Dear Automation,
I don’t know if this would be possible, but I thought of the idea of a VR6 engine. Volkswagen uses these, and are more compact than a “normal V6” engine because the angle of which the pistons are facing is narrower than a “normal V6.” The “VR” in the name means something along the lines of, “Inline V6.”
The advantages of this setup would be that it’s more balanced than an I6, it can “get away” with a single valve train, has a higher displacement than a I4, and the exhaust comes out of only one side of the engine. The disadvantages of this setup would be that it costs more than an I4, is heavier than an I4, the engine is more complex but has less moving parts than an I6, and a restricted bore size.
I understand if this cannot be done at all, if not later in the games release or development, I just thought it’d be an interesting addition to the engine selection. 