The M2, M3, and M4 are all picking up a new pre-chamber combustion system that improves efficiency under heavy use, and also helps them meet new emissions standards. The S58 inline-6 engine in the BMW M2, M3, and M4 has been around for more than a decade, but it still puts out enough power with enough efficiency to stay relevant on the modern performance car market.
Now, thanks to a new pre-chamber combustion technology being introduced to all three models this summer, it should survive well into the next era of European emission compliance rules. Drivers who track their M cars should see a notable gain in efficiency, too. BMW calls the new technology "M Ignite," but it is best understood as a handy new device within the car's cylinder head.
View Price on AmazonThe new pre-chamber contains its own spark plug and ignition coil, connected to the main combustion chamber through overflow openings. It takes a back seat to the conventional spark plug and ignition coil at low and medium revs, but at higher revs, some fuel-air mixture is sent through openings into the pre-chamber for ignition. This, in turn, ignites the main combustion chamber from multiple points.
BMW says that this should both lead to a "significantly higher combustion speed" and counters a "possible cause of uncontrolled combustion." When paired with a new higher compression ratio and new variable turbine geometry for turbochargers, the company claims that the new system "boosts the efficiency of the six-cylinder in-line engines dramatically, especially when the engine is being pushed to its limits."
For those who track their M cars, that should mean serious benefits in on-track efficiency. Buyers expecting more power will be disappointed, though; the company claims that both displacement and power are unchanged from the previous iteration of the S58. This system also gets the S58 in line with strict new Euro 7 emission standards that go into effect in November.
Source: roadandtrack.com
