New ISG (Integrated Starter Generator) Technology

The ISG installed in the S 450 is an electric motor positioned between the engine and transmission, producing a maximum output of 16 kW and a maximum torque of 250 Nm. It operates as part of a 48V mild hybrid system, also serving as the alternator and starter.

In addition to generating electricity through regenerative braking and charging a lithium-ion battery with a capacity of approximately 1 kWh, it uses its power to assist the engine at low RPMs, achieving high efficiency and strong acceleration.

Mercedes-Benz S 450 Long

Furthermore, the high-output electric motor acting as the starter suppresses engine start-up vibrations and enables smoother restarts from idling stop.

The system also incorporates a feature that prevents engine shutdown if the system predicts, based on driving data and radar sensor information, that the stop will be less than two seconds, as fuel consumption increases in such cases compared to not stopping at all.

Simultaneously, by adjusting the charging current of the electric motor during idling, the engine speed is stably maintained at a low 520 rpm, enhancing efficiency, comfort, and quietness. The 48V electrical system provides sufficient power for propulsion assistance while remaining below 60V, eliminating the need for dedicated occupant protection systems.

New Inline-Six Engine Adopted for the First Time in 20 Years

The newly developed 3.0-liter inline-six direct-injection turbo engine, the "M256," powering the S 450, is the first engine designed with electrification in mind. It produces a maximum output of 270 kW (367 ps) and a maximum torque of 500 Nm on its own.

The long, front-to-back shape of inline-six engines previously made them unsuitable for crumple zones, leading to their replacement by V-engines. However, with the electrification of accessories like the air conditioning and water pump, which were previously driven by the engine's rotation, the belt-driven devices at the front of the engine are no longer necessary, allowing for a more compact design.

This creates space on either side of the engine for ancillary components. Most importantly, the reduced vibration and smoother engine feel make this the first return to an inline-six engine for Mercedes-Benz in 20 years, since 1997.

As expected of a modern engine, it features close-coupled catalytic converters for more efficient exhaust gas treatment and NANOSLIDE friction-reducing coating on the cylinder walls, a steel-carbon material application, to reduce friction loss.

The boosting system employs two turbochargers: an "electric supercharger" for low-speed boost and an exhaust gas turbocharger. This eliminates turbo lag, and combined with the ISG's power assist, provides agile response across all RPM ranges.

Pricing starts at 11.47 million yen for the S450, 13.63 million yen for the S450 Exclusive with enhanced equipment, and 14.73 million yen for the S450 Long, which is 13 cm longer to provide more rear legroom. Deliveries are scheduled to begin around April of this year (around summer for the S450 Long).

Mercedes-Benz S450
Body Dimensions | Length 5,125 x Width 1,899 x Height 1,493 mm
Wheelbase | 3,035 mm
Engine | 2,999 cc Inline-6 Cylinder Direct Injection DOHC Turbo
Compression Ratio | 10.5
Max Output | 270 kW (367 ps) / 5,500-6,100 rpm
Max Torque | 500 Nm (51.0 kgm) / 1,600-4,000 rpm
Transmission | 9-Speed AT
Drivetrain | FR
Brakes Front/Rear | Ventilated Discs / Ventilated Discs
Trunk Capacity | 510 - 530ℓ
Tires Front/Rear | 245/50R18 / 245/50R18 / (Exclusive) 245/50R18 / 275/40R19
Steering Position | Left / Right
Price | (S450) 11.47 million yen / (Exclusive) 13.63 million yen / (Long) 14.73 million yen