Why would engine designers opt to include more cylinders in an engine instead of increasing the displacement?

Question

For example, why would a car manufacturer opt to to use a 2.0L in line six instead of a 2.0L in line four in a vehicle. Are the benefits of including more cylinders in an engine worth the added complexity?

In: Engineering

Answer 1

There are really good answers here. I think the answer is sometimes as simple as what the manufacturer already has on hand for engine technology.