BMW’s 3-Series has long been known for its silky-smooth inline-six engines. In these fuel-conscious times, however, the Munich-based automaker is replacing some of its inline-six engines with 2.0-liter, turbocharged four-cylinder powerplants in 3-Series and Z4 models.

If Britain’s Whatcar? is correct, the downsizing won’t end there, either. BMW’s head of engine development, Peter Nefischer, has stated that the automaker is working on three-cylinder engines for various applications, including some that could make it to the next 3-Series models.

From Nefischer’s perspective, current engine technology has matured almost as far as it can go, which means that the next step is downsizing to save weight and boost fuel economy. In his words, “Downsizing will go further, with smaller, more powerful engines.”

While three cylinder engines are nothing new, using them for applications as large as the 3-Series is. There’s also the issue of prestige to think about, as BMW buyers have certain expectations for performance and luxury, which won’t be met by an under-sized (and potentially underpowered) engine.

Given the overall trend of engine downsizing, we’d say it’s just a matter of time before three-cylinder engines become as common as four-cylinder engines are today. The only real question remaining is which automaker will introduce them first.