888-906-9328 The standard engine on the 2012 Chevy Sonic is a 1.8-liter inline-4 that makes 138 hp and 125 lb-ft of torque. LT and LTZ models are available with a turbocharged 1.4-liter inline-4 that generates 138 hp and 148 lb-ft of torque. A five-speed manual transmission is standard with the 1.8 liter, with a six-speed automatic available as an option. A six-speed manual transmission is standard with the turbocharged 1.4, and it's the only transmission available with this engine. EPA fuel economy estimates stand at 26 mpg city35 mpg highway and 29 mpg combined for the 1.8-liter engine with the manual transmission, with the engine getting 253528 with the automatic. Chevy's estimates place the turbocharged 1.4-liter at 2940.