The Korean firm’s rugged seven-seat SUV retains a 2.2-litre diesel engine, but its maximum output has been raised from 178bhp to 199bhp and its torque increased from 310lb ft to 324lb ft.
Ssangyong says the system is tuned to deliver strong low-end torque, resulting in a 0-62mph time of 11.9sec.
The revised engine is twinned with a new eight-speed automatic gearbox, produced by Hyundai Transys, which Ssangyong claims reduces weight and vibrations while improving efficiency.
The Rexton retains a selectable four-wheel drive system that includes high and low-ratio modes and off-road settings.
The car can achieve 32.2mpg on the WLTP combined cycle, with official CO2 emissions of 225g/km. It also has a towing capacity of 3500kg and has gained a new Trailer Sway Control feature to improve towing stability.
In addition to the new powertrain, the Rexton has been given a makeover, with a revised front end featuring a new grille and LED headlights. The rear end has also been revised.
The Rexton will continue to be offered in two trim levels. Ventura replaces ELX, while the top-sped Ultimate adds 18in alloy wheels, a 9.0in infotainment touchscreen, heated seats and other upgrades.
The Ventura starts from £37,995 and the Ultimate from £40,665.