It's seems a pretty unfair contest, nonetheless, the guys from Autocar wanted to demonstrate how well the big 911 Turbo performed in terms of being clean. To make the contest more unfair/fair, the Peugeot will tour the track near it's maximum threshold whilst the trailing 911 will only be driven hard enough to keep up with the Pug.
Interestingly, the 911 Turbo is, according to the report, one of the most fuel efficient and environmentally friendly supercars available. It also offers a great power-to-CO2 emission ratio, emitting 272 grams of CO2 per kilometre.
Since the Turbo produces 368kW of power, it actually produces less CO2 per kilowatt than a 2010 Holden Commodore Omega 3.0-litre SIDI V6 engine. The 3.0-litre V6 offers 190kW of power and emits 221gm of CO2/km, equaling 1.16gm of CO2 per kilowatt. The Porsche? 0.73gm of CO2 per kilowatt.
Anyway, we don't want to spoil the the results too much. What will say though is it ends up being pretty close. Take a look.