The Straight-Six That Powers 41 Fashions (and Counting)

Since launching in 2015, BMW’s B58 inline-six has develop into a real spine for the model—and past. Throughout 41 distinct mannequin purposes, it has powered the whole lot from the three Collection to the 7 Collection, and even the Toyota Supra, Morgan Plus Six, and the Ineos Grenadier. In late 2025, BMW made a daring assertion: it’s nonetheless evolving the B58. The M240i, M340i, and M440i will get a revamped model that reinforces output to 386 hp and 540 Nm, lowers gasoline consumption, and tightens 0–100 occasions—a reminder that even a decade in, this contemporary straight-six hasn’t misplaced its edge. In an period when most engines are specialised, short-lived, or restricted to slim segments, the B58 has develop into a real workhorse.

What the B58 Is

The B58 belongs to BMW’s modular engine household, sharing structure with the four-cylinder B48 and six-cylinder diesel B57. It displaces 3.0 liters, with a single twin-scroll turbocharger feeding all six cylinders. In contrast to its predecessor, the N55the B58 was designed with a closed-deck block, making it stronger and higher in a position to stand up to larger pressures. An built-in water-to-air intercooler sits throughout the consumption plenum, shortening airflow paths and enhancing effectivity.

From the outset, BMW engineered the B58 not just for effectivity and emissions compliance but additionally for refinement and sturdiness. Clean, torquey, and surprisingly economical in each day driving, it carries ahead BMW’s lengthy custom of silky inline-sixes.

Variations and Technical Updates

Over its decade of manufacturing, the B58 has appeared in a number of distinct variations, every tuned for a particular function. Early fashions just like the B58B30M0 powered the F30 340i, producing between 322 and 335 horsepower. Later got here hotter variations such because the B58B30O1, which delivered as a lot as 382 horsepower in automobiles just like the M340i and Z4 M40i, and as much as 434 horsepower within the Toyota GR Supra A90 Closing Version.

BMW has regularly refined the design via “Technical Updates,” or TU iterations. These included element modifications to enhance emissions, gasoline effectivity, and efficiency. The latest B58TU2 now powers the newest 5 Collection (G60) and seven Collection (G70), producing round 388 horsepower whereas assembly the strictest rules worldwide.

This means to evolve has stored the B58 related throughout altering generations, from the F30 and F32 period of the mid-2010s to the most recent G60 5 Collection and past.

Why the B58 Works So Properly

What units the B58 aside is steadiness. It produces ample low-end torque, but revs cleanly towards the highest of the dial. It’s sturdy sufficient for efficiency automobiles just like the Supra, but refined sufficient for luxurious cruisers just like the 7 Collection. BMW solved lots of the shortcomings of its earlier turbocharged sixes—the N54’s fragility and the N55’s restricted headroom—by over-engineering the B58 from the beginning.

It additionally earned recognition outdoors of fanatic circles, touchdown a number of occasions on Ward’s 10 Finest Engines record (2016, 2017, 2019, 2020). For journalists and engineers alike, it turned the benchmark for a contemporary turbo inline-six.

Past BMW

The B58’s status has carried it past Munich. As we already talked about, Toyota trusted it to convey the Supra nameplate again to life, whereas Morgan selected it for its Plus Sixmixing old-world craftsmanship with fashionable reliability. Ineos adopted a detuned model for the Grenadier off-roader, counting on its sturdiness in punishing situations. Even small-scale German outfits like Boldmen constructed automobiles round it.

That breadth is uncommon. Engines not often cross model strains in right this moment’s automotive world, but the B58 has confirmed common sufficient to win belief from carmakers with vastly totally different philosophies.

The Final Nice Inline-Six?

As BMW prepares to roll out the all-electric Neue Klasse platform, the B58’s future function may shrink. However within the meantime, it stays the spine of the lineup. Ten years after its debut, it continues to anchor the whole lot from the M240i to the X7.

For fanatics, it could be remembered because the final actually nice BMW straight-six—a contemporary basic that carried the model via a transitional decade. Very like the M30 of the Seventies or the naturally aspirated S54 of the early 2000s, the B58 has already secured its place in BMW historical past. And hopefully, that historical past will proceed for many years to return since BMW has as soon as once more reaffirmed their dedication to ICE automobiles.