BMW’s most affordable M performance cars are arguably best known – at least in their current generation – for their potent twin-turbo six-cylinder engines, often regarded as some of the best in class.
A cloud has hung over the head of the ‘S58’ 3.0-litre straight-six which powers the M2, M3 and M4 though, due to upcoming emissions regulations which have threatened to see the models electrified.
To ensure the S58 can meet the upcoming ‘Euro 7’ emissions standards (due to be in effect from November 2026, BMW has announced the M2, M3 and M4 are soon to adopt a new pre-chamber ignition system, claimed to not only lead to lower emissions but also reduced fuel consumption under high loads.
Dubbed ‘BMW M Ignite’ technology, the new system centres around the pre-chamber positioned within the cylinder head, which is connected with the cylinder’s main combustion chamber by overflow openings.
This pre-chamber has its own spark plug and ignition coil, meaning the engine has two ignition systems.
While BMW says it patented the technology in 2024, we’ve seen an almost identical system feature on Maserati’s Nettuno V6 with the same benefits, while pre-chamber combustion was introduced in Formula 1 back in 2014, though it can be traced back to diesel engines.
“At low and medium revs, the conventional spark plug in the main combustion chamber fires before the spark plug in the pre-chamber,” BMW said in a press release.
“But when the engine is operating under higher revs and loads, the pre-chamber ignition takes over the lead role, with part of the fuel-air mixture channelled through the openings into the pre-chamber also ignited there.
“The flames generated as a result exit the pre-chamber at around the speed of sound.
“These ignition jets then ignite the mixture in the main combustion chamber above the piston at multiple points at the same time. The result is a significantly higher combustion speed.
“Meanwhile, the possible cause of uncontrolled combustion – i.e. “knocking” – is also countered effectively. An additional effect of this technology is a drop in the temperature of the exhaust gas.”
In addition to the new pre-chamber ignition system, BMW’s S58 will get a higher compression ratio and turbochargers with variable turbine geometry.
BMW is set to roll out the new system in the M3 and M4 from July 2026, meanwhile the M2 will get the technology from August.
There will be no additional outputs from the S58 engine in the three models, with the technology centred around better efficiency rather than performance.
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