BMW S58 engine explained: the twin-turbo straight-six of modern M cars

The BMW S58 engine is the twin-turbo straight-six at the heart of today's M cars. Introduced in 2019, it powers the M3, M4, M2, X3 M and X4 M, with outputs that have grown with every new version.

It continues a long BMW tradition of high-performance straight-six engines, but with modern technology for strength, cooling and efficiency. In this article we explain how the S58 is built, which models use it, how it differs from road-car engines and what owners should know about maintenance.

Where the S58 comes from

BMW M has built straight-six engines for decades, from the M88 of the M1 to the S54 of the E46 M3 and the S55 of the F80 M3. Our article on the history of the BMW straight-six engine tells that story.

The S58 was developed as the successor to the S55. It shares its basic layout with BMW's modular engine family, including the B58 used in many regular BMW models. However, M engineers changed most of the important parts to handle much higher power, sustained track driving and higher engine speeds. The letter S in the name shows that it is an M engine. Our article on BMW engine codes explains how these names work.

How the BMW S58 engine is built

The BMW S58 engine is a 3.0-litre inline six-cylinder with two turbochargers. Its key design features include:

• A closed-deck crankcase, which makes the block very stiff and able to handle high cylinder pressures.
• A forged crankshaft, strong and relatively light.
• A cylinder head whose core is made with 3D printing, which allows coolant passages that would be impossible with traditional casting.
• Two mono-scroll turbochargers, each feeding three cylinders, with electronically controlled wastegates.
• High-pressure direct injection, for precise fuel delivery and good efficiency.
• Variable valve timing, for a wide spread of torque. Our article on BMW VANOS explains how this works.

The result is an engine that pulls strongly from low revs and continues to rev freely towards its limit.

Cooling and oil supply for track use

M cars must survive repeated laps on a circuit, where engines are under full load for long periods. The S58 has a cooling system with several radiators and coolers for the engine, charge air, oil and gearbox.

The oil supply is designed to work under high lateral forces. A map-controlled oil pump and an oil sump designed for track use keep oil available even in long, fast corners and under heavy braking.

These features are a big part of the difference between an M engine and a regular road-car engine. They allow the car to be driven hard without losing performance because of heat.

Models and power outputs

The S58 has been used in several M models, with different outputs depending on the car and version:

• X3 M and X4 M: the first models with the S58.
• M3 (G80) and M3 Touring (G81).
• M4 coupé and convertible (G82 and G83).
• M2 (G87), in a slightly lower power version.
• Limited models such as the M4 CSL and M3 CS, with the highest outputs.

Power in the M3 and M4 started at 480 hp for the standard models and 510 hp for the Competition, with later updates and special models delivering more. Exact outputs depend on the market and model year, so always check the official data for a specific car.

S58 compared with the S55

Compared with the S55 of the F80 M3 and F82 M4, the S58 offers:

• More power and torque, with a broader spread of performance.
• Freer revving and a smoother character at high engine speeds.
• Improved cooling and oil supply for sustained track use.
• More potential for higher outputs in special models.

The S55 still feels lively and urgent, and some drivers prefer its rawer character. Our comparison of the M3 G80 and M3 F80 explains how this difference affects the driving experience.

Maintenance and reliability

The S58 has a good reputation so far, but like every high-performance turbo engine it depends on correct maintenance:

• Oil changes: use oil with the correct BMW approval and consider shorter intervals if you drive on track. Our article on BMW M engine oil explains the requirements.
• Warm-up: let the oil reach operating temperature before using high revs. Our article on how to warm up a BMW M engine explains why.
• Spark plugs: turbo engines need healthy plugs to avoid misfires.
• Cooling system: check coolant levels and look for leaks around radiators and hoses.
• Software updates: a BMW service partner can install updates that improve running and diagnostics.

Many owners also tune the S58. Any tuning must be legal in your country and can affect warranty and reliability.

Why the S58 matters

The S58 shows that a turbocharged engine can still feel like a true M engine. It combines the torque of modern turbo technology with a willingness to rev, a strong sound and the durability needed for track use.

For buyers of modern M cars, the S58 is one of the main reasons to choose a G-series model. For enthusiasts, it continues the story of the BMW M straight-six into a new era.

BMW S58 engine at a glance

Item	Details
Introduced	2019
Layout	3.0-litre inline six-cylinder, twin-turbo
Crankcase	Closed-deck design
Crankshaft	Forged
Cylinder head	Core made with 3D printing
Models	X3 M, X4 M, M3, M4, M2 and special models
Successor of	S55 (F80 M3, F82 M4, F87 M2 Competition)

Frequently asked questions

Is the BMW S58 engine reliable?

It has a good reputation so far. Correct oil, regular servicing and a proper warm-up are the most important factors.

Is the S58 based on the B58?

It shares its basic layout with the B58 family, but most important parts are changed by BMW M for higher power and track use.

Which cars have the S58 engine?

The X3 M, X4 M, M3 G80, M3 Touring G81, M4 G82 and G83, M2 G87 and special models such as the M4 CSL.

What is the difference between the S55 and S58?

The S58 has more power, revs more freely and has improved cooling and oil supply for track use.

Sources

• BMW Group PressClub – BMW M3 and M4 (G80, G82) press kits with S58 engine
• BMW M GmbH – official model information