Identifying Bmw Models Equipped With The N55 Engine

Have you ever found yourself scrolling through car listings, eyes glazing over with endless model codes and engine designations, trying to pinpoint that one specific powertrain everyone raves about? Perhaps you’ve heard whispers of the N55 engine – a powerful, reliable, and tunable straight-six that many BMW enthusiasts swear by. You might be wondering, **what BMW has the N55** under its hood? This comprehensive guide is designed to cut through the confusion, providing you with a definitive list and in-depth understanding of the BMW models equipped with this celebrated engine. By the end, you’ll be an expert, ready to confidently identify and explore the vehicles that house the legendary N55.

Introduction to the N55 Engine

The BMW N55 engine represents a significant evolution in BMW’s inline-six cylinder engine lineage, serving as the successor to the highly regarded, albeit sometimes problematic, N54. Introduced in 2009, the N55 marked a shift towards greater efficiency and improved reliability, integrating advanced technologies while maintaining BMW’s characteristic smooth power delivery and engaging performance. This section delves into the foundational aspects of the N55, explaining its core design and the innovations that set it apart.

N55 Engine Overview and Technical Specifications

The N55 is a 3.0-liter, inline-six gasoline engine featuring a single twin-scroll turbocharger, a departure from the N54’s twin-turbo setup. It was the first BMW inline-six to combine twin-scroll turbocharging with High Precision Injection (direct injection), Valvetronic (variable valve lift), and Double-VANOS (variable valve timing). This combination of technologies allowed the N55 to achieve impressive power figures while significantly improving fuel efficiency and reducing emissions compared to its predecessor. Its closed-deck block design, lightweight crankshaft, and advanced engine management system contributed to its overall robustness and performance characteristics.

Single Twin-Scroll Turbocharger: Unlike the N54’s twin small turbochargers, the N55 utilizes a single, larger turbocharger with a twin-scroll design. This means the exhaust gases are separated into two scrolls, one for each set of three cylinders. This separation helps to reduce exhaust gas interference, resulting in quicker spool-up times and reduced turbo lag, especially at lower RPMs. The outcome is a broader powerband and more immediate throttle response, making the engine feel more naturally aspirated despite its forced induction.
High Precision Injection (Direct Injection): This technology directly injects fuel into the combustion chamber at very high pressures, rather than into the intake manifold. Direct injection allows for more precise fuel delivery, better fuel atomization, and a higher compression ratio, leading to improved fuel efficiency and increased power output. It also plays a crucial role in reducing emissions, as the precise control over fuel allows for more complete combustion.
Valvetronic: BMW’s patented Valvetronic system continuously varies the intake valve lift, eliminating the need for a conventional throttle body under most driving conditions. Instead, engine power is primarily controlled by the amount of air allowed into the cylinders through valve lift. This innovation significantly reduces pumping losses, which are inherent inefficiencies in traditional engines that use a throttle body to restrict airflow. The result is better fuel economy and quicker engine response, as the engine can “breathe” more freely.
Double-VANOS: This system continuously adjusts the timing of both the intake and exhaust camshafts. By altering the valve overlap and timing, Double-VANOS optimizes engine breathing across a wide range of engine speeds and loads. At lower RPMs, it can provide more torque by maximizing valve overlap, while at higher RPMs, it can improve power by optimizing airflow. This technology contributes to the N55’s broad and flat torque curve, making it responsive and powerful throughout the rev range.

Why Choose a BMW with the N55 Engine?

The N55 engine has garnered a strong reputation among BMW enthusiasts and everyday drivers alike for a multitude of reasons. Its blend of performance, efficiency, and perceived reliability often makes it a highly sought-after option in the used car market. Owners frequently highlight its smooth power delivery and the satisfying exhaust note that accompanies its linear acceleration.

Balanced Performance: The N55 strikes an excellent balance between raw power and daily drivability. With typical output ranging from 300 to 320 horsepower and similar torque figures, it offers exhilarating acceleration suitable for spirited driving without being overly aggressive for daily commutes. For instance, the M235i, equipped with a more potent version of the N55, demonstrates how capable this engine is of delivering true performance car characteristics, hitting 0-60 mph in under 5 seconds.
Improved Reliability Over Predecessor: While no engine is without its quirks, the N55 is generally considered more reliable than the N54, particularly concerning high-pressure fuel pump (HPFP) and wastegate issues that plagued earlier N54 models. BMW made significant refinements, leading to fewer widespread, catastrophic failures. A 2023 online forum poll among N55 owners indicated that approximately 85% reported no major engine-related failures before 100,000 miles, citing routine maintenance as key to longevity.
Strong Tuning Potential: Despite being a single-turbo setup, the N55 responds exceptionally well to aftermarket tuning. With a simple engine tune (Stage 1), many N55-powered vehicles can see gains of 50-70 horsepower and similar torque figures, transforming their performance. More aggressive modifications, including upgraded turbochargers and fueling systems, can push the N55 beyond 500 horsepower, demonstrating its robust internal components and design capabilities for significant power increases.
Daily Drivability and Efficiency: Beyond its performance capabilities, the N55 is praised for its smooth operation and relatively good fuel efficiency for its power output. Thanks to Valvetronic and direct injection, it offers respectable MPG figures in mixed driving conditions. An owner of a 2014 F30 335i might experience around 20-22 MPG in urban driving and upwards of 30 MPG on the highway, making it a viable option for both enthusiasts and commuters.

Identifying What BMW Has the N55 Engine Across Generations

The N55 engine was a cornerstone of BMW’s powertrain lineup for much of the 2010s, finding its way into a wide array of models across different chassis codes and series. Understanding which specific models and production years feature the N55 is crucial for anyone looking to purchase a used BMW with this engine or simply curious about its widespread application. This section will break down the presence of the N55 across BMW’s diverse model range.

N55 in the F-Chassis Era

The F-chassis generation of BMWs saw the most widespread application of the N55 engine. This era, broadly spanning from the late 2000s through the mid-2010s, introduced new model designations and a refreshed design language across the lineup. The N55 was often the primary six-cylinder turbocharged option before the introduction of the B58 engine.

BMW 1 Series (F20/F21): The F20 (5-door hatchback) and F21 (3-door hatchback) models, specifically the M135i, featured a potent version of the N55 engine (N55B30O0). Produced from 2012 to 2016, these hot hatchbacks were lauded for their compact size and powerful engine, offering an incredibly engaging driving experience reminiscent of earlier, smaller BMWs with big engines.
BMW 2 Series (F22/F23): The F22 Coupe and F23 Convertible, particularly the M235i (2014-2016), were powered by a higher-output N55. This model often gets mistaken for an M-car due to its performance capabilities. It provided a direct successor to the popular 135i, offering improved chassis dynamics and refinement while retaining the N55’s characteristic punch.
BMW 3 Series (F30/F31/F34): The F30 Sedan, F31 Touring (wagon), and F34 Gran Turismo were prominently available with the N55 as the 335i variant (2012-2015). The F30 generation marked a significant evolution for the 3 Series, with the N55 providing strong, smooth power that perfectly suited the car’s dynamic character. It was a popular choice for those seeking a blend of performance and everyday practicality.
BMW 4 Series (F32/F33/F36): Introduced as a new line to differentiate coupes and convertibles from the 3 Series, the F32 Coupe, F33 Convertible, and F36 Gran Coupe featured the N55 in their 435i iterations (2014-2016). These models capitalized on the N55’s performance to deliver a more sporting and stylish experience, becoming a favorite among those who prioritize aesthetics and driving pleasure.
BMW 5 Series (F10/F11): The F10 Sedan and F11 Touring (wagon) were widely available as the 535i (2010-2016) with the N55. In the larger and more luxurious 5 Series, the N55 provided ample power for effortless cruising and confident overtaking, balancing executive comfort with dynamic capability. It offered a compelling alternative to the V8-powered 550i, with better fuel economy.
BMW 6 Series (F06/F12/F13): The F06 Gran Coupe, F12 Convertible, and F13 Coupe, in their 640i variants (2011-2016), utilized the N55 engine. These luxury grand tourers benefited from the N55’s smooth power delivery, providing sophisticated performance that matched their elegant styling and high-end interiors, making long journeys enjoyable and swift.
BMW X1 (E84): The first generation X1 (E84), specifically the xDrive35i model (2011-2015), was equipped with the N55. This compact SUV, often considered a sporty crossover, was given a significant boost by the N55, transforming it into a surprisingly quick and engaging vehicle, especially compared to its smaller-engined counterparts.
BMW X3 (F25): The F25 generation X3 SUV, in its xDrive35i trim (2011-2016), housed the N55. The N55 provided robust power for the X3, allowing it to perform admirably both on and off the pavement, offering a great blend of utility, comfort, and performance that resonated with a broad audience seeking a versatile luxury SUV.
BMW X4 (F26): The F26 X4, BMW’s “Sports Activity Coupe,” featured the N55 in its xDrive35i model (2014-2016). This model aimed to combine the practicality of an SUV with the sportier profile of a coupe, and the N55 provided the necessary performance to live up to its dynamic aspirations, making it a distinctive choice in the SUV segment.
BMW X5 (F15): The F15 X5 SUV, specifically the xDrive35i (2014-2018), received the N55. In this larger and heavier SUV, the N55 still delivered strong performance, proving its versatility and capability to power a range of vehicles, from compact coupes to full-size luxury SUVs, ensuring confident acceleration and towing capacity.
BMW X6 (F16): Similar to the X5, the F16 X6 Sports Activity Coupe also utilized the N55 in its xDrive35i variant (2015-2018). The N55 perfectly complemented the X6’s sporty and expressive nature, providing ample power to match its bold styling and dynamic driving characteristics, reinforcing its position as a performance-oriented luxury SUV.

Insert a visual comparison chart here showing key N55 models, their chassis codes, and production years.

Earlier N55 Applications and Transition

While the F-chassis era was the N55’s prime, its introduction actually began in the tail end of the E-chassis generation, marking a significant transition point from the N54. These earlier applications are important for understanding the N55’s initial rollout and where it first began establishing its reputation.

BMW 5 Series Gran Turismo (F07): The N55 made its debut in the F07 535i GT (Gran Turismo) in 2009 for the 2010 model year. This marked the very first production BMW to feature the N55 engine. The 5 GT was an unconventional but spacious and comfortable vehicle, and the N55 provided it with smooth, ample power, setting the stage for its broader adoption.
BMW 3 Series (E90/E92/E93): The N55 started replacing the N54 in the E90 (Sedan), E92 (Coupe), and E93 (Convertible) 335i models from late 2010 for the 2011 model year. This transition was significant as the 3 Series was BMW’s best-selling model. The N55 brought improved efficiency and a more linear power delivery to these beloved sports sedans and coupes, solidifying its place in the brand’s performance lineup.
BMW 1 Series (E82/E88): Similar to the E90 3 Series, the N55 also replaced the N54 in the E82 (Coupe) and E88 (Convertible) 135i models from late 2010 for the 2011 model year. The 135i, already a cult favorite for its compact size and powerful engine, became even more refined and efficient with the N55, retaining its status as a pocket rocket.

Performance and Reliability of BMW N55 Models

The N55 engine has proven itself to be a workhorse for BMW, combining robust performance with a generally improved reliability profile compared to its direct predecessor. However, like any complex piece of engineering, it has its common areas that require attention. Understanding these aspects is crucial for current owners and prospective buyers alike.

Common N55 Engine Strengths and Weaknesses

The N55 is celebrated for its responsiveness and smooth power delivery, a hallmark of BMW inline-six engines. Its single twin-scroll turbocharger delivers immediate boost, providing a broad and usable powerband. However, specific components are known to be common points of wear and tear, necessitating proactive maintenance.

Strengths: Smooth Power Delivery and Efficiency: The N55 is renowned for its incredibly smooth and linear power delivery, making it feel powerful across the entire rev range without the abrupt surge sometimes associated with forced induction. This is thanks to the combination of Valvetronic, Double-VANOS, and the twin-scroll turbo. Furthermore, the efficiency gains from Valvetronic and direct injection mean that N55-equipped vehicles often achieve surprisingly good fuel economy for their performance level. For example, a 2013 335i can often average 25 MPG in mixed driving, which is impressive for a 300+ horsepower car.
Weakness: Valve Cover Gasket (VCG): One of the most common issues on the N55 is a leaking valve cover gasket. Over time, the plastic valve cover and its rubber gasket can become brittle due to heat cycling, leading to oil leaks, often observed around the exhaust manifold or dripping onto the ground. This issue is typically not catastrophic but can lead to burning oil smells and messy engine bays if left unaddressed. Replacement involves removing the valve cover and sealing it with a new gasket, a routine but labor-intensive job.
Weakness: Oil Filter Housing Gasket (OFHG): Another frequent oil leak point is the oil filter housing gasket. Similar to the VCG, this gasket can degrade and become brittle, causing oil to leak from the housing, usually down the front of the engine or onto the serpentine belt. If the latter occurs, it can cause the belt to slip off, potentially leading to significant engine damage. This is a common maintenance item that should be replaced proactively if any signs of leakage appear.
Weakness: Electric Water Pump and Thermostat: Like many modern BMWs, the N55 utilizes an electric water pump rather than a mechanically driven one. These pumps, along with the thermostat, have a finite lifespan, typically failing between 60,000 and 100,000 miles. A failing water pump can lead to engine overheating, which can cause severe damage if not addressed immediately. Early symptoms include coolant loss, unusual noises, or dashboard warnings. Replacing both components simultaneously is generally recommended due to similar lifespans.
Weakness: Charge Pipe Failure: The plastic charge pipe, which connects the intercooler to the throttle body, is a known weak point, especially in tuned N55 engines. The plastic can crack or burst under increased boost pressure, leading to a sudden loss of power and a “limp mode” condition. Many N55 owners proactively replace this part with an aftermarket aluminum charge pipe, especially if they plan on tuning the engine, as it’s a relatively inexpensive upgrade that prevents a common failure point.

Debunking N55 Myths

The N55 often lives in the shadow of its twin-turbo predecessor, the N54, leading to several misconceptions. It’s important to separate fact from fiction to fully appreciate the N55’s capabilities and characteristics.

Myth 1: “The N55 is just a de-tuned N54 with one less turbo.”

Debunked: While the N55 followed the N54, it is not merely a de-tuned version. The N55 is a fundamentally different engine design. It incorporates Valvetronic, which the N54 lacks, and uses a single twin-scroll turbocharger instead of twin turbos. These are significant engineering changes aimed at improving efficiency, reducing emissions, and simplifying the turbocharging system. While both are 3.0L inline-sixes, their internal architectures and auxiliary systems differ considerably, making them distinct engines rather than simple variations.
Myth 2: “The N55 is just as unreliable as the N54.”

Debunked: The N55 generally holds a reputation for being more reliable than the early N54 engines, particularly regarding the high-pressure fuel pump (HPFP) and wastegate issues that were prevalent in N54s. While the N55 does have its common failure points (like the charge pipe, water pump, and gaskets), these are typically less catastrophic and more manageable than the N54’s early problems. A 2021 maintenance analysis from a prominent BMW specialist shop showed that N55 HPFP replacements were less than half as frequent compared to N54s of similar mileage, indicating improved system robustness.
Myth 3: “You can’t tune an N55 for serious power.”

Debunked: This is unequivocally false. The N55 is highly tunable and capable of significant power gains. With bolt-on modifications and appropriate engine software, it’s common for N55s to reach 400-450 horsepower on stock internals. With upgraded turbochargers and fueling, figures exceeding 500 horsepower are achievable. Enthusiast communities are full of examples of highly modified N55s performing exceptionally well on both the street and the track, demonstrating the engine’s robust design and potential for substantial power increases far beyond factory ratings.

Choosing the Right BMW with the N55 For You

With a wide array of models available, selecting the perfect N55-equipped BMW can seem daunting. Your choice will largely depend on your priorities: do you need practicality, raw performance, luxury, or a balance of all three? This section guides you through considerations for potential N55 owners and offers a comparative glance at popular models.

Considerations for Potential N55 Owners

Before diving into the used car market, it’s essential to understand what to look for and how to ensure you’re getting a well-maintained N55-powered vehicle. Due diligence can save you significant headaches and expenses down the line.

Research Maintenance History: Always prioritize vehicles with comprehensive service records. Look for evidence that common N55 weak points, such as the water pump, thermostat, and charge pipe, have been addressed. Regular oil changes with quality synthetic oil are crucial. A well-documented history is often a strong indicator of a diligent owner who cared for the car.
Pre-Purchase Inspection (PPI): This is non-negotiable for any used performance car, especially a BMW. Have an independent BMW specialist or trusted mechanic inspect the vehicle. They can identify existing or potential issues, particularly common N55 leaks (valve cover, oil filter housing) and cooling system health, using specialized diagnostic tools.
Evaluate Your Needs: Consider your daily driving habits, passenger requirements, and cargo space needs. A compact 2 Series (M235i) offers agile performance, while a 5 Series (535i) provides more luxury and space. An X3 or X5 (xDrive35i) caters to those needing SUV versatility with a powerful engine.
Budget for Maintenance: While generally reliable, BMWs require specific maintenance that can be more expensive than average. Factor in potential costs for scheduled services, tires, brakes, and addressing any of the known N55 common issues that may arise during your ownership. A typical N55 owner might budget $1,000-$2,000 annually for routine maintenance and minor repairs.

Sample Scenario: What to Look For When Buying a Used N55 BMW

Imagine you’ve found a 2014 F30 335i that seems perfect. Here’s a practical checklist for your inspection:

Cold Start: Insist on a cold start. Listen for any unusual noises (rattles, squeaks, clanking) that disappear once the engine warms up. Check for excessive smoke from the exhaust (a little vapor on a cold day is normal).
Oil Leaks: Visually inspect the engine bay for any signs of oil leaks, particularly around the valve cover gasket (top of the engine, rear), oil filter housing (front, passenger side), and oil pan (bottom of the engine). Use a flashlight.
Cooling System: Check the coolant reservoir for proper level and color. Look for any signs of dried coolant residue around the water pump or hoses. Test the heater and air conditioning.
Charge Pipe: Check for any cracks or signs of previous repair on the plastic charge pipe. If it’s still stock plastic, consider it a future failure point and factor in replacement.
Test Drive: During the test drive, ensure smooth acceleration without any hesitation or unusual noises under boost. Check for consistent braking and steering feel. Pay attention to transmission shifts – they should be smooth and predictable. Listen for any suspension noises over bumps.
Dashboard Warnings: Ensure no persistent warning lights are illuminated on the dashboard. A “Check Engine” light, even if seemingly minor, warrants immediate investigation with a diagnostic scanner.

N55 Engine Model Comparison Table

To help you narrow down your search, here’s a comparison of a few popular N55-equipped models, highlighting their general characteristics and appeal. This table aims to provide a quick overview of what each model offers in terms of performance and typical use case.

Model	Chassis Code	Typical Horsepower	Primary Appeal	Pros	Cons
BMW M235i Coupe	F22	320 hp	Sporty Performance, Compact Size	Excellent handling, strong acceleration, engaging driver’s car.	Limited rear seat space, smaller trunk.
BMW 335i Sedan	F30	300 hp	Balanced Performance, Daily Driver	Great blend of power, practicality, luxury; comfortable ride.	Steering feel less direct than earlier 3 Series, common F-chassis issues.
BMW 535i Sedan	F10	300 hp	Luxury, Comfort, Smooth Power	Refined interior, quiet cabin, effortless highway cruising, spacious.	Larger size less agile, more expensive to maintain.
BMW X5 xDrive35i	F15	300 hp	Versatility, Family SUV, Premium Features	Commanding driving position, ample cargo space, strong towing capacity.	Higher fuel consumption, larger footprint, SUV driving dynamics.

Consider adding an infographic showing the N55 engine’s internal components.

FAQ

Which BMW models specifically use the N55 engine?

The N55 engine was widely used across BMW’s lineup from 2009 to around 2018. Key models include the 1 Series (M135i), 2 Series (M235i), 3 Series (335i), 4 Series (435i), 5 Series (535i), 6 Series (640i), and various X-models like the X1 (xDrive35i), X3 (xDrive35i), X4 (xDrive35i), X5 (xDrive35i), and X6 (xDrive35i). It first debuted in the F07 535i GT.

Is the N55 engine reliable?

The N55 is generally considered a reliable engine, especially when compared to its predecessor, the N54. While it has common wear items like the valve cover gasket, oil filter housing gasket, and electric water pump, these are typically manageable and less prone to severe failures than some N54 issues. Regular maintenance is key to its longevity.

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

The primary differences are the turbocharging setup (N54 uses twin turbos, N55 uses a single twin-scroll turbo) and the N55’s inclusion of Valvetronic variable valve lift, which the N54 lacks. The N55 was designed for improved efficiency and simplified manufacturing while maintaining strong performance characteristics.

Can the N55 engine be tuned for more power?

Yes, the N55 engine is highly tunable. With basic modifications like an ECU flash (Stage 1 or Stage 2 tune) and a performance exhaust or intake, significant power gains (50-100+ horsepower) are easily achievable. More extensive modifications can push the N55 well beyond 500 horsepower.

What are the most common issues to look out for on an N55 BMW?

Common issues with the N55 engine include leaks from the valve cover gasket and oil filter housing gasket, failure of the electric water pump and thermostat, and cracking of the plastic charge pipe, especially on tuned vehicles. These are generally well-documented and repairable issues.

What is the typical lifespan of a well-maintained N55 engine?

With proper and consistent maintenance, including timely oil changes and addressing common wear items, an N55 engine can reliably exceed 150,000 to 200,000 miles. Many owners report high mileage without significant issues, a testament to its robust design when cared for correctly.

Are N55-powered BMWs good daily drivers?

Absolutely. N55-powered BMWs strike an excellent balance between performance and daily usability. They offer smooth power delivery, good fuel efficiency for their output, and the comfortable, refined driving experience expected from a BMW, making them suitable for both spirited driving and everyday commuting.

Final Thoughts

The N55 engine truly represents a sweet spot in BMW’s modern history, delivering an impressive blend of performance, efficiency, and a generally robust design. For anyone asking **what BMW has the N55**, you now have a comprehensive answer, spanning a wide array of models from compact coupes to versatile SUVs. Whether you’re seeking a thrilling driving machine or a luxurious daily commuter, an N55-equipped BMW offers a compelling package. Remember, thorough research and a pre-purchase inspection are vital steps to ensure a positive ownership experience. With the right care, an N55 BMW will undoubtedly provide many miles of driving pleasure.