A year after eliminating the entry-level, 542-horsepower DBX and retaining only the 697-horsepower DBX 707, Aston Martin is adding the DBX S, an even more powerful version that boosts the twin-turbo 4.0-litre V8 to 717 horsepower. The nine-speed automatic transmission delivers quicker shifts in Sport and Sport+ modes, while the exhaust system has been reworked. This mean British SUV also benefits from reduced weight and revised steering.