Porsche continues to introduce new 911 variants for 2015, he latest of which are the Targa 4 and Targa 4S. The current 911 is based on the updated 991 platform that debuted with the Carrera and Carrera S in 2012. Several engines are available for 2015. In the Carrera, arrera 4 and Targa 4, uyers get a 3.4L horizontally-opposed direct-injected 6-cylinder that makes 350 horsepower. Carrera S, arrera 4S and Targa 4S buyers get a slightly larger 3.8L flat-6, hich makes 400 horsepower. The 50th Anniversary Edition, he GT3, he Turbo and the Turbo S all use different versions of this same 3.8L engine, aking different power in each variant. In the 50th Anniversary Edition, he engine makes 430 horsepower, hile in the GT3 it makes 475 horsepower. The addition of two turbochargers brings horsepower up to 520 and 560 for the Turbo and Turbo S, espectively.All engines are mated to a standard 7-speed manual transmission. The 7-speed PDK double-clutch automatic is optional, nd standard on the Turbo S. In the manual, he ratios are close together in every gear except 7th, hich helps to achieve a better fuel consumption rate during highway use. Other features include electric power steering and a hydraulic decoupler of the front and rear sway bars, nown as Porsche Dynamic Chassis Control. In addition, 11s feature a rear-wheel torque vectoring system that helps build traction using the rear brakes in conjunction with the rear differential.Inside, he 911 interior features styling touches consistent with Porsche's Panamera and Cayenne. There's no mistaking the design as anything other than 911, owever, ith a host of gauges flanking a large tachometer, ounted front and center. The center console sports a large color touchscreen monitor for navigation and stereo functions. Overall, he 911 strikes a good balance between being a focused sports car and a luxurious cruiser, ever feeling too hardcore to keep its occupants comfortable. Several packages add features such as special sports seating, ose audio, mbient lighting, uto dimming mirrors and more. The Sport Chrono Package includes dynamic engine mounts, dash-mounted analog and digital stopwatch, erformance display, Sport Plus button to control engine mapping and throttle response and launch control for cars equipped with PDK.