On this YouTube finds, we have the 2.0 engine. A video courtesy of Drive Tribe, in which they explain why the 2.0 engine is the most common and the mathematical relation between each cylinder capacity in modern engines.
There are very interesting mathematical observations in this video, on certain commonalities across engines and their cylinder capacity. Although, not everything is black and white, this gives you more clarity about engines and why manufacturers choose certain engines.
Again, keeping this post short and sweet, I leave you with the video, enjoy!!
DL