BMW M135i: AWD or FWD?

The arrival of the new generation BMW 1-Series has been a significant event in the compact executive car segment. At the forefront of this new line-up is the potent BMW M135i, a model that has historically represented the pinnacle of performance for the 1-Series. However, this latest iteration marks a fundamental shift from its predecessors, most notably in its underlying architecture. This move away from BMW's traditional rear-wheel drive (RWD) heritage to a front-wheel drive (FWD) platform has sparked considerable discussion among enthusiasts and potential buyers alike. This article aims to explore the intricacies of the M135i, focusing on its drivetrain, performance characteristics, and the overall driving experience it offers.

A New Platform, A New Direction

The third generation BMW 1-Series, and specifically the M135i model, is built upon a completely new platform architecture. This is a departure from the rear-wheel drive architecture that has defined the 1-Series for generations. The new platform, shared with Mini and other BMW 2-Series models, is inherently front-wheel drive. This change brings with it several advantages, including a weight reduction of up to 30 kg, increased interior space, particularly for rear passengers and luggage, and a more cost-effective manufacturing process. However, the most significant implication of this architectural shift lies in the fundamental alteration of the car's driving dynamics.

Drivetrain and Performance Figures

Under the bonnet, the 2020 BMW M135i is powered by a 2.0-litre four-cylinder turbocharged engine. This powerplant delivers a substantial 306hp and 450Nm of torque. When it comes to acceleration, the M135i is impressively quick, capable of completing the 0-100 km/h sprint in approximately 4.8 seconds. While this is a formidable figure, it is marginally slower than its six-cylinder predecessor from 2016, which achieved the same benchmark in 4.7 seconds. The top speed is electronically limited to 250 km/h, a common practice for performance vehicles in this class.

The All-Wheel Drive Question: xDrive Explained

So, does the BMW M135i have all-wheel drive? The answer is yes, but with a crucial distinction. The M135i is equipped with BMW's xDrive all-wheel drive system. However, this system is not a permanent, full-time affair in the traditional sense. In its standard configuration, and particularly in Comfort and Eco Pro driving modes, the xDrive system prioritises sending power to the front wheels. It is only when slip is detected or when the car is in Sport mode that torque is distributed to the rear wheels, with a maximum of 50% of the torque capable of being sent rearward. This means that while it has AWD, its behaviour is heavily biased towards front-wheel drive, especially during less demanding driving conditions or lower rev ranges.

Driving Dynamics: The FWD Influence

The shift to a front-wheel drive architecture, even with the xDrive system, has a palpable effect on the M135i's driving experience. BMW has invested considerable effort in mitigating the traditional drawbacks of FWD, such as torque steer. The M135i features a rigid chassis, M Sport steering, and a new ARB (Actuatorcontiguous Wheel Slip Limitation) system coupled with BMW Performance Control. This system actively brakes the inside wheel during cornering to enhance agility and reduce understeer. Despite these technological interventions, a noticeable amount of torque steer can still be felt, particularly under strong acceleration. This tendency for the steering wheel to pull to one side is more pronounced than one might expect, even with the electronic and mechanical measures in place to counter it.

The suspension setup is decidedly sporty, even in the Comfort mode. The ride can feel firm, with short, sharp bumps being transmitted directly into the cabin. This characteristic was also evident even in the more comfort-oriented 118d model, suggesting a consistent tuning philosophy across the range. On the positive side, the M135i can be steered through bends with remarkable speed and precision. The steering inputs are direct, and the car exhibits only minor tendencies towards understeer. The overall driving experience, particularly the way power is delivered and how the car handles, bears a striking resemblance to that of a Mini Cooper S, another vehicle within the BMW Group that utilises a similar FWD platform.

Interior and Technology

The interior of the new 1-Series is described as conservative in its changes, retaining a significant number of physical buttons that many competitors have moved away from. Ergonomics and the seating position are excellent, and the materials used contribute to a premium feel. The infotainment system, iDrive, is packed with features but can be overwhelming due to its complexity. With over 1,000 options and functions, finding specific settings can be a challenge, suggesting that a refresh of the iDrive software and menu structure would be beneficial.

Optional extras can significantly enhance the M135i's appeal, transforming it into a well-equipped compact luxury car. Features like adaptive cruise control, ambient lighting, and a panoramic sunroof add to the premium experience. The head-up display is a particularly noteworthy addition, providing not only speed and navigation but also crucial information like the current and upcoming speed limits. The digital key functionality, allowing the car to be unlocked via a smartphone even with a depleted battery, is a futuristic touch. However, the wireless charging bay is quite narrow, barely accommodating a larger smartphone with a protective case.

Sound and Overall Impression

A point of contention for many enthusiasts will be the sound produced by the four-cylinder engine. In terms of auditory experience, it simply cannot match the rich, sonorous tone of its six-cylinder predecessor. While the interior sound deadening is effective, creating a tolerable soundtrack within the cabin, the exterior noise is relatively subdued and unspectacular, save for the occasional pops and crackles on startup. This sonic difference is often compared to the shift from the Porsche 718 Cayman's flat-six to its current four-cylinder Boxer engine.

In summary, the new BMW M135i presents a compelling package with its attractive design, extensive equipment options, and efficient powertrain. However, the adoption of a front-wheel drive architecture and the move to a four-cylinder engine have undeniably altered its character. While it remains a fast and capable car, the fundamental changes in its drivetrain and the resulting impact on its handling and sound profile mean it offers a distinctly different driving experience compared to its rear-wheel drive ancestors. Whether this evolution is a positive step will ultimately depend on individual driver preferences and priorities.

Frequently Asked Questions

Is the BMW M135i rear-wheel drive?

No, the latest generation BMW M135i is based on a front-wheel drive architecture. It does feature xDrive all-wheel drive, but it is primarily front-biased, sending power to the rear wheels only when needed.

What engine is in the BMW M135i?

The 2020 BMW M135i is equipped with a 2.0-litre four-cylinder turbocharged petrol engine producing 306hp.

How fast is the BMW M135i?

The M135i can accelerate from 0 to 100 km/h in approximately 4.8 seconds, with a top speed limited to 250 km/h.

What is the main difference between the new M135i and the old one?

The most significant difference is the shift from a rear-wheel drive platform to a front-wheel drive architecture. This also involves a change from a 3.0-litre six-cylinder engine to a 2.0-litre four-cylinder engine.

Does the M135i have torque steer?

Yes, despite efforts to mitigate it, the M135i can exhibit noticeable torque steer, particularly under strong acceleration, due to its front-wheel drive bias.