The B58 excels in daily driving with ample power and excellent tuning potential at a great value. The S58, being the high-performance variant, caters to those seeking top-end power and extensive tuning capabilities. 

 

Introduction

BMW's B58 and S58 engines are benchmarks in the world of turbocharged inline-6 engines. Introduced in 2015 and 2019, respectively, these engines have set new standards in performance, tuning, and reliability​.

Performance and Technical Specifications

• B58 Engine:

  • Horsepower: 322–382 hp
  • Torque: 332–369 lb-ft
  • Turbocharger: Single twin-scroll
  • Compression Ratio: 11.0:1
  • Redline: 7,000 rpm

• S58 Engine:

  • Horsepower: 453–503 hp
  • Torque: 443 lb-ft
  • Turbocharger: Twin mono-scroll
  • Compression Ratio: 9.3:1
  • Redline: 7,200 rpm​.

Driving Experience

• B58: Renowned for its exceptional low-end torque and minimal turbo lag, making it ideal for daily driving. Its linear powerband and impressive stock performance make it a step below a true M-engine.
• S58: Known for its high torque at low RPMs and remarkable performance at high RPMs, reminiscent of high-revving engines like the S54​.

Tuning Potential

• B58 Tuning: Offers great value for reliable power gains. With simple modifications, it can gain significant torque and horsepower, making it a favorite among tuners for its cost-effectiveness and impressive results.
• S58 Tuning: exhibits even higher potential for tuning than the B58. Capable of reaching higher horsepower with similar mods, it benefits from a stronger engine block and forged internals, making it suitable for aggressive tuning​.

Sound Comparison

• B58 Sound: Praised for its superior exhaust note. The single turbo setup allows for a louder, more refined sound, especially with aftermarket modifications.
• S58 Sound: Slightly muffled due to the twin-turbo setup. While it offers an improvement over the S55, it doesn't quite match the auditory appeal of the B58​​.

Reliability

• B58 Reliability: Proven to be one of the most reliable turbocharged BMW engines, comparable to the naturally-aspirated N52. Known for its durability even under aggressive tuning and high mileage.
• S58 Reliability: While still relatively new, it's expected to be reliable. However, its increased complexity and higher power output might introduce more potential points of failure compared to the B58​

Conclusion

The B58 and S58 are both exceptional in their respective realms. The B58 excels in daily driving with ample power and excellent tuning potential at a great value. The S58, being the high-performance variant, caters to those seeking top-end power and extensive tuning capabilities. Each engine, with its distinct characteristics, upholds BMW’s legacy of engineering excellence, offering enthusiasts a choice between refined daily usability and exhilarating high-performance driving.