic M10 and M12 engines.

BMW released the M54 at the dawn of the 21st century, and the straight-six instantaneously joined the army of grease blocks featured on 'Ward's Best Engines' between 2001-2003. The M54 primarily provided thrust for the polarizing E46 3 Series, such as the 330i. The maximum output from the basic Bavarian is 228 hp and 221 lb-ft of torque; displacement ranges from 2.2 to 3.0 liters.

The M54 is a simple engine from BMW, thus a highly reliable hunk of metal featuring an aluminum block and cylinder head. In addition, the M54 came equipped with cast iron cylinder liners. Providing owners maintain the notoriously fragile VANOS unit, the M54 is one of BMW's most reliable engines.

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Although the BMW S54 serves as the performance variant of the BMWs M54 found in the E46 320i and 320Ci models, the actual engine shares more characteristics with the 1992 BMW S50 performance engine, being that the block itself utilized cast-iron construction in place of aluminum found on the M54 base engine. In fact, the S54 has become one of the most reliable performance engines ever made by BMW, with decades of six-cylinder expertise used in its manufacture. However, some have taken the S54 a little too far.

The BMW S54 straight-six arrived with a 3.2-liter displacement capable of producing 338 hp and 269 lb-ft of torque at 4,900 RPM; this monster powered the best M3 money can buy, and is one of BMWs last naturally aspirated six-cylinder engines, just behind the 2006 N53 which was the final BMW six-cylinder operating a naturally aspirated setup. BMW created its first naturally aspirated six-cylinder in 1968, the BMW M30.

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The N52 straight-six from Bavaria came to light in 2005 and remained until 2015. The highly reliable BMW engine debuted in the E90 3 Series, a series featuring one of BMWs most reliable used cars.

However, back to the N52. The block was BMW's first water-cooled engine, featuring an aluminum cylinder head alongside a magnesium block. This forward-thinking blend of materials made the N52 one of the lightest six-cylinder engines of the time, weighing just 355 lbs. Furthermore, the 3.0-liter N52 engine produces 285 hp and 222 lb-ft of torque in its most potent form. You can find the N52 lurking within impenetrable icons such as the E90 328i.

BMW launched the N55 as a result of the N54s failings. The N54 was their first turbocharged six-cylinder engine sold en-mass; being a bit of a pioneer, the N54 ran into niggling electronics issues and fuel injector failure. However, the N55 arrived with uprated injectors and a single twin-scroll turbocharger instead of the twin-turbocharged setup found on the N55. Think of the N55 as BMW's end product for its six-cylinder power plant. N55-powered cars remain one of the most cost-effective ways to experience a performance BMW with outstanding reliability.

BMW launched the N55 in 2009 with a 3.0-liter displacement capable of 315 hp and 332 lb-ft of torque; perhaps its most potent application is under the hood of the pocket-friendly 335i E92. Some N55 engines have been known to cross 1,000 hp thanks to ever-reliable BMW build quality.

A BMW V8 engine based on the M52 block, the S62 V8, found a home in the 1998-2003 E39 M5. The German V8 churned a mind-numbing 394 hp and 369 lb-ft of torque through the M5's rear wheels. The BMW E39 M5 started the sedan horsepower wars thanks to its bulky S62 V8, which has since become one of the most reliable BMW performance cars ever made.

The BMW 4.9-liter V8 is a highly reliable engine; although some prefer the ticking time bomb that is the F10 M5. And, there's an E39 M5 that achieved 542,000 miles under the tutelage of the sturdy S62 V8 engine. The only issues to look out for are the torrid VANOS units plaguing the BMW range of the era.

Launching in 1990 and holding out until 2000 is another meticulously built six-cylinder engine from BMW, the M50. Displacement for the M50 ranges between 2.0-2.5 liters, and the six-cylinder can quickly produce a modest 189 hp and 184 lb-ft of torque. The M50 is one of the best BMW engines ever manufactured.

The M50 is a masterful example of a BMW six-cylinder. During a period when electronics were not relied on, BMW planted the bulletproof M50 within the larger 520i and 525i E34 sedans of the period and even introduced their notorious VANOS valve timing system on the M50 from the 1992 model year.

RELATED: 1988-1995 BMW 5-Series E34: Costs, Facts, And Figures

The BMW M20 straight-six is an immensely reliable beast, launching in 1977 and gripping on until 1990. The M20 lasted an astonishing 16 years in production, a remarkable testament to one of BMW's most reliable engines.

The straight-six engine configuration is what BMW has become known for, and the M20 played a massive role in building its untouchable reputation when manufacturing six-pot power plants. In fact, the M20 engine powers both the 325i and 525i models of the era, producing a maximum of 169 hp.

The M20 replaced the rather large M30 straight-six BMW engine. The M20 saw a compact, forward-thinking approach with fewer moving parts and minimal electrical components interrupting operation. The simplistic M20 ranged between 2.0-2.7 liters, as the untouchable block powered the iconic E30 3 Series of the '80s.

BMW launched the B58 to replace the venerable N55 turbocharged straight-six. Arriving in 2015, the B58 carried on where the N55 left off as a highly compact six-cylinder reinforced with strong internals expected from the Bavarian brand.

BMW B58 is one of the best engines in the world for its versatility alone, as you can find the 3.0-liter six-cylinder powering an M240i, an X5 SUV, and even a 745E hybrid, as the BMW B58 can happily produce 382 hp and 369 lb-ft of torque, satisfying multiple automotive sectors.

BMW debuted its most versatile block back in 2015, lurking within the F30 340i, and it has since gone on to power the Toyota Supra. Toyota, as a brand, represents reliability; it says a lot when they take on another manufacturer's components.

Replacing the hit-and-miss N20, BMW crafted the B48 in-line four engines for 2015 model year cars. The plucky Bavarian power plant has since become one of the best four-cylinder engines for sale in 2023. BMW launched the B48 on the F56 platform MINI in 2015 with displacements ranging from 1.6-2.0 liters.

Worth noting, BMW models are notoriously expensive when it comes to maintenance costs; CarEdge estimates your average BMW costs $19,312 to repair and maintain over the vehicle's first 10 years. That's over $7,000 more than the industry average for a luxury automotive brand.

However, high costs aside, what makes the B48 stand out is the sheer breadth of its versatility. The little turbocharged block powers the incredibly underrated MINI John Cooper Works series, with up to 302 hp and 332 lb-ft of torque on tap! The engine is almost 10 years old, a testament to its longevity as a performance engine and a daily driving machine, all in the same package.

The M57 is a straight-six diesel engine manufactured by BMW between 1998-2013. The M27 is a highly reliable BMW engine, capable of producing a hefty 428 lb-ft of torque from its cast iron foundations. BMW installed its bulbous diesel in the 335d sedan and early X5 models. In fact, Land Rover even operated the sturdy M27 diesel among its L322 Range Rover series, a mature decision considering what they were up to at the time.

BMW used cast iron to prevent engine vibrations associated with diesel engines from causing damage. In addition, the M27 features forged steel connecting rods and saw BMW operate with chains instead of the notoriously unreliable timing belts on '90s BMW cars.

An automotive writer based in the UK, suffering with an unhealthy obsession for cars and Formula One.​​​Providing commanding content that attracts attention and entertains all at the same time is key.At the weekends, you can find him Driving past Williams Racing making high pitch V10 noises with his mouth.... daring to dream...