Displacement: 2,998 cc
The heart of the M340i is the B58 3.0-liter TwinPower Turbo inline-six engine. For 2026, this powerplant is augmented by a 48V mild-hybrid system that provides smoother auto start-stop transitions and an electric torque boost. The engine utilizes an aluminum block and head with a twin-scroll turbocharger and direct high-pressure injection.
Max Power: 386 hp (391 PS)
In its latest 2026 calibration, the turbocharged inline-six produces a peak output of 386 horsepower. This power is delivered linearly across the rev range, peaking between 5,200 and 6,250 rpm. The mild-hybrid motor contributes an additional 11 hp of temporary overboost during hard acceleration.
Max Torque: 500 Nm
The M340i generates a massive 500 Nm (approximately 369 lb-ft) of torque, available from as low as 1,900 rpm. This low-end grunt ensures effortless overtaking and a broad power band that remains consistent through to the upper limits of the tachometer.
No. of Cylinders: 6 (Inline)
BMW remains committed to its signature straight-six configuration, which offers inherent primary and secondary balance. The 2026 model retains this setup for the M340i, while the 330i and 330e variants utilize a 2.0-liter, 4-cylinder engine ($1,998$ cc).
Valve Train: DOHC with Valvetronic
The engine features a Double Overhead Camshaft (DOHC) design with 4 valves per cylinder. It incorporates BMW's proprietary Valvetronic fully variable valve lift and Double-VANOS variable camshaft timing on both the intake and exhaust sides for optimized breathing.
Fuel System: GDI (High Precision Injection)
Fuel is delivered via High Precision Direct Injection (GDI) with a maximum injection pressure of 350 bar. This ensures finer atomization of fuel, leading to more efficient combustion, lower emissions, and increased power density.
0-100 km/h: 4.4 seconds
Equipped with xDrive all-wheel drive and Launch Control, the 2026 M340i sprints from 0 to 100 km/h in just 4.4 seconds. The plug-in hybrid 330e follows at approximately 5.8 seconds, utilizing its 12 kWh (gross) battery for immediate electric torque assistance.
Top Speed: 250 km/h
The top speed is electronically limited to 250 km/h (155 mph). In certain regions, the car can be specified with increased cooling and performance tires that raise the speed governor, though the standard limit complies with voluntary German manufacturer agreements.
