Tbh, if the precise variants being compared are all in the same ball park, then to me, it doesn't really matter
My question essentially has two purposes:
1) Understand if an engine swap to a 710 or C175 would have a noticeable impact on general emissions
2) further my understanding on which engines are theoretically best for applications
But as illuded to before, if the variants and their marginal differences alter whats considered the most eco friendly, then I doubt there's much in it between em