The fifth-generation Kia Optima was revealed to the global market as the Kia K5, which is rumored to become the car's new name. But even though we got to see the car's design, Kia kept silent on what would be used under the hood... until now. Kia has revealed a range of new 'Smartstream' powertrains which, for the first time ever on an Optima, include all-wheel-drive. This is a significant addition to the Optima that will help it compete with other AWD models in the mid-size segment like the Nissan Altima and Subaru Legacy. It is also an intriguing addition because the Optima's corporate cousin, the Hyundai Sonata, only comes with front-wheel-drive.

Kia says the North American and Korean market cars will be powered by a 1.6-liter T-GDi (turbocharged gasoline direct injection) engine. It will produce 180 ps at 5,500 rpm and 265 Nm of torque between 1,500-4,500 rpm, which translates to around 177 horsepower and 195 lb-ft of torque. These numbers are nearly identical to those found in the Sonata with the same power unit. Some markets (likely not North America) will get a 2.0-liter engine while we will likely receive a 2.5-liter four-cylinder as the base mill, producing 191 hp and 181 lb-ft of torque, as it does in the Sonata.

As we expected, there will also be a sportier Optima GT trim with a turbocharged 2.5-liter engine. Kia says the GT will produce around 290 hp and 311 lb-ft of torque, which is identical to the recently-teased Sonata N-Line. The 0-62 mph time is estimated at around 6.6 seconds but there is no word on if the GT will also receive AWD, or if it will be FWD like the Sonata N-Line. Base engine cars should get an eight-speed automatic while the turbocharged models will get Kia's new eight-speed dual-clutch.

As with the last-generation model, Kia says hybrid variants will also be available. There is no official word on pricing or when we will see the US-market car revealed.