Discover the Most Power-Dense Engine Ever Created by BMW

BMW has long been recognized for its exceptional straight-six engines, adept at generating remarkable horsepower and torque. This engineering prowess has been a hallmark of their vehicles for several decades, particularly in their high-performance M models, like the M3. The automaker first introduced a robust straight-six engine in 1972, featuring it in the inaugural version of the BMW 3.0 CSL.

Recently, BMW decided to revive the legendary 3.0 CSL nameplate, bringing back the essence of its original 3.0-liter straight-six engine. This move resulted in the creation of BMW’s most power-dense engine to date, a variant of the current B58 straight-six, with significant modifications to enhance its performance. CarBuzz set out to honor this impressive engine, as it holds a significant place in automotive history. Read on to discover more about it.

The following write-up contains information, specs, and history sourced directly from BMW’s M-division website.

BMW’s Powerhouse: S58B30T0 Hot-Six

What Makes It So Special?

• A power density of 184 hp.
• 308.2 hp per ton.
• Engine featured in BMW’s first CSL model in 20 years.
• Generates substantial power from a compact engine.
• Incorporates advanced technology to achieve its output.

Enter the BMW S58B30T0, a straight-six engine designed with race-inspired performance. What sets this engine apart is its unique configuration found exclusively in the 2023 BMW 3.0 CSL, producing an impressive 552 horsepower, translating to a specific power output of 184 hp per liter. While this is not the highest, it remains competitive, almost matching the formidable turbocharged three-cylinder in the GR Corolla. The S58B30T0 belongs to BMW’s B58 straight-six engine family, a lineage that dates back nine years and has powered a range of vehicles from the energetic BMW 340i to the dynamic BMW M3 CS. In essence, these engines are well-versed in delivering exhilarating performance.

Guided by the philosophy of “The Ultimate Driving Machine”, the S58B30T0 needed to be outstanding, especially since it powers the remarkable 3.0 CSL, an emblematic name that resonates strongly within BMW’s history. The automaker clearly understood this weighty expectation and succeeded in crafting a power unit that not only fulfills but surpasses the expectations associated with the CSL name.

The What, Why, And How Of The S58B30T0

The engine in the 2023 model significantly outperforms its predecessor found in the original 3.0 CSL from 1972, which delivered only 203 horsepower and 211 lb-ft of torque. Although this was impressive for its time when it raced against other competitors, the current model easily eclipses it in power and performance.

This modern marvel achieves its impressive output thanks to a comprehensive combination of engineering elements. As noted, the S58B30T0 engine is a performance-oriented variation of BMW’s B58 engine family. True to tradition, the current 3.0 CSL utilizes a straight-six setup, emphasizing the heritage of the brand. Turbocharging further enhances the output, resulting in 552 horsepower.

Alongside turbocharging, the S58B30T0 features numerous enhancements. Included are a lightweight molybdenum-steel crankshaft for effective heat management and torsion resistance, along with forged steel connecting rods and forged aluminum pistons to reduce overall engine weight while boosting strength. Its compression ratio stands high at 11.0:1, compared to the 9.3:1 ratio found in regular B58 motors.

These advancements culminate in a substantial 552-horsepower and 406 lb-ft of torque rating. Furthermore, the S58B30T0 can rev up to an impressive 7,200 rpm, marking it as a high-performance straight-six engine. In summary, the powertrain in the 2023 BMW 3.0 CSL is a formidable piece of engineering.

How The S58B30T0 Came To Be

The S58B30T0 evolved from the standard B58 engine, a powerful option that has been used in popular models such as the BMW 340i and BMW 740i. Its development can be traced back even further to the previous N55 straight-six engines. Notable applications of the N55 include the 2017–2020 BMW M4 CS and the 2020–2021 BMW M2 CS.

In 2015, BMW commenced the development of the new straight-six engine, paving the way for the B58 and its subsequent iterations, phasing out the older N55 models.

BMW’s commitment to inline-six engines has remained steadfast, driven by their advantages in manufacturing, balanced performance, and smooth operation. Given their dedication to this engine configuration, it seems the BMW straight-six will continue to be a prominent feature for the foreseeable future.

How The New 3.0 CSL Dominates A Track

Beyond its extraordinary engine, the 2023 BMW 3.0 CSL’s impressive track capabilities stem from numerous other precisely engineered components.

One of the essential factors for any car excelling on a track is its weight. The engineers at BMW recognized this, and thus the modern 3.0 CSL’s body is primarily constructed from carbon fiber reinforced plastic (CFRP). Additionally, the 3.0 CSL forgoes virtually all sound-insulating material, resulting in an interior that resonates with the thrilling sounds of a high-performance vehicle. To further optimize weight, BMW innovatively crafted a new titanium rear exhaust diffuser, shedding about ten pounds—an effort that showcases their commitment to weight savings for unparalleled speed.

Another exceptional feature of the BMW 3.0 CSL is its six-speed manual transmission. While BMW continues to provide manual options in models such as the M2, M3, and M4, the era of BMW vehicles equipped with manual gearboxes might soon be coming to a close, as reflected in trends across the automotive industry. For instance, Volkswagen has recently announced that the beloved Golf GTI will no longer offer a manual transmission.

If you’ve read through this piece and are longing to own a BMW 3.0 CSL, you’ll have to act quickly. BMW produced only 50 units of this model, and they all sold out promptly. However, if you have deep pockets and patience, you may find a pre-owned unit available for sale eventually. Recently, a unit sold at RM Sotheby’s auction for around $1.1 million. Until then, aspiring owners might have to settle for merely admiring photos and dreaming of experiencing the thrill of one of BMW’s greatest cars.