Earlier quoted context omitted.
Their fuel consumption is about the same, what externalities are you referring to?
Sure, if you're talking about high-power cars (M2, Corvette, etc). A Miata or Civic Type R will get far better fuel consumption. And there's also wear on the road, noise, and damage to property and people when accidents happen (physics is a bitch).
I think more sports cars are burning out, revving loudly (or getting modified to take out their mufflers), and the damage from going a lot faster creates more damage.