BMW B58
B58B30O1 in a G22 M440i
Overview
Manufacturer	BMW
Production	2015–present
Layout
Configuration	Straight-six
Displacement	3.0 L (2,998 cc)
Cylinder bore	82 mm (3.23 in)
Piston stroke	94.6 mm (3.72 in)
Cylinder block material	Closed-deck aluminium
Cylinder head material	Aluminum
Valvetrain	DOHC 4 valves x cyl. with Valvetronic and Double VANOS
Valvetrain drive system	Chain
Compression ratio	11.0:1
RPM range
Max. engine speed	7,000 rpm
Combustion
Supercharger	48V electrical systems Starter Generator (2020; some models)
Turbocharger	Single twin-scroll turbocharger with air-to-liquid intercooler
Fuel system	Direct injection
Management	Bosch Di-Motronic
Fuel type	Petrol
Oil system	Wet sump with water heat exchanger
Cooling system	Water-cooled
Output
Power output	210–285 kW (282–382 hp)
Torque output	450–500 N⋅m (332–369 lb⋅ft)
Dimensions
Dry weight	139 kg (306 lb)
Chronology
Predecessor	BMW N55

B58B30C in a 2020 Toyota Supra

The BMW B58 is a turbocharged straight-six engine, which began production in 2015.^[1] The B58 replaced the N55 and was launched in the F30 340i.^[2]

The B58 is part of BMW's new modular engine family, each engine using a displacement of 500 cc (30.5 cu in) per cylinder, following the B38 and B48 engine.^[3]

The B58 engine was named to Ward's World's 10 Best Engines 4 times, in 2016 (installed in the 340i),^[4] 2017 (M240i),^[5] 2019 (X5)^[6] and 2020(M340i).^[7]

The S58 engine, which was released in early 2019, is the high-performance version of the B58.^[8][9] It was named to Ward's World's 10 Best Engines in 2023 (installed in the M2).^[10]

Design

Compared with its BMW N55 predecessor, the B58 features a 20% increase in boost pressure, a closed-deck engine block design, an increase in compression ratio to 11.0:1 and a slight increase in displacement from 2,979 to 2,998 cc (181.8 to 182.9 cu in) with added weight of 8 kg (18 lb).

The turbocharger is a twin-scroll design, for more efficient power delivery with less turbo lag and more power than a conventional single turbocharger, as well as for weight and space saving benefits.^[11] The intercooler - a water-to-air design - is integrated into the intake plenum, to reduce the volume of air between the turbocharger and the cylinders.^[12][13]

As per the N55, the B58 also features direct fuel injection, variable valve timing (called double Vanos by BMW), and variable valve lift (called Valvetronic by BMW).^[14][15] The redline remains at 7,000 rpm, the bore and the stroke is 82 mm × 94.6 mm (3.23 in × 3.72 in).

The B58 also features an engine-mounted heat encapsulation system to reduce engine wear and emissions during start-up.^[16]

For durability and longevity, the rotating assembly has a forged steel crankshaft and forged connecting rods.^[17][18]

As a part of BMW's new modular engine family, the crankcase is a completely new design identical to the B57 diesel version,^[19] engineered as both a gasoline and diesel engine in one common part. The closed deck crankcase is equipped with a completely new structure which can be identified by a complex array of ribs on the exhaust and intake side and an additional reinforcement frame on the oil pump side.

The engine was revised in 2018, dubbed "B58TU", with notable changes and improvements. The fuel system was updated with 75% increased pressure with updated high pressure fuel pump and injectors, a new particulate filter in the catalytic converter, a new one-part timing chain as opposed to the earlier two-part, and new separate cooling circuits for the cylinder head and crankcase. For weight savings, the crankcase wall thickness and forged crankshaft were optimized, and the exhaust manifold was integrated into the cylinder head housing.^[20]

B58B30M0 in a F30 340i

Models

S58

BMW S58 engine
Overview
Production	2019–present
Layout
Configuration	Straight-six
Displacement	3.0 L (2,993 cc)
Cylinder bore	84 mm (3.3 in)
Piston stroke	90 mm (3.5 in)
Cylinder block material	Closed-deck aluminum
Cylinder head material	Aluminum
Valvetrain	DOHC w/ VVT & VVL
Compression ratio	9.3:1
RPM range
Max. engine speed	7,200 RPM
Combustion
Turbocharger	Twin-Turbo with air-to-liquid intercooler
Fuel system	Direct injection
Fuel type	Petrol
Output
Power output	338–375 kW (453–503 hp)
Torque output	550–650 N⋅m (406–479 lb⋅ft)
Chronology
Predecessor	BMW S55

The S58 engine is the high-performance version of the B58 engine. It was introduced in the F97 X3 M and F98 X4 M, marking the first time a stand-alone M model was produced for the X3 and X4.^[30]

The S58 features twin mono-scroll turbochargers, a compression ratio of 9.3:1, a redline at 7,200 rpm with the bore and the stroke at 84 mm × 90 mm (3.31 in × 3.54 in). It also features a forged chrome molybdenum heat-treated steel crankshaft, plus forged steel connecting rods and forged aluminum pistons. The pistons are forged by Mahle and feature their proprietary anti-friction coating.^[31]

Like the B58, the S58 also features direct fuel injection, variable valve timing (called double Vanos by BMW), and variable valve lift (called Valvetronic by BMW).

As opposed to the B58, the S58 features a slightly smaller displacement, increased bore, decreased stroke, and larger valves. Compression is decreased to 9.3:1 from 11.0:1. The S58 favors top-end power and has a higher redline of 7,200 RPM.^[31]

References