The same reason for using active exhaust valves... Agaist fatter cars came fatter torque curves. (evo.co.uk)
The GS has the same output, albeit with a slightly fatter torque curve, and thus relies on its host of suspension and appearance upgrades to justify its $ 6215 premium. (automobilemag.com)
That may not seem like much more, but the turbocharged power delivery offers a far fatter torque curve, especially in the mid-range. (carbuzz.com)