sentences:  The SS with manual transmission is powered by the 6.2 L () GM LS3 V8 engine rated at at 5,900 rpm and of torque at 4,600 rpm while the SS with automatic transmission is powered by a new variant of the LS3 called the GM L99 which produces at 5,900 rpm and of torque at 4,300 rpm.The L99 V8 engine, not to be confused with the earlier LT-series L99, uses Active Fuel Management which enables the engine to run on only four cylinders during urban driving conditions, such as highway cruising, to improve fuel economy.Other features include a fully independent four-wheel suspension system, variable-rate power steering, four-wheel disc brakes standard on all models (four-piston Brembo calipers on SS models), a StabiliTrak electronic stability/traction control system, Competitive/Sport modes for the stability system offered on SS models, launch control on SS models equipped with the six-speed manual transmission, and 6 standard air bags that include head curtain side-impact air bags and front seat-mounted thorax side air bags.