* 2.4L Ecotec I4: This was the base engine.
* 2.0L Turbo I4: A more powerful turbocharged four-cylinder engine. This was often the more common engine choice in higher trims.
* 3.6L V6: A V6 engine was available, usually in higher trim levels like the GS.
Therefore, there isn't one single engine size. The specific engine depends on the trim level of the 2014 Buick Regal.
