Photo of S550 plug-in hybrid courtesy of MBUSA.

Photo of S550 plug-in hybrid courtesy of MBUSA.

The 2016 Mercedes-Benz S550 plug-in hybrid luxury sedan will join the automaker's growing lineup of gasoline-electric hybrids and battery-electric vehicles when it arrives in April of 2015.

The S550 plug-in hybrid will become the fourth such vehicle offered by Mercedes-Benz in the U.S., following the E400 hybrid, smart electric drive, and B-Class Electric Drive. The B-Class arrived earlier this year.

The S550 plug-in hybrid pairs a gasoline V-6 producing 329 hp with an 85-kilowatt electric motor that generates 114 hp. That equates to a system output of 436 hp and 479 lb.-ft. of torque. The vehicle also gets a seven-speed automatic transmission.

Under European testing standards, the vehicle's plug-in electric powertrain can is expected to reduce carbon-dioxide emissions by up to 43 percent over a comparable gasoline-powered version.