For the first time ever, BMW is going to launch an all-electric M3, but it’s also going to give us a new combustion M3, and a new spy video reveals how it will sound. While the automaker has not confirmed exactly what will appear under the hood of this M3, it has said that it will be a “new type of six-cylinder engine” that won’t be part of a plug-in hybrid setup, and the new clip confirms that it will have an angry exhaust note, particularly when performing a cold start. The video, embedded at the bottom of this article, also has some drive-by footage, but several other BMWs were leading and chasing the M3 prototype, so there’s too much tire roar to hear what the new power plant sounds like under load.
First Mild-Hybrid BMW M3 Sounds Angry
Autoblog/SH Proshots
The new M3 sounds very similar to the existing one, which is powered by the S58 3.0-liter twin-turbocharged inline-six. Thus, while BMW may well designate the new engine with a new code, it’s likely to be an evolution of the same recipe. To help keep it emissions-legal in Europe, the mill is expected to adopt pre-chamber ignition, which BMW calls “M Ignite” technology. Pre-chamber ignition systems add a separate spark plug to a small area within the cylinder head, effectively pre-burning most of the air-fuel mixture before it reaches the traditional combustion chamber above the piston. Overflow openings in this pre-chamber send the partly spent mixture out into the main combustion chamber, where the traditional spark plug completes the ignition process, and this results in a cleaner, more complete burn that uses more of the air-fuel mixture’s total potential energy.
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According to BMW M, its system works as normal at low and medium revs, with the conventional spark plug firing in the main combustion chamber. This means the new engine should sound similar to the current S58 until it gets pushed (though the increasing dulling of exhaust systems to meet noise limits may have an impact). At higher revs and loads, the pre-chamber ignition system becomes the primary source of fuel ignition, maximizing the force produced during combustion, and BMW says “the flames generated as a result […] exit the pre-chamber at around the speed of sound.”
Final Thoughts
With sightings of M3 mules becoming more and more frequent, BMW appears to be close to wrapping up most of its development. However, with the current G80 M3 remaining on sale for next year, the next-generation G84 will be a 2028 model, and that means a reveal won’t happen until we’re at least a few months into 2027, if not a few quarters. We know it’ll have M Vision Neue Klasse-inspired styling, but we don’t know how much power will be on tap. That said, both AMG and Audi Sport offer north of 600 horsepower from their latest C 63 and RS 5, respectively, so it seems logical for BMW to continue stoking the flames of competition with something that plays in the same ballpark. We’ll bring you more info as soon as we get it.
