‘X166’-series Mercedes GLS is a full-size luxury SUV during 2016-2020. If you need a 7-seat SUV equipped with a comfortable and spacious interior room, you could add it to your wish list. To support such a giant wagon, the factory rims are 19’’ to lift the weight that is 240kgs heavier than its rival Range Rover. Many X166 owners will choose to purchase bigger wheels to satisfy the need off-road. If you’re not quite familiar with the wheel spacers, you must worry about their safety. Let’s make some distinctions.

How Big of a Benz X166 Wheel Spacer is Safe?

If you cannot decide what size of Mercedes GLS X166 wheel spacers is suitable, check it on your user manual. The PCD (Pitch Center Diameter), CB (Center Bore), thread type, fastening, and the specified torque are all given on the manual. The closer the spacer is customized to the original vehicle axle specs, the safer it will be.

The thickness of 2017 Benz X166 wheel spacers is another aspect. The thickness should also be controlled in a certain range to promise safety. Generally, the thickness of 2017 Benz GLS X166 wheel spacers is measured by the horizontal distance between the fender edge and tire edge. The thickness below this value is safer. As for the minimum, it’s not recommended to be less than 5mm because too-thin adapters cannot be designed to be hub-centric. The lack of hub-centric design will easily lead to vibration issues.


Can You Put X166 Wheel Spacers on the Back/Rear Only?

No problem at all. But you must make sure the two wheels are fitted with the same-thickness wheel spacers. For example, you could install 15mm wheel spacers on your front wheels at the same time. Only in this way your vehicle alignment can be balanced. The improper use of different thickness Mercedes X166 wheel spacers will lead to severe damage on your bearings, control arms, and suspensions as time goes by.

However, if you pursue performance enhancement on-road or off-road, you’d better place 4 pieces of wheel spacers on each of your Benz GLS X166. The thickness of the front spacers is different from the rear spacers because the axle design and specs are different. Generally, wheel spacers on the rear wheels are thicker than the front ones.

As long as you purchase the high-quality forged hub-centric wheel spacers and install them correctly, they’re not only safe but also improve the safety of other components and the whole vehicle system. If you’re thinking of changing bigger wheels for your Mercedes-Benz GLS X166, the wheel spacer is an ideal tool to help you avoid the rubbing issues against the wheel arch, and optimize the X166 stance as well.