We need a new Yardstick for Supercars

For centuries the benchmark for Supercars was acceleration from 0-100 km/h or horsepower to weight ratio. Given today's problems with mother earth and more and more restrictions on public roads we probably should think about a new way to measure Supercars. Here's what I propose:
Let's take kg/PS (weight to horsepower) and CO2 g/km and build an index, called SCPI (supercar performance index) based on these two standard measures. Cars that score well, have both a low weight at high engine performance and low fuel consumption at the same time. It's no surprise that light cars do better. The winner here is the KTM X-Bow. I agree that this is a very "basic" car and probably not more than a toy. Number 2 is already more usable and can even be driven every day. The Artega brings everything you need for both track and traffic jam. And on place 4 we have a Porsche which seems to make sense too. None of the usual suspects in the supercar field though makes the top of the list. It's because these cars are way too heavy and therefore are quite inefficient in terms of fuel consumption.