With every automaker focused more and more on downsizing and with BMW’s fascination with 500cc cylinder size currently in full swing, most people assumed that a BMW M car powered by a 2-liter 4-cylinder mill would be only a matter of time. Rivals from Mercedes-AMG have done it already with the 45 AMG models in the CLA or A-Class models or even the GLA, but it looks like BMW is in no rush to do the same.
Speaking to the media on the sidelines of the Frankfurt Motor Show, the boss of the M division, Frank van Meele said that a 4-cylinder engine is not in the books at the moment or for the near future. Assuming the size of cylinders remains the same, a 2-liter high-performance mill from the Motorsport division seems like a distant dream. “We are really happy with our six-cylinder [engines] because for BMW and BMW M that is our heritage engine. We started with six-cylinder in the M1 so it has a long history. BMW is a six-cylinder inline company and, for us, it’s an iconic engine,” Van Meel said.
“If you look at it with a four-cylinder, I don’t see characteristics that I would like on an M car, on a small displacement turbocharged four-cylinder engine. I wouldn’t do a four-cylinder standalone turbocharged with high performance, because you always have the characteristic that if you want high performance you lose the low-end torque and you lose the overall driveability you want to have from the car,” he added for Car Advice.
However, some of these drawbacks might be compensated for by using a mild hybrid setup. Electrification of such mills could fill torque gaps at any revs and could make such a setup acceptable, as is the case on the BMW i8 for example, keeping the dimensions, of course. “Electrification would help because low-end torque is done with electric motors. On the other hand, you are putting a lot of weight into the car, so that answer is not so easy. To say ‘just do it’, you lose the motorsport topic of power-to-weight ratio which is very important with overall weight,” said Van Meele about such a possibility.
Therefore, unless the M and i engineers can find a perfect balance between weight and performance a 4-cylinder M model is not likely in the near future.