A 268-horsepower, 3.5-liter V-6 is standard. The engine moves the GLK350 rapidly when you want, and the seven-speed automatic transmission consistently shifts smoothly no matter if you're driving leisurely or aggressively. The transmission includes Comfort and Sport modes in addition to a clutchless-manual setting if you prefer to control shifts yourself.

The GLK350 can easily keep pace with fast highway traffic, and the V-6 still has some grunt left in it for high-speed acceleration, though not enough to take you aback. Downshifts are easy to induce by prodding the gas pedal.

It took me a little longer than normal to get used to the crossover's brakes. While there's an adjustment period when moving to any new vehicle as you adapt to its characteristics, the significant amount of brake pedal travel that's required to initiate strong braking in the GLK350 is outside the norm and took me by surprise when first driving it. The brakes have good linearity, which is something that's lacking in some of Mercedes' other models, but they'd be nicer if they were more responsive higher in the pedal's travel.