The AGILITY CONTROL suspension on which the Mercedes-Benz GLK-Class is founded displays a high level of flexibility and resolves a conflict of aims that particularly affects the SUV class, where chassis engineers want to create a vehicle that is both sportily agile and comfortably smooth yet one which can also cope with off-road terrain. If the focus is on sporty, active handling, the suspension and, above all, the shock absorbers need to display a certain firmness, which precludes access to the brand's typical suspension comfort and limits the off-road options. If the vehicle is set up with softer dampers to ensure suspension comfort and off-road capability, dynamic handling naturally suffers. The solution is "amplitude-dependent damping". In this system, the damping forces of the shock absorbers are configured to respond flexibly rather than lineally. In normal driving mode on moderately contoured roads or during slow off-road manoeuvres, the system responds softly, enhancing both the occupants' comfort and the vehicle's off-road capability. To ensure that this level of comfort is maintained when driving hard or performing abrupt evasive manoeuvres, in these situations the dampers deliver a harder performance, ensuring optimum handling stability. At the same time, the driver of the GLK is supported by speed-sensitive power steering, specified as standard for the V6 models, which provides the optimum level of steering assistance for the situation in hand. Parking and off-road manoeuvring are made much easier because maximum power assistance is available. At higher speeds, the assistance is reduced in favour of greater handling stability.

All the base models in the GLK series are fitted with 17-inch, size 235/60 R 17 light-alloy wheels. In conjunction with the exterior sports package, which is included as standard when the car first comes onto the market, or the off-road styling package, all models are shod with mixed-size tyres which, together with the AGILITY CONTROL suspension and the asymmetric power distribution between the front and rear axle, form the basis for a even better transfer of power between the wheels and the road. And the more effective this power transfer, the less frequently the electronic control systems need to intervene. The road-oriented exterior sports package features size 7.5 J x 19 light-alloy wheels with 235/50 R 19 tyres at the front and size 8.5 J x 19 wheels with 255/45 R 19 tyres at the rear. If the GLK is ordered with the off-road styling package, the front axle has size 7.5 J x 17 light-alloy wheels with 235/60 R 17 tyres, while the rear axle features size 8.0 J x 17 wheels with 255/55 R 17 tyres. All models are equipped with a TIREFIT system for repairing tyre damage. A compact spare wheel, which can be used on the front or rear axle, is available as an optional extra.