BMW M’s six-cylinder petrol engine saved. Here’s how the S58 will beat emissions regulations
The BMW M six-cylinder will live on, with unchanged power outputs but emissions reduced enough to make it Euro 7 compliant. Here’s how.
Euro 7 emissions regulations loom, with all car manufacturers who wish to ply their trade in Europe needing to bring their combustion-engined models in-line by the end of November this year. BMW M’s been making changes, first recalibrating the M5’s combustion engine and hybrid system to reduce its emissions output. Now it’s the turn of the S58 twin-turbo straight-six. Yes, it’s set to survive Euro 7 but it’s not been the work of a remap.
Instead, BMW M has moved to implement a new combustion system, with pre-chamber ignition tech that it calls M Ignite. The system is not unlike that used in Maserati’s MCPura-powering Nettuno V6. It’s a concept whose efficiency, performance and reliability has been proven in F1.
As a reminder, pre-chamber combustion technology uses a small explosion to ignite the fuel rather than a traditional spark at high loads, giving ignition that’s quicker and more evenly spread across the combustion chamber. This means you need less fuel for the same power output, which therefore reduces consumption and emissions. It also reduces the chances of uncontrolled ignition or knock.
BMW claims that fuel consumption under high loads has been ‘reduced substantially’, saying the effects will be noticeable for trackday goers when driving hard for extended periods. The engine still features conventional spark plugs, for consistent and smooth running under lower loads, in normal road use.
Exact numbers in terms of CO2 g/km outputs have yet to be published but for reference, the current M3 Competition xDrive produces up to 230g/km of CO2, according to WLTP-standard testing. Power and torque figures, as well as displacements aren’t set to change, meaning the M3 and M4 will still have 2993cc engines and should be good for their current 503bhp and 479lb ft outputs.
The M3 and M4 are set to receive the new system from July 2026. All M2 variants will get the engine from August 2026.
