2025 4 Series Increases Efficiency And Responsiveness With 48V Mild Hybrid System - BimmerLife

Alongside the M4 Coupe and Convertible updates for 2025, the non M flavors also received some attention from BMW designers and engineers. The 4 Series lifecycle update includes enhancements to the interior, exterior, and 48V mild hybrid integration for the four-cylinder 430i and six-cylinder 440i models.

The new B58B30M2 3.0-liter straight-six engines found in the 2025 M440i gains a modest eleven horsepower (via the 48V starter generator) from the mild hybrid system integration. This boosts the existing 375 horses to a total system output of 386 @ 5,200-6,250 rpm, accompanied with 398 lb-ft of torque @ 1,900-4,800 rpm.

The B48B20O2 2.0-liter inline four-cylinder engines in the 2025 430i receive the 48V mild hybrid system—but wait there’s more. In addition to the hybrid system, efficiency is improved by the incorporation of the Miller-cycle combustion process—a combustion cycle used in forced-induction engines where intake valve remains open during part of the compression stroke, which means the engine is compressing against the pressure of the turbocharger instead of the pressure of the cylinder walls.

The four banger also sees a redesign of the intake ports and combustion chambers, and improvements in camshaft control, injection, the ignition system, and exhaust gas routing. All of these updates result in a total system output of 255 hp @ 4,700-6,500 rpm, and 295 lb-ft of torque @ 1,600-4,500 rpm.

In addition to new LED headlights up front, BMW’s new Laserlight taillights make an appearance. BMW says, “The LED headlights are paired with the visually and technologically impressive design of the Laserlight taillights, which are standard on M440i models and part of the optional Shadowline Package on 430i models. These units feature laser diodes illuminating glass fiber bundles, producing attractive 3-dimensional light graphics which complement the taillight clusters.” This isn’t the last we’ll be seeing of these.

Further sharpening the exterior, M440i models receive a new kidney grille—no, it’s not smaller, but it does have a high-gloss black surround with an M logo placed on its horizontally arranged bars. Matching high-gloss black pieces on the front apron and rear trapezoidal exhaust tips tie it all together, much like the rug in The Dude’s apartment. If that’s not enough black, there’s also an M Carbon Exterior Package which adds carbon mirrors, intake inserts, and a rear spoiler.

Wrapping up the exterior changes, two new color options are available—Cape York Green metallic and Vegas Red metallic—and two new 19-inch Y-spoke wheels are available, named style 995M and style 1038i.

Moving to the interior, sport seats are standard. New steering wheel designs can be seen in both the lower-trim 430i and top-of-the-line M440i—the base update being a “sports steering wheel with a polygonal rim and two spokes” where the M Sport Package unlocks a three-spoke flat-bottomed wheel wrapped in M leather. The M Sport wheel comes with a cherry on top—literally a red stripe at the 12:00 position.

The large BMW Curved Display now runs iDrive 8.5 with a plethora of improvements. BMW reports, “Temperature, fan speed, and seat and steering wheel heating (when equipped) can now be adjusted by touch via the BMW Curved Display or by voice command with the help of the BMW Intelligent Personal Assistant. New adjustment controls for the air vent grilles in the center of the instrument panel and on the driver’s and front passenger’s side of the cockpit allow the direction of airflow to be adjusted using rotating and tilting movements.”

Worldwide launch of the new 4 Series is just a month away. If you’re looking to reinvent yourself for the summer of 2024 with a new 2025 4 Series, MSRP (not including $995 destination and handling) is as follows:

—Mike Bevels

[Photos courtesy of BMW.]