Challenger is the most powerful muscle car ever. The Challenger SXT, with its standard powerful and fuel-efficient Pentastar V6 engine and TorqueFlite eight-speed transmission, delivers 305 horsepower and an estimated 30 mpg on the highway. The Challenger R/T with the high-torque 5.7-liter HEMI paired with the TorqueFlite eight-speed or six-speed manual transmission delivers up to 375 horsepower. The 392 HEMI delivers 485 horsepower and 475 lb.-ft. of torque: the most horsepower and torque available for a U.S. car. New for 2017, Dodge brings back the Challenger T/A to the naturally aspirated Dodge 5.7- and 392 HEMI lineup.