Comparing engines

Today I came to the realization that in order to truly asses which car has the highest performing engine, I must first understand which factors within the machinery are most relevant to its performance. Coincidentally, I had to understand how a motor functions, with this knowledge I was able to select the four main categories that I will be comparing within the magazine.

  

This is what I came up with:

1)Net power output

2)Weight/size

3)Efficiency

4)materials/durability/pricing

I will conduct individual research on each of the two engines and include a detailed comparison between the C63 & M3.