Well, yes, the higher the number of cylinders, the higher the losses, more bearings, valves and followers. A 2x small pistons will have a greater circumference then a single bigger cylinder (of the same displacement), that means there's more surface area to run on the cylinder walls creating more friction. Think of a rubic's cube. How many faces would there be if each block was a separate cylinder?* Now think about how many faces are hidden when combined into a full cube?*
Most car 1.0's are 3 cylinders for a reason. My Fiat's a 2 cylinder
Maybe they'll go the Mustang route of a turbo 4?
*Answers: 162 vs 54 Ok, the tops and bottoms don't add friction, but you get the idea.