BMW M’s signature straight-six and V8 engines will survive the introduction of the tougher Euro 7 emissions regulations – and, the division’s boss claims, with no loss of performance.

Although the emissions levels allowed for cars are unchanged from the current Euro 6e regulations, they will be tested over a broader (and harder) range of scenarios said to better reflect real-world driving. They must also remain compliant for 10 years or 124,000 miles, twice as long as currently. Brake and tyre emissions will also be monitored for the first time.

Speaking to Autocar at the Goodwood Festival of Speed, BMW M CEO Frank van Meel said “the challenge was not so much to make an engine that is EU7 compliant”, but to “keep performance”. 

He explained: “The whole story is about driving with lambda one [when the air-fuel ratio for combustion is perfectly matched] so you have to keep that, and there's no cooling. Normally, if you are in high-performance situations, you cool using the fuel. With EU7, that’s impossible, so you need to find different ways of avoiding temperature build-up.

“The combustion process has to be improved in regards to heat build-up and also the cooling, and those are the challenges. Of course you can [reduce] performance to avoid this temperature increase, but you don’t want to – that’s where we started. The new balance of performance is that we drive lambda one, but we don’t want to lose performance.”

Van Meel would not be drawn on how M has reworked the engines to achieve this, saying only that it has made some “very interesting” tweaks that it will discuss in detail in due course.

“The six-cylinder in-line engine is our legacy, and the V8 has got a long history in racing, so we intend to keep going,” said Van Meel.

Asked whether M would consider downsizing to three- or four-cylinder powerplants with increased electrification to reduce emissions, he simply replied: “No.”

He added that such engines cannot meet M’s “very specific mindset” for how it wants performance cars to drive, with regard to torque delivery, rev ranges and the weight of its models. “I couldn’t imagine putting a four-cylinder in an M5,” he said.