The 2017 Mercedes-Benz Trucks GLS550 sits in the modern full-size luxury SUV world, where high-speed road manners, substantial curb weight, and premium ride quality all place real importance on proper tire fitment. As a large, powerful 4Matic sport utility, it depends on a tire that matches both its stance and its chassis expectations. For this vehicle, the primary fitment is a 295/40R21 radial, giving the GLS550 a modern low-profile metric size on a 21-inch wheel. That makes the main decision less about multiple fitments and more about confirming the correct wheel setup, maintaining the proper overall look, and choosing a tire suited to the vehicle’s intended road use.
Which Tire Size Is Right for The 2017 Mercedes-Benz Trucks GLS550
The 2017 Mercedes-Benz Trucks GLS550 uses one primary tire size: 295/40R21, a radial fitment on a 21-inch rim. The GLS550 4Matic uses this same size, so the key step is confirming that the vehicle still has the correct wheel diameter and comparable wheel width before selecting a tire for road use, replacement, or updated service.
A 295/40R21 size uses a modern metric radial format: 295 is the nominal section width in millimeters, 40 is the aspect ratio, R identifies radial construction, and 21 is the wheel diameter in inches. On the 2017 Mercedes-Benz Trucks GLS550, this size reflects a contemporary low-profile SUV fitment designed around a large-diameter wheel. The format matters because it ties sidewall height, wheel size, and overall proportions together more tightly than older tire sizing systems. Choosing this size starts with verifying that the GLS550 still has the proper 21-inch wheel setup and sufficient clearance for the exact tire being considered.
Fitment is straightforward across the covered 2017 Mercedes-Benz Trucks GLS550 sub-models. The shared tire size means the main concern is confirming that the vehicle still retains the correct 21-inch wheel setup rather than sorting through multiple factory tire-size combinations.
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2017 Mercedes-Benz Trucks GLS550 4Matic
The 2017 Mercedes-Benz Trucks GLS550 4Matic uses the 295/40R21 radial tire size. That keeps selection focused on confirming the wheel setup, checking overall tire condition, and choosing a replacement that suits the vehicle’s intended on-road use and maintained appearance.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Frequently Asked Questions
Common questions for the 2017 Mercedes-Benz Trucks GLS550 usually center on the 295/40R21 tire size, 21-inch rim fitment, replacement selection, and what to inspect before putting a heavy luxury SUV back into regular road use.
Tire Size & Fitment
What tire size fits a 2017 Mercedes-Benz Trucks GLS550?
The 2017 Mercedes-Benz Trucks GLS550 uses a 295/40R21 radial tire. That is the primary fitment for this model and matches a 21-inch wheel diameter, using a modern metric radial sizing format rather than an older numeric or alphanumeric system.
For a buyer, the practical step is confirming that the vehicle still has the correct 21-inch wheels and has not been changed to a different wheel-and-tire package. On a used GLS550, aftermarket wheels, alternate seasonal setups, or previous replacements can change what is currently on the vehicle, so the wheel diameter and overall clearance should be checked before choosing a replacement tire.
What size rim does a 2017 Mercedes-Benz Trucks GLS550 use?
The 2017 Mercedes-Benz Trucks GLS550 uses a 21-inch rim with its 295/40R21 tire size. In that size code, the final number, 21, identifies the wheel diameter in inches, which is the critical dimension for matching the tire to the wheel.
Rim diameter should be confirmed before anything else because a tire sized for a 21-inch wheel cannot be mounted on a different wheel diameter. It is also worth checking the actual wheel on the vehicle rather than assuming it is original, especially if the GLS550 has had previous owner modifications, seasonal wheel swaps, or replacement wheels fitted during its service life.
Does the 2017 Mercedes-Benz Trucks GLS550 4Matic use the same tire size?
Yes. The 2017 Mercedes-Benz Trucks GLS550 4Matic uses the same 295/40R21 radial tire size. That makes fitment simpler within the covered sub-model range because there is not a separate primary tire size to sort through for the 4Matic version.
Even with shared fitment, it still helps to verify the actual wheel-and-tire setup on the vehicle in front of you. A GLS550 that now wears non-original wheels or a different replacement package may no longer match the standard 21-inch arrangement, so confirming the installed wheel diameter and checking tire-to-suspension and tire-to-fender clearance remain worthwhile before replacement.
Choosing the Right Tire
What should I consider when choosing a 295/40R21 tire for a 2017 Mercedes-Benz Trucks GLS550?
Start with the correct size, which for this vehicle is 295/40R21, and make sure the tire is intended for a 21-inch wheel. Because the GLS550 is a large luxury SUV, the buyer should also pay attention to overall tire condition, construction consistency across the set, and whether the vehicle will be used mostly for highway driving, local road use, or occasional extended trips.
Wheel setup matters just as much as size code. A used GLS550 may have replacement wheels with different width or offset, and those changes can affect how a tire sits in the wheel opening and how much clearance remains at steering and suspension points. Matching the installed setup before purchase helps avoid appearance mismatches and fitment surprises.
How do I choose between replacement tires for a 2017 Mercedes-Benz Trucks GLS550?
The first filter is simple: stay with the correct 295/40R21 size and a radial construction suitable for the GLS550’s 21-inch wheel. After that, the meaningful comparison points are the tire’s intended use, its overall condition if the vehicle is a low-mile collector or secondary-use SUV, and whether the tire maintains the look and road manners expected from a premium full-size model.
A smart comparison also includes the actual vehicle setup. A GLS550 with stock-style wheels may call for a different approach than one with altered suspension height or aftermarket wheels. Choosing carefully means balancing proper size, wheel compatibility, ride expectations, and visual proportion instead of treating every 295/40R21 tire as identical in application.
What rim-fitment details should I compare when choosing tires for a 2017 Mercedes-Benz Trucks GLS550?
The most important rim-fitment detail is the 21-inch wheel diameter required by the 295/40R21 size. After that, the buyer should confirm the actual wheel dimensions and setup on the vehicle, since wheel width and offset can influence how the tire sits and whether the overall package remains properly centered within the fender and suspension space.
This matters most on a modern SUV with a wide, low-profile tire. Small differences in wheel setup can change sidewall shape, inner clearance, and outer fender position even when the size code stays the same. Confirming the existing wheel arrangement before purchase helps keep the replacement tire aligned with the GLS550’s appearance and usable road clearance.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2017 Mercedes-Benz Trucks GLS550?
Yes. Modifications can affect tire fitment on a 2017 Mercedes-Benz Trucks GLS550 even when the original tire size is 295/40R21. Aftermarket wheels, altered wheel offset, suspension changes, lowering, or body modifications can all change how much room the tire has at the fender, steering components, and suspension points.
That is why the actual vehicle should be checked before replacing tires, especially on a pre-owned SUV. A GLS550 that no longer uses its original-style wheel setup may need more careful measurement and inspection before another 295/40R21 tire is selected. Clearance at full steering lock and through suspension movement is especially worth confirming.
What should I inspect before driving a 2017 Mercedes-Benz Trucks GLS550 on new tires?
Before road use, inspect the wheels for damage, confirm the tire size matches the vehicle’s setup, and check that each tire is seated correctly and inflated appropriately for service. It is also wise to look over the suspension and steering for worn parts that could affect how the new tires track, wear, or clear surrounding components.
A short visual inspection can prevent bigger problems later. Look for rubbing marks inside the wheel opening, uneven old tire wear that may point to alignment issues, and any signs of air loss after installation. On a heavy luxury SUV like the GLS550, sound suspension condition and proper inflation play a major role in getting stable, predictable road behavior.
How often should tires on a 2017 Mercedes-Benz Trucks GLS550 be inspected?
Tires on a 2017 Mercedes-Benz Trucks GLS550 should be inspected regularly, not just when replacement time arrives. Monthly pressure checks are a practical baseline, and visual inspections for cracking, punctures, bulges, irregular wear, and curb damage should also be part of routine ownership, especially if the vehicle sees mixed use or long periods of sitting.
Inspection becomes even more important before a longer drive. A GLS550 can mask tire issues until speed, heat, or load bring them out, so checking tread condition, sidewalls, and air retention before road trips is time well spent. Vehicles stored for stretches should also be examined for age-related deterioration and flat-spotting before normal use resumes.
