Introduction

The BMW F22 2 Series quickly became one of the most beloved modern BMW platforms among driving enthusiasts. Introduced in 2014 as the successor to the 1 Series coupe, the F22 delivered something many fans felt BMW had been moving away from: a compact, rear-wheel-drive coupe with strong performance and engaging driving dynamics.

Within the lineup, two models stand out for performance-focused buyers: the BMW F22 M235i and the BMW M240i. Both cars occupy the same position in the range—sitting below the full M2—but they feature different engines, updated technology, and subtle improvements that make the comparison interesting.

The debate around M235i vs M240i typically centers on one key topic: N55 vs B58. The earlier M235i uses BMW’s well-known N55 turbocharged inline-six, while the later M240i introduced the newer and more advanced B58 engine.

In this BMW 2 Series performance comparison, we’ll break down the differences in performance, driving feel, reliability, and tuning potential to help you decide which of these performance coupes deserves a place in your garage.

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Overview of the BMW M235i

Engine: N55 Turbocharged Inline-Six

The BMW F22 M235i, introduced for the 2014 model year, was the first true performance variant of the new 2 Series coupe. Under the hood sits BMW’s N55 3.0-liter turbocharged inline-six, an engine already proven in several BMW performance models.

Key engine characteristics include:

   • 3.0L single turbo inline-six (N55)

   • Twin-scroll turbocharger

   • Direct fuel injection

   • Valvetronic variable valve lift

   • Double VANOS variable valve timing

This engine became well known for its smooth power delivery, strong mid-range torque, and tuning potential.

Performance Specs

Typical factory performance figures for the M235i include:

   • Horsepower: ~320 hp

   • Torque: ~330 lb-ft (450 Nm)

   • 0–60 mph: ~4.6 seconds (automatic)

   • Top speed: 155 mph (limited)

The car was available with either:

   • 6-speed manual transmission

   • 8-speed ZF automatic

Rear-wheel drive was standard, with xDrive AWD available in some markets.

Driving Characteristics

One of the most praised aspects of the M235i was its balanced driving experience.

Reviewers consistently noted that the car behaved like a “proper BMW,” combining:

   • Responsive steering

   • Well-balanced chassis

   • A comfortable but sporty suspension setup

   • Strong acceleration from the turbocharged six-cylinder engine

The suspension strikes a balance between performance and daily usability, offering responsive handling without excessive harshness. In normal driving, the cabin remains quiet and refined, but pressing the throttle unleashes the characteristic inline-six roar.

Selectable drive modes significantly change the car’s behavior, especially throttle response and transmission performance.

Why Enthusiasts Love the M235i

The BMW F22 M235i quickly became a favorite among enthusiasts for several reasons:

   • Classic BMW inline-six performance

   • Compact and relatively lightweight platform

   • Excellent rear-wheel-drive balance

   • Strong aftermarket support

   • Affordable entry point into modern BMW performance

For many drivers, the M235i captures the spirit of classic BMW coupes while still offering modern technology and comfort.

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Overview of the BMW M240i

Engine: B58 Turbocharged Inline-Six

In 2017, BMW updated the F22 lineup and introduced the BMW M240i, replacing the M235i. The most significant upgrade was the introduction of the B58 engine, BMW’s next-generation turbocharged inline-six.

The B58 represents a major step forward in BMW engine design.

Key features include:

   • 3.0L turbocharged inline-six (B58)

   • Closed-deck engine block

   • Integrated water-to-air intercooler

   • Improved thermal efficiency

   • Stronger internal components

Compared to the N55, the B58 is widely considered more powerful, more efficient, and more robust.

Performance Specs

Factory performance numbers for the M240i include:

   • Horsepower: ~335 hp

   • Torque: ~369 lb-ft (500 Nm)

   • 0–60 mph: ~4.3 seconds (automatic)

   • Top speed: 155 mph (limited)

Just like the M235i, the M240i was available with:

   • 6-speed manual

   • 8-speed automatic transmission

   • Rear-wheel drive or xDrive AWD

Improvements Over the M235i

The M240i isn’t a complete redesign of the car, but it includes several meaningful upgrades:

1. More Power and Torque

The B58 delivers noticeably more torque, especially in the mid-range.

2. Better Efficiency

Despite increased power, the newer engine is also more fuel-efficient.

3. Improved Cooling and Strength

The closed-deck design and improved cooling system make the B58 a stronger platform for high-performance tuning.

4. Updated Technology

Facelift models also brought updates to:

   • Infotainment systems

   • Interior materials

   • Lighting design

Driving Experience

On the road, the BMW M240i feels very similar to the M235i but with a few key improvements.

Drivers often notice:

   • Stronger mid-range acceleration

   • Smoother turbo response

   • Improved engine refinement

The chassis remains largely unchanged, meaning the M240i still offers the agile handling and compact feel that made the F22 platform so popular.

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Key Differences Between the M235i and M240i

Engine Technology: N55 vs B58

The biggest difference in the M235i vs M240i comparison is the engine.

N55 (M235i):

   • Single twin-scroll turbo

   • Open-deck block

   • Proven reliability

   • Strong tuning support

B58 (M240i):

   • Newer engine architecture

   • Closed-deck block

   • Integrated intercooler

   • Higher efficiency and durability

The B58 is generally considered the more advanced and future-proof engine.

Power and Torque

The M240i has a clear torque advantage, which makes the car feel stronger during everyday driving and acceleration.

Reliability and Tuning Potential

Both engines are respected in the BMW tuning community.

N55 reliability highlights:

   • Well understood by mechanics and tuners

   • Large aftermarket ecosystem

   • Proven long-term durability

B58 reliability highlights:

   • Stronger block design

   • Better cooling

   • Capable of handling more power

Many enthusiasts consider the B58 one of BMW’s best modern engines.

Driving Feel

The overall driving experience is similar, but there are subtle differences:

M235i:

   • Slightly more raw and mechanical

   • Classic turbocharged inline-six character

M240i:

   • Smoother power delivery

   • Stronger mid-range acceleration

   • Slightly more refined feel

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Performance Comparison

Horsepower

   • M235i: ~320 hp

   • M240i: ~335 hp

The difference isn’t massive on paper, but the M240i benefits from improved engine efficiency.

Torque

   • M235i: ~330 lb-ft

   • M240i: ~369 lb-ft

This torque difference is where the B58 really shines.

Acceleration

Typical acceleration figures:

   • M235i: ~4.6 seconds (0–60 mph)

   • M240i: ~4.3 seconds (0–60 mph)

With xDrive models, times can drop even further.

Real-World Driving Differences

In real-world driving:

   • The M240i feels quicker, especially at highway speeds.

   • The M235i still delivers excellent performance and feels very engaging.

For most drivers, both cars are fast enough to be exciting daily drivers and weekend track toys.

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Tuning Potential and Aftermarket Support

One of the reasons enthusiasts love the BMW F22 platform is its strong tuning potential.

Popular Modifications

Common upgrades for both the M235i and M240i include:

   • ECU tuning

   • Downpipes

   • Intake systems

   • Intercooler upgrades

   • Turbo upgrades

   • Performance exhaust systems

   • Suspension upgrades

   • Alcantara interior trim

   • Limited-slip differentials

These modifications can dramatically improve performance.

Why Enthusiasts Modify These Cars

The BMW F22 M235i and M240i provide an excellent balance of:

   • Lightweight chassis

   • Strong turbocharged engines

   • Good factory performance

This makes them ideal platforms for street builds, track cars, and high-performance daily drivers.

Potential Horsepower Gains

Approximate tuned power levels:

M235i (N55)

   • Stage 1: ~360–380 hp

   • Stage 2: ~400+ hp

   • Upgraded turbo: 450+ hp possible

M240i (B58)

   • Stage 1: ~380–400 hp

   • Stage 2: ~420–450 hp

   • Hybrid turbo builds: 500+ hp achievable

The B58 engine generally supports higher power levels more easily.

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Which One Should You Choose?

Best for Budget Buyers

The BMW M235i is typically the more affordable option on the used market.

It offers:

   • Strong performance

   • Proven N55 engine

   • Lower purchase price

For buyers seeking maximum value, the M235i is an excellent choice.

Best for Performance Enthusiasts

If your goal is the fastest and most capable version, the BMW M240i is the better option.

Benefits include:

   • More power

   • Stronger B58 engine

   • Better tuning potential

Best Platform for Modifications

While both platforms are excellent for modifications, the M240i often wins for serious builds because the B58 engine can handle more power.

However, the N55 in the M235i still offers excellent tuning results and remains extremely popular in the aftermarket community.

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Conclusion

The BMW F22 M235i vs BMW M240i comparison ultimately comes down to engine technology and performance upgrades.

The M235i delivers:

   • Classic BMW inline-six character

   • Engaging driving dynamics

   • Strong performance at a lower price point

The M240i improves the formula with:

   • The newer B58 engine

   • More torque and faster acceleration

   • Greater tuning potential

In a BMW 2 Series performance comparison, both cars remain excellent choices for enthusiasts who want a compact, rear-wheel-drive performance coupe.

If you’re looking for the best value and a proven engine, the M235i is a fantastic option. But if you want maximum performance and future tuning potential, the M240i—with its B58 engine—takes the crown.

Either way, both cars represent one of the last truly compact performance coupes from BMW, and that alone makes them special in today’s automotive landscape.