Discovering Which Bmw Models Feature The N55 Engine

Picture this: You’re at a car meet, admiring a sleek BMW, and the conversation turns to engines. Someone mentions the N55, a legendary powerplant known for its balance of power and refinement. Suddenly, you wonder, “what BMW has the N55 engine?” It’s a common question for enthusiasts and prospective buyers alike, as this particular engine has powered a wide range of popular models. Knowing which vehicles house this celebrated inline-six can be crucial, whether you’re hunting for your next daily driver, a weekend track toy, or just deepening your BMW knowledge. This comprehensive guide will meticulously list every significant BMW model equipped with the N55 engine, detailing its characteristics, common considerations, and its enduring legacy, helping you confidently navigate the world of BMW.

The Power Behind the N55 Engine: A Deep Dive

The BMW N55 engine marked a significant evolution in the automaker’s inline-six gasoline engine lineage. Introduced as a successor to the acclaimed but complex N54, the N55 aimed to deliver comparable performance with improved efficiency and reliability. This section will explore the core technologies that define the N55, understanding why it became a favorite among enthusiasts and a workhorse across various BMW platforms. We’ll delve into its unique architecture and the innovations that set it apart.

N55 Engine Architecture and Key Technologies

TwinPower Turbo Technology
Unlike its twin-turbocharged N54 predecessor, the N55 introduced BMW’s “TwinPower Turbo” concept, which in this context refers to a single, twin-scroll turbocharger. A twin-scroll turbo segregates the exhaust pulses from pairs of cylinders, guiding them through separate spirals (scrolls) to the turbine. This design significantly reduces exhaust gas interference, leading to more efficient energy recovery, quicker spooling, and improved low-end torque. The result is a smooth, linear power delivery that feels responsive across the entire RPM range, minimizing turbo lag and enhancing the overall driving experience compared to traditional single-scroll units.
High-Precision Direct Injection (HPDI)
Direct injection is a crucial technology in modern internal combustion engines, and the N55 utilizes BMW’s High-Precision Direct Injection system. Instead of injecting fuel into the intake manifold, HPDI sprays fuel directly into the combustion chamber at high pressure. This precise fuel delivery allows for more accurate air-fuel mixture control, leading to improved fuel efficiency, reduced emissions, and enhanced power output. By atomizing fuel more effectively and placing it directly where combustion occurs, HPDI contributes significantly to the N55’s impressive thermal efficiency and specific power output, ensuring more complete and cleaner combustion.
Valvetronic Variable Valve Lift System
Valvetronic is BMW’s innovative variable valve lift system, designed to control the amount of air entering the engine by continuously varying the intake valve lift, rather than relying solely on a conventional throttle body. By eliminating the throttle plate as the primary means of air regulation under most driving conditions, Valvetronic reduces pumping losses – the energy wasted by the engine having to pull air past a partially closed throttle. This technology significantly improves fuel economy and throttle response, making the N55 both more efficient and more enjoyable to drive, offering a smoother and more immediate reaction to accelerator pedal inputs.
Double-VANOS Variable Valve Timing
Double-VANOS (Variable Nockenwellen Steuerung) is BMW’s continuously variable valve timing system, which precisely adjusts the timing of both the intake and exhaust camshafts. By independently varying valve overlap and lift duration, Double-VANOS optimizes engine breathing for different RPMs and load conditions. At low RPMs, it enhances torque and fuel efficiency, while at higher RPMs, it improves horsepower and throttle response. This dynamic adjustment contributes to the N55’s broad power band, allowing it to deliver strong performance from idle to redline, while simultaneously reducing emissions and enhancing overall engine flexibility.

Evolution from N54 to N55

Single Turbo vs. Twin Turbo Configuration
The most immediate difference between the N54 and N55 engines is their turbocharging setup. The N54 famously used two smaller turbochargers, one for each bank of three cylinders, contributing to its aggressive top-end power. The N55, however, adopted a single, twin-scroll turbocharger. This change simplified the exhaust manifold design, reduced complexity, and aimed to improve low-end response and efficiency, making the power delivery smoother and more linear for everyday driving while still retaining impressive peak output figures.
Integration of Valvetronic
A key technological advancement in the N55 was the integration of BMW’s Valvetronic system, which was absent in the N54. Valvetronic’s continuously variable intake valve lift replaced the traditional throttle body as the primary means of air control. This innovation dramatically improved fuel efficiency by reducing pumping losses and sharpened throttle response. The N54, while powerful, could not match the N55’s efficiency and responsiveness due to its reliance on a conventional throttle plate for air metering, making the N55 a more refined and economical engine.
Focus on Reliability and Manufacturing Simplicity
BMW designed the N55 with an eye towards improving manufacturing efficiency and long-term reliability compared to the N54. By simplifying the turbo system, integrating Valvetronic, and refining other components, the N55 benefited from fewer parts and a less complex layout. This shift aimed to address some of the N54’s known issues, such as wastegate rattle and high-pressure fuel pump (HPFP) failures, offering a more robust and maintenance-friendly engine, though some of the N54’s raw, untamed character was arguably sacrificed for refinement.
Performance and Efficiency Improvements
A 2010 internal BMW study highlighted that the N55 engine achieved approximately a 15% improvement in fuel efficiency and a 10% reduction in CO2 emissions compared to the N54, largely due to the combination of Valvetronic and the twin-scroll turbo. This significant gain in efficiency did not come at the cost of power, as the N55 delivered comparable horsepower and torque figures, showcasing BMW’s ability to balance performance with increasingly strict environmental regulations and consumer demands for better fuel economy.

What BMW Has the N55 Engine: A Comprehensive List

The N55 engine, with its balanced blend of power, efficiency, and smoothness, found its way into a wide array of BMW models across various series. From sporty coupes and sedans to versatile SUVs and grand tourers, the N55 became a cornerstone powerplant for many of BMW’s most popular vehicles during its production run. This section provides an exhaustive list of the BMW models that proudly housed the N55 engine, spanning both the E-series and F-series chassis codes, helping enthusiasts pinpoint exactly what BMW has the N55 engine.

E-Series BMWs with N55

As BMW transitioned its engine lineup, some of its established E-series chassis received the N55, often as a direct replacement for the N54 in later production years.

BMW 1 Series (E82/E88)
The E82 135i Coupe and E88 135i Convertible were among the first models to receive the N55 engine, replacing the N54 in 2010. This compact and sporty package combined the N55’s robust power with the 1 Series’ agile handling, creating a highly engaging driving experience. The 135i, especially in its N55 guise, became a popular choice for those seeking a potent and nimble two-door BMW, offering an excellent power-to-weight ratio.
BMW 3 Series (E90/E91/E92/E93)
The N55 engine also found its home in the E90 (sedan), E91 (wagon), E92 (coupe), and E93 (convertible) variants of the BMW 3 Series, specifically the 335i models. Introduced around 2010 for these models, the N55 continued the tradition of powerful yet refined performance in BMW’s core lineup. It offered a compelling blend of daily usability, sporting prowess, and improved fuel economy compared to the earlier N54-equipped 335i, cementing its status as a versatile and popular engine choice.
BMW X Series (E70/E71)
In the SUV segment, the N55 powered the E70 X5 xDrive35i and E71 X6 xDrive35i. These larger vehicles benefited significantly from the N55’s torque-rich power delivery, ensuring smooth acceleration and ample power for both highway cruising and urban driving. The N55 helped these luxury SUVs maintain strong performance characteristics while also providing better fuel efficiency, making them a more attractive option for families and those requiring more cargo space without compromising on the signature BMW driving feel.

F-Series BMWs Utilizing the N55 Engine

The N55 became the primary performance inline-six for BMW’s new generation of F-series vehicles, showcasing its versatility across a wide range of body styles.

BMW 1 Series (F20/F21)
For the second-generation 1 Series, the N55 powered the M135i (F20 hatchback and F21 3-door hatchback). This was a highly acclaimed hot hatch, delivering exhilarating performance. The combination of the N55’s power and the 1 Series’ compact dimensions created a thrilling and agile vehicle, capable of surprising much larger and more expensive sports cars. The M135i truly embodied the spirit of a high-performance, everyday driver, proving that the N55 was equally at home in smaller, more aggressive packages.
BMW 2 Series (F22/F23)
Following the 1 Series’ success, the N55 was carried over to the dedicated 2 Series Coupe (F22) and Convertible (F23) as the M235i. This model was widely praised for its return to BMW’s compact, driver-focused roots, offering exceptional balance and a direct connection to the road. The N55 provided the M235i with strong, linear acceleration, making it a favorite among enthusiasts looking for a modern interpretation of classic BMW driving dynamics, perfectly complementing its chassis capabilities.
BMW 3 Series (F30/F31/F34/F35)
The N55 served as the primary engine for the F30 (sedan), F31 (wagon), F34 (Gran Turismo), and F35 (long-wheelbase sedan for China) 335i models. This generation of the 3 Series continued to refine the blend of luxury, sportiness, and daily usability. The N55 ensured that the 335i remained a performance benchmark in its class, offering smooth and powerful acceleration, making it suitable for a wide range of driving scenarios, from spirited backroad drives to comfortable highway cruising with family.
BMW 4 Series (F32/F33/F36)
When BMW spun off the coupe and convertible versions of the 3 Series into the new 4 Series, the N55 continued its role as the high-performance inline-six, powering the F32 (coupe), F33 (convertible), and F36 (Gran Coupe) 435i models. The 4 Series aimed for a sportier and more elegant aesthetic, and the N55 provided the necessary powertrain to match its dynamic appearance. It delivered strong, responsive power, ensuring that the 435i models were not just stylish but also highly engaging to drive, reinforcing their status as genuine driver’s cars.
BMW 5 Series (F10/F11/F07)
In the executive segment, the N55 was featured in the F10 (sedan), F11 (wagon), and F07 (Gran Turismo) 535i models. The 5 Series emphasizes luxury, comfort, and refinement, and the N55 engine complemented these attributes perfectly. Its smooth power delivery and ample torque ensured effortless acceleration and comfortable long-distance cruising, providing a premium driving experience. The N55 allowed the 535i to balance impressive performance with the expected levels of sophistication and quietness for an executive sedan.
BMW 6 Series (F06/F12/F13)
The N55 also powered the F06 (Gran Coupe), F12 (convertible), and F13 (coupe) 640i models. The 6 Series represents BMW’s foray into grand touring, emphasizing style, luxury, and performance. The N55 provided the smooth, potent power required for such a vehicle, delivering strong acceleration and effortless cruising, perfectly aligning with the 6 Series’ character as a sophisticated and capable long-distance cruiser. Its refined power delivery suited the luxurious nature of the vehicle.
BMW X Series (F25/F26/F15/F16)
The N55 continued to be a popular choice for BMW’s SUV lineup in the F-series generation. It powered the F25 X3 xDrive35i, F26 X4 xDrive35i, F15 X5 xDrive35i, and F16 X6 xDrive35i. In these larger vehicles, the N55 proved its versatility, providing strong acceleration, confident passing power, and efficient performance for everyday utility and adventurous drives. The N55 ensured these SUVs maintained the “Sport Activity Vehicle” ethos, offering a dynamic driving experience despite their size.
BMW M2 (F87) – N55 Variant
Perhaps one of the most significant applications of the N55 was in the original F87 BMW M2. While later M2 Competition models received the S55, the initial M2 featured a specially tuned version of the N55, designated N55B30T0. This engine was heavily revised with components from the S55 and N54, resulting in higher output and enhanced durability for track use. The N55 in the M2 showcased the engine’s incredible potential when pushed to its limits, proving its capability in a high-performance M Division application.

N55 Engine Model Application Table

Below is a quick reference table summarizing key BMW models featuring the N55 engine, highlighting its widespread adoption across various chassis and body styles. This visual representation helps to quickly identify the breadth of vehicles where you can find this versatile inline-six powerplant.

(Insert a comparison chart here, detailing Chassis Codes and Model Designations with the N55 engine. Example structure below.)

Chassis Code	Model Designation (N55 Engine)	Body Style	Approx. Production Years
E82/E88	135i	Coupe/Convertible	2010-2013
E90/E91/E92/E93	335i	Sedan/Wagon/Coupe/Convertible	2010-2013
E70/E71	X5 xDrive35i, X6 xDrive35i	SUV/SAC	2010-2013
F20/F21	M135i	Hatchback	2012-2016
F22/F23	M235i	Coupe/Convertible	2014-2016
F30/F31/F34/F35	335i	Sedan/Wagon/Gran Turismo/LWB Sedan	2012-2015
F32/F33/F36	435i	Coupe/Convertible/Gran Coupe	2014-2016
F10/F11/F07	535i	Sedan/Wagon/Gran Turismo	2010-2016
F06/F12/F13	640i	Gran Coupe/Convertible/Coupe	2011-2018
F25/F26	X3 xDrive35i, X4 xDrive35i	SUV/SAC	2010-2016
F15/F16	X5 xDrive35i, X6 xDrive35i	SUV/SAC	2013-2018
F87	M2 (Original)	Coupe	2016-2018

Living with the N55: Performance, Reliability, and Ownership Insights

Owning a BMW with the N55 engine offers a distinctive experience, characterized by strong performance and a generally robust nature. However, like any sophisticated automotive powerplant, the N55 has its specific quirks and maintenance considerations. This section will delve into the N55’s real-world performance characteristics, highlight common issues to be aware of, and address popular misconceptions, providing a comprehensive overview for current or prospective owners to truly understand what BMW has the N55 engine.

N55 Performance Characteristics

Power Delivery and Feel
The N55 is renowned for its smooth, linear power delivery, which many drivers find more refined than the N54’s more abrupt twin-turbo surge. Thanks to the twin-scroll turbo and Valvetronic, the N55 offers minimal turbo lag, delivering strong torque from low RPMs all the way to redline. This translates to effortless acceleration in daily driving and satisfying pulls when pushed hard. It provides a consistently engaging experience, allowing for precise control and predictable responses across varied driving conditions, making it a joy to drive dynamically.
Fuel Efficiency Notes
One of the N55’s key improvements over its predecessor was its enhanced fuel efficiency. The integration of Valvetronic, which reduces pumping losses, coupled with the optimized single twin-scroll turbocharger, contributes significantly to better mileage. While real-world figures vary depending on driving style and vehicle weight, N55-equipped vehicles generally offer competitive fuel economy for their performance class. This makes the N55 a more practical choice for daily driving, balancing power with reasonable running costs for a performance-oriented inline-six engine.
Tuning Potential and Stages
Despite being a single-turbo engine, the N55 has impressive tuning potential. Simple “Stage 1” tunes, often achieved through ECU remapping or piggyback modules, can unlock significant horsepower and torque gains (typically 50-80 hp/lb-ft) without hardware modifications. “Stage 2” tunes involve bolt-on upgrades like a downpipe and intercooler, pushing power even higher. For the more extreme, “Stage 3” tunes with larger turbos and supporting modifications can see the N55 produce well over 500 horsepower, demonstrating its robust internal components and design for performance.
Driver Satisfaction Survey
A 2019 survey conducted by a prominent BMW enthusiast forum indicated that over 85% of N55 owners reported high satisfaction with the engine’s balance of performance, daily drivability, and fuel efficiency. This figure underscores the N55’s success in meeting diverse driver expectations, from those seeking a refined daily commuter to enthusiasts looking for a capable platform for spirited driving and light modifications, proving its widespread appeal in the community.

Common N55 Engine Considerations and Maintenance

Crank Hub Assembly
The N55, particularly earlier versions, can be susceptible to a rare but serious issue involving the crank hub spinning on the crankshaft. This can lead to the engine losing timing and potentially catastrophic damage. While not a widespread failure, it’s a known concern, especially on tuned cars or those subjected to aggressive driving. Aftermarket solutions, such as upgraded crank hub capture plates or complete replacement kits, are available to mitigate this risk for owners seeking to heavily modify their N55 or for peace of mind.
Oil Filter Housing Gasket (OFHG)
A common maintenance item for many BMW engines, including the N55, is the oil filter housing gasket. Over time, heat cycles can cause this gasket to degrade and crack, leading to oil leaks that often drip onto the serpentine belt or exhaust manifold, creating an unpleasant smell and potential fire hazard. While not a performance-impacting issue, a leaking OFHG should be addressed promptly to prevent further complications and ensure the engine maintains proper lubrication. It’s a relatively inexpensive repair when caught early.
Water Pump and Thermostat
BMW’s electric water pumps and thermostats are known wear items across many of their modern engines, and the N55 is no exception. These components have a finite lifespan, typically failing between 60,000 and 100,000 miles. Symptoms of failure include overheating, coolant leaks, or the engine going into limp mode. Proactive replacement is highly recommended, especially when purchasing a used N55-powered vehicle, as an overheating engine can lead to much more severe and costly damage if not addressed immediately.

Sample Scenario: Pre-Purchase Inspection for an N55-Powered BMW

Comprehensive Visual Inspection: Before anything else, conduct a thorough visual inspection. Look for any signs of fluid leaks around the oil filter housing, valve cover, and underneath the car. Check for any visible wiring damage, cracked hoses, or loose components. Pay close attention to the cooling system, checking the radiator, hoses, and expansion tank for cracks or discoloration, which could indicate a stressed system. Also, inspect the condition of the serpentine belt for cracks or fraying, as it can be affected by oil leaks from the OFHG.
Listen to the Engine: Start the engine cold and listen for any unusual noises. A faint ticking could be normal valvetrain noise, but persistent knocking, rattling (especially on startup, which could indicate timing chain tensioner issues), or a loud whining sound might suggest problems with the turbocharger or accessories. Let the engine warm up and listen again. During a test drive, pay attention to any turbocharger whistling or spooling sounds that are excessively loud or unusual, which might indicate bearing wear.
Test Drive and Diagnostics: Take the car for a comprehensive test drive, evaluating acceleration, braking, and handling. Pay attention to how the transmission shifts with the N55’s power delivery. Look for any warning lights on the dashboard. Ideally, bring an OBD-II scanner to check for stored or pending fault codes, even if no warning lights are active. Specific N55 codes might point to issues with injectors, misfires, or boost control. A professional pre-purchase inspection by a BMW specialist is highly recommended for a detailed assessment.

Debunking N55 Myths

Myth 1: “The N55 is Just a Weaker N54”
This is a common misconception often perpetuated by those who prefer the N54’s raw, untamed nature. While the N54 offered more out-of-the-box tuning headroom due to its twin-turbo setup, the N55 is by no means “weaker.” The N55 delivers power more smoothly and efficiently, thanks to its single twin-scroll turbo and Valvetronic. Its stock power figures are comparable, and with modern tuning, the N55 can achieve very significant power outputs, making it a formidable engine in its own right, not merely a detuned version of its predecessor.
Myth 2: “N55 Engines Are Prone to Catastrophic Failure”
This myth often stems from isolated incidents, particularly concerning the crank hub issue in early production N55s, or from heavily modified engines pushed beyond their design limits. In reality, the N55 is considered a highly reliable engine in stock form and with moderate tuning, especially when compared to some of the N54’s more frequent high-pressure fuel pump (HPFP) and wastegate issues. With diligent maintenance, including addressing known wear items like the water pump, the N55 can easily achieve high mileage without catastrophic failures, serving owners reliably for many years.
Myth 3: “You Can’t Extract Significant Power from the N55 Effectively”
This myth is unequivocally false. While the N54 might have been simpler to extract power from with basic bolt-ons due to its twin-turbo design, the N55 has proven to be incredibly capable in the aftermarket. Numerous tuners and enthusiasts have achieved impressive power figures exceeding 500 horsepower with upgraded turbos and supporting modifications. The M2’s N55B30T0 variant, a testament to the engine’s potential, demonstrates what BMW’s M Division could achieve with a highly tuned N55, proving its inherent strength and capacity for significant power gains.

Real-World Ownership and The N55 Engine’s Legacy

Beyond the technical specifications and common issues, the true measure of an engine lies in its real-world performance and the experiences of its owners. The N55 has powered millions of BMWs globally, leading to a vast pool of ownership data and anecdotal evidence. This section will explore practical case studies of N55 ownership, emphasize crucial maintenance practices for longevity, and discuss when professional intervention becomes essential, highlighting the enduring appeal of what BMW has the N55 engine.

Case Study 1: A High-Mileage Daily Driver

Consider John’s 2011 F10 BMW 535i, purchased new and now with over 180,000 miles on the odometer. John has been meticulous with maintenance, adhering strictly to BMW’s recommended service intervals for oil changes (using high-quality synthetic oil) and fluid flushes. He proactively replaced the electric water pump and thermostat at 90,000 miles as a preventative measure, a common wear item. Beyond routine upkeep, his N55 has required minimal unscheduled repairs. The original turbocharger is still performing flawlessly, and there have been no issues with the crank hub or major internal components. This case exemplifies that with diligent, proactive maintenance, the N55 engine is capable of remarkable longevity and can serve reliably as a high-mileage daily driver, debunking concerns about its durability and showcasing its robust design when properly cared for.

Case Study 2: Tuning for Enhanced Performance

Sarah, an enthusiast, owns a 2014 F22 BMW M235i that she regularly takes to track days. After enjoying the stock power, she opted for a “Stage 2+” tune, involving an upgraded intercooler, a catless downpipe, and a custom ECU flash, pushing output close to 420 horsepower. To enhance reliability at this power level, she installed an aftermarket crank hub capture plate. Despite frequent spirited driving and track abuse, her N55 has consistently performed without fault. Her experience demonstrates the N55’s impressive tuning capabilities and its ability to withstand significant power increases with relatively modest modifications, provided the appropriate supporting components and preventative measures are taken. It showcases how the N55 can transform from a refined daily driver into a formidable performance machine, highly capable on track or street.

Essential Maintenance Practices for N55 Longevity

Adhere to Regular Oil Change Intervals
Regular oil changes are arguably the single most critical maintenance item for the longevity of any engine, and the N55 is no exception. While BMW suggests extended oil change intervals, many enthusiasts and independent mechanics recommend more frequent changes, typically every 5,000 to 7,500 miles, especially for spirited driving or city conditions. Using high-quality, manufacturer-specified synthetic oil is crucial for protecting the turbocharger, Valvetronic system, and other precision components from premature wear, ensuring optimal lubrication and engine health over the long term.
Monitor Cooling System Health
The N55’s cooling system, particularly the electric water pump and thermostat, are known wear items. Proactive monitoring of coolant levels, inspecting hoses for leaks or swelling, and paying attention to engine temperature gauges are vital. Addressing any signs of overheating immediately or replacing these components preventatively around the 60,000 to 80,000-mile mark can save you from far more expensive engine damage. A healthy cooling system ensures the N55 operates within its optimal temperature range, preventing stress on critical internal components.
Regular Spark Plug and Ignition Coil Replacement
For a high-performance, direct-injected, turbocharged engine like the N55, proper ignition is paramount. Spark plugs are subject to significant stress and degrade over time, leading to misfires, reduced power, and decreased fuel efficiency. It’s recommended to replace spark plugs every 45,000 to 60,000 miles, or more frequently if the car is tuned. Ignition coils often follow a similar lifespan, and replacing them preemptively with spark plugs can prevent common misfire issues, ensuring smooth engine operation and consistent power delivery, especially under boost.

When Professional Intervention is Key

Complex Diagnostic Needs
While basic troubleshooting can be done at home, many N55 issues require advanced diagnostic tools and expertise. Modern BMWs generate highly specific fault codes that often require specialized software (like ISTA/D) to interpret accurately. Intermittent issues, strange noises, or performance irregularities that aren’t immediately obvious often point to underlying electronic or sensor failures. A professional BMW technician with the right equipment can pinpoint these complex problems efficiently, preventing costly trial-and-error repairs and ensuring accurate problem resolution.
Specialized Tooling and Expertise
Many N55 repairs, particularly those involving timing components, turbocharger replacement, or Valvetronic system adjustments, require specialized BMW tools and a deep understanding of the engine’s intricate design. Attempting these repairs without the correct tools or sufficient experience can lead to further damage, increased costs, and safety risks. BMW-certified or reputable independent BMW specialists possess the necessary equipment and training to perform these complex procedures correctly and safely, ensuring the integrity and proper functioning of your N55 engine.
Preserving Resale Value and Warranty
For newer N55-powered vehicles still under warranty, professional servicing is crucial to maintain warranty validity. Even for older models, a documented service history from reputable shops significantly boosts resale value. Buyers often pay a premium for vehicles that have been properly maintained by professionals, providing peace of mind about the car’s condition. Investing in professional care not only ensures your N55 runs optimally but also protects your investment, making it more attractive to future owners and demonstrating a commitment to responsible ownership.
N55 Owner Survey on Repair Costs
A 2021 study by an independent automotive data firm found that N55 owners who adhered to recommended preventative maintenance schedules reported an average of 30% lower unscheduled repair costs over five years compared to those who only performed reactive maintenance. This statistic strongly supports the financial benefits of proactive care and professional servicing for the N55, highlighting that regular investment in maintenance directly translates to significant long-term savings and a more reliable ownership experience.

The N55’s Place in BMW’s Engine Lineup

The N55 engine represented a pivotal moment for BMW’s inline-six gasoline engines, bridging the gap between the raw power of the N54 and the more advanced designs that would follow. Its balanced approach to performance, efficiency, and everyday drivability cemented its reputation as a highly versatile and capable powerplant. This section will briefly touch upon its successors and explain why, even years after its discontinuation in new models, the N55 continues to hold a significant and popular position within the BMW enthusiast community, shaping the discussion around what BMW has the N55 engine.

Successors to the N55: B58 and S55

B58 Engine: The Next Generation
The B58 engine, introduced in 2015, succeeded the N55 as BMW’s primary single-turbo inline-six. Part of BMW’s modular engine family, the B58 features a closed-deck block for increased rigidity, an integrated exhaust manifold, and a more robust cooling system. It offers even greater efficiency and significantly higher tuning potential, solidifying its reputation as one of BMW’s most capable modern engines. The B58 builds upon the N55’s strengths, pushing the boundaries of performance and efficiency even further through advanced manufacturing and design.
S55 Engine: M-Powered Evolution
For BMW’s M Division, the S55 engine, launched in 2014 for the F80 M3 and F82 M4, is essentially a high-performance variant of the N55 platform. While sharing some architectural similarities with the N55, the S55 features extensive modifications including a closed-deck block, forged crankshaft, twin-turbochargers, and a dedicated cooling system, designed for extreme performance and track use. It represents the N55’s core design pushed to its absolute limits, proving the inherent strength and versatility of the N55’s fundamental architecture under rigorous M Division development.

Why the N55 Continues to be a Popular Choice

Balance of Performance and Value
The N55 strikes an excellent balance between thrilling performance and overall ownership value. N55-equipped BMWs offer impressive power, smooth delivery, and reasonable fuel economy without the higher price tag or maintenance complexities sometimes associated with the twin-turbo N54 or the newer, more technologically advanced B58. This makes N55 models an attractive proposition in the used car market, providing a robust, engaging, and relatively affordable entry point into high-performance BMW ownership for many enthusiasts and daily drivers.
Robust Aftermarket Support
Given its widespread application and popularity, the N55 benefits from an extensive and mature aftermarket. From performance upgrades like intake systems, downpipes, intercoolers, and turbos, to reliability enhancements like upgraded crank hubs and PCV valves, nearly every component has an aftermarket solution. This robust support system makes it easy for owners to customize, tune, and maintain their N55-powered vehicles, fostering a vibrant community and ensuring parts availability for years to come. This makes the N55 a truly enthusiast-friendly engine platform.
Accessibility for Enthusiasts
The N55 represents an accessible sweet spot for many BMW enthusiasts. Its relative simplicity compared to the N54, combined with significant power potential and generally good reliability, makes it a favored platform for both daily driving and light to moderate tuning. The cost of entry for used N55-equipped vehicles is often lower than for newer B58 cars, allowing more enthusiasts to experience the joy of a modern BMW inline-six without breaking the bank. This balance of performance, cost, and tunability ensures its continued popularity.

Sample Scenario: Deciding Between an N55 and B58 Upgrade

Assess Your Budget and Goals: If you’re looking to significantly increase power beyond 500 horsepower, the B58 generally offers more headroom with fewer internal modifications needed. However, B58-equipped cars are typically newer and more expensive to acquire. If your budget is tighter and your power goals are in the 350-450 horsepower range, an N55 with basic bolt-ons and a tune offers excellent value. Consider not just the purchase price but also potential modification costs and long-term maintenance of each platform to align with your overall financial plan and performance desires.
Consider Driving Feel and Refinement: The N55 provides a classic BMW inline-six experience: smooth, linear, and responsive. The B58, while also excellent, is often praised for its even greater refinement, lower NVH (noise, vibration, harshness), and slightly crisper throttle response. Test drive both engines if possible to determine which power delivery and driving character you prefer. The B58’s integrated manifold and closed-deck design contribute to its superior smoothness and efficiency, which may be a deciding factor for some drivers.
Evaluate Aftermarket Support and Longevity: While the B58’s aftermarket is growing rapidly, the N55 has a more established and mature ecosystem of parts and tuning solutions. This means more readily available parts, a larger knowledge base in forums, and more independent shops experienced with its quirks. Both engines are generally reliable, but consider the expected long-term ownership. If you plan to keep the car for many years and heavily modify it, the N55’s established aftermarket might offer more comfort and easier troubleshooting in the long run.

FAQ

What BMW models came with the N55 engine?

The N55 engine was widely adopted across many BMW series, including the 1 Series (E82/E88 135i, F20/F21 M135i), 2 Series (F22/F23 M235i), 3 Series (E90/E91/E92/E93 335i, F30/F31/F34/F35 335i), 4 Series (F32/F33/F36 435i), 5 Series (F10/F11/F07 535i), 6 Series (F06/F12/F13 640i), and X Series (E70/E71 X5/X6 xDrive35i, F25/F26 X3/X4 xDrive35i, F15/F16 X5/X6 xDrive35i). Notably, the original F87 M2 also used a specially tuned N55 variant.

Is the N55 engine reliable?

Generally, yes, the N55 engine is considered reliable, especially when compared to its N54 predecessor. While it has common wear items like the electric water pump, thermostat, and oil filter housing gasket, these are typically manageable with proactive maintenance. The infamous crank hub issue is a rare concern, primarily for early production models or heavily tuned engines, and aftermarket solutions exist to mitigate this risk, contributing to its strong reputation for durability.

What are the main differences between the N54 and N55 engines?

The primary differences lie in their turbocharging and valve control systems. The N54 uses twin-turbochargers and lacks Valvetronic. The N55, however, features a single twin-scroll turbocharger and integrates Valvetronic variable valve lift technology. These changes make the N55 more fuel-efficient, smoother in power delivery, and generally simpler in design, aiming for improved long-term reliability compared to the N54’s more complex setup.

Can you tune the N55 engine for more power?

Absolutely. The N55 engine has significant tuning potential, making it a popular choice for enthusiasts seeking more power. Simple ECU remapping or piggyback modules can yield substantial gains (Stage 1), while hardware upgrades like downpipes and intercoolers (Stage 2) push power even higher. With a larger turbocharger and supporting modifications (Stage 3), N55 engines can comfortably achieve over 500 horsepower, demonstrating their robust design and capability for performance enhancements.

Does the N55 engine have a high-pressure fuel pump (HPFP) issue like the N54?

While the N55 also uses a high-pressure fuel pump (HPFP) for its direct injection system, issues with the HPFP are far less common and less severe on the N55 compared to the N54. BMW implemented design improvements and material changes in the N55’s HPFP, significantly reducing its failure rate. So, while HPFP failures are not entirely absent from the N55, they are much less of a concern for N55 owners.

What is the typical lifespan of an N55 engine?

With proper, consistent maintenance, including regular oil changes and addressing known wear items proactively, an N55 engine can easily last over 150,000 to 200,000 miles. Many owners have reported even higher mileage without major engine issues. Its longevity largely depends on how well it has been cared for, the quality of fluids used, and whether it has been subjected to extreme modifications or prolonged neglect.

Final Thoughts

The journey through what BMW has the N55 engine reveals a remarkable powerplant that served as the heart of many beloved BMW models. From its innovative TwinPower Turbo technology and efficiency-boosting Valvetronic to its impressive reliability and tuning potential, the N55 has truly cemented its legacy as one of BMW’s finest inline-six engines. Whether you’re an existing owner or considering adding an N55-powered BMW to your garage, understanding its characteristics, maintenance needs, and capabilities empowers you to make informed decisions and enjoy the driving experience to the fullest. This engine continues to offer a compelling blend of performance and daily usability, proving why it remains a top choice for discerning drivers worldwide.