2025 BMW 4-Series Adds 48-Volt Mild Hybrid Power

While we’ve only just flipped the calendars to 2024, in the automotive world 2025 is already upon us, as we see with BMW’s introduction of refreshed 4-Series coupes and convertibles for the 2025 model year.

A new 48-volt hybrid electric system replaces the previous unsatisfactory 12-volt engine stop/start system with a belt-drive mild hybrid that now contributes 11 horsepower to the total output of 386 hp for the 6-cylinder TwinPower Turbo engine and 255 hp for the 4-cylinder TwinPower Turbo. The 4-cylinder motor employs a more efficient Miller combustion cycle in place of the normal Otto cycle.

You can identify these new models by some mild tweaks to their sheetmetal compared to the 2024 models, but it might be easier to spot them by the changes to their lighting. The new LED headlights have been redesigned and have a new internal structure that lets them generate both high beam and low from a single LED module in the light, much the way conventional incandescent headlights could produce both high and low beams from one bulb.

Around back, look for new Laserlight taillights, which feature laser diodes that illuminate fiber optic glass bundles to produce 3-dimensional light graphics.

Inside, BMW has upgraded to BMW Operating System 8.5, and with it a new version of the company’s iDrive infotainment interface. There’s a new home screen and what BMW describes as “QuickSelect rapid access tech” that introduces a streamlined menu structure that borrows from the interfaces in consumer electronics devices.

This brings the ability to do things like selecting functions from persistently visible widgets on the home screen rather than having to navigate through a sub-menu. The company has apparently realized that a flat menu structure makes it easier to activate desired functions, so better late than never.

A new single-LED module produces both high beams and low beams. BMW

One of those functions is navigation, and for the 2025 4-Series, BMW has made it easier to input destinations and has added the Augmented View function. This feature supplements the navigation system’s map display with a live video stream overlayed with augmented reality information, such as a directional arrow pointing out turns.

With the new 4-Series coupe and convertible comes refreshed versions of their high-performance editions, the M4 coupe and convertible. The M4 gains all of the other new features and adds a more powerful drivetrain.
Or, actually, one of three more powerful drivetrains, depending on which exact configuration the driver wants. The basic M4 gets a 473-hp version of the 3.0-liter twin-turbocharged inline 6-cylinder engine driving the rear wheels through a traditional H-pattern 6-speed manual transmission with a clutch pedal.

A curved display and flatter menu system for BMW's iDrive welcome drivers in the 2025 4-Series. BMW

The M4 Competition Coupe’s powertrain features a 503-hp version of the engine, driving the rear wheels through an 8-speed M Steptronic automated dual-clutch transmission. And the M4 Competition xDrive has a 523-hp version of the engine powering all four wheels through the M Steptronic automated transmission.

BMW says that while the M4 is electronically speed limited to a top speed of 155 mph if that’s insufficient for your commute to work, you can pay them more money for the optional M Driver’s Package to increase the convertible’s top speed to 174 mph and the coupe’s top speed to 180 mph. The challenge for buyers would be to identify a road race track anywhere in North America where the car could reach such speeds on a track day.

BMW says it will start delivering all versions of the new 4-Series in March.