The 2015 Mercedes-Benz Trucks GL350 sits in the modern luxury SUV era, blending long-distance comfort, diesel-powered touring character, and the all-weather confidence expected from a 4Matic sport utility. For owners, the tire decision is less about vintage-style construction and more about matching the correct metric radial size to the wheel already on the vehicle. This GL350 uses either 275/55R19 or 275/50R20 radial tires, depending on the wheel setup. That makes wheel diameter the first thing to confirm before comparing tire choices. Once that is settled, the focus shifts to keeping the proper proportions, load capability, and clearance for everyday road use.
Which Tire Size Is Right for The 2015 Mercedes-Benz Trucks GL350
The 2015 Mercedes-Benz Trucks GL350 uses two primary tire sizes, and the right one depends on the wheel diameter on the vehicle. Both are metric radial fitments, but one is built for a 19-inch rim and the other for a 20-inch rim. Before choosing a tire, confirm whether the GL350 is wearing 19-inch or 20-inch wheels, especially if it has been changed from its original wheel setup.
275/50R20 is a modern metric radial size in which 275 is the nominal section width in millimeters, 50 is the aspect ratio, R identifies radial construction, and 20 is the rim diameter in inches. On the 2015 Mercedes-Benz Trucks GL350, this size is used with a 20-inch wheel and keeps the fitment in a contemporary SUV sizing format. Its dimensions make it very close in overall height to the 19-inch option, but it belongs only on the correct wheel diameter. This is the size to evaluate if the vehicle is equipped with factory-style or aftermarket 20-inch rims.
275/55R19 is a metric radial size with a 275-millimeter nominal section width, a 55-series aspect ratio, and a 19-inch rim diameter. For the 2015 Mercedes-Benz Trucks GL350, it serves the same general fitment role as the 20-inch option but is intended for a 19-inch wheel. The slightly taller profile relative to the rim is part of the size design, even though its overall diameter stays close to the 20-inch alternative. This size should be chosen only after confirming the wheel diameter and checking that the vehicle has not been altered with a different wheel and tire package.
Fitment is straightforward here because the covered sub-model uses the same two tire-size paths tied to wheel diameter. Checking the exact sub-model still helps, but confirming whether the vehicle has 19-inch or 20-inch wheels is the more important step before selecting tires.
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2015 Mercedes-Benz Trucks GL350 Bluetec 4Matic
The 2015 Mercedes-Benz Trucks GL350 Bluetec 4Matic uses radial tires in either of the two primary metric sizes, depending on the wheel package installed on the vehicle. That means tire selection starts with wheel confirmation, then moves to choosing a tire that preserves the intended proportions, clearance, and road-use suitability.
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 2015 Mercedes-Benz Trucks GL350 usually center on the correct tire size, 19-inch versus 20-inch rim fitment, and what to inspect before putting a luxury SUV with possible wheel-package changes back on the road.
Tire Size & Fitment
What tire size fits a 2015 Mercedes-Benz Trucks GL350?
The 2015 Mercedes-Benz Trucks GL350 uses one of two radial tire sizes: 275/55R19 or 275/50R20. Both sizes apply to the GL350 Bluetec 4Matic, and the correct choice depends on the wheel diameter installed on the vehicle rather than a separate tire-construction decision.
That makes wheel verification the first step before buying tires. A 19-inch wheel requires 275/55R19, while a 20-inch wheel requires 275/50R20. If the SUV has aftermarket wheels or a changed wheel-and-tire package, check the wheel size directly and make sure the selected tire maintains proper clearance at the fenders, steering components, and suspension.
What size rim does a 2015 Mercedes-Benz Trucks GL350 use?
A 2015 Mercedes-Benz Trucks GL350 uses either a 19-inch or 20-inch rim, depending on the tire size on the vehicle. The 275/55R19 tire is matched to a 19-inch rim, and the 275/50R20 tire is matched to a 20-inch rim.
The rim diameter cannot be mixed between those two tire sizes, so it should be confirmed before any replacement. Looking at the sidewall size is useful, but checking the wheel itself is smarter when the SUV may have had a wheel change. Once rim diameter is confirmed, compare the replacement tire's dimensions and intended use so the GL350 keeps the expected stance and clearance.
Why does the 2015 Mercedes-Benz Trucks GL350 have more than one tire size?
The 2015 Mercedes-Benz Trucks GL350 has more than one tire size because it was fitted with different wheel diameters. One setup uses 275/55R19 on a 19-inch rim, while another uses 275/50R20 on a 20-inch rim. Both are radial metric sizes intended for the same model line.
That does not mean the two tires can be chosen interchangeably without checking the wheel already on the vehicle. The real difference is wheel package, not just preference. Buyers replacing a full set should confirm the existing wheel diameter and inspect for prior changes such as aftermarket wheels, altered offsets, or suspension modifications that could affect clearance with the selected size.
Choosing the Right Tire
What should I consider when choosing a tire for a 2015 Mercedes-Benz Trucks GL350?
Start with the correct size for the wheel on the vehicle: 275/55R19 for a 19-inch rim or 275/50R20 for a 20-inch rim. Since both are radial metric fitments for the 2015 Mercedes-Benz Trucks GL350, the first priority is matching the tire to the actual wheel diameter and maintaining the intended overall proportions.
After size is confirmed, compare factors such as load suitability, tread design, and how the SUV is used. A GL350 that spends most of its time on highway trips may call for a different tire emphasis than one seeing more mixed driving. It is also worth checking wheel width, suspension condition, and any previous changes to the vehicle before making a final selection.
How do I choose between the available 275/55R19 and 275/50R20 tires for a 2015 Mercedes-Benz Trucks GL350?
The choice between 275/55R19 and 275/50R20 is not a matter of preference alone, because each size belongs to a different wheel diameter. A 2015 Mercedes-Benz Trucks GL350 with 19-inch wheels needs 275/55R19, while one with 20-inch wheels needs 275/50R20.
Once the wheel size is confirmed, compare replacement tires by intended driving use, construction details, and how closely they preserve the vehicle's existing setup. Many GL350s remain close to stock, but some may have wheel upgrades or suspension changes. Checking wheel width, offset, and full-turn steering clearance helps prevent problems that can appear even when the sidewall size looks familiar.
What rim-fitment details should I compare when choosing 2015 Mercedes-Benz Trucks GL350 tires?
For a 2015 Mercedes-Benz Trucks GL350, the most important rim-fitment detail is wheel diameter. The vehicle uses either a 19-inch or 20-inch rim, tied directly to the tire size. That means 275/55R19 and 275/50R20 are each built for their own wheel diameter and should not be treated as the same fitment.
Wheel width and offset also matter, especially on an SUV that may have been fitted with aftermarket wheels. Even when the nominal tire size is correct, changes in wheel specs can affect sidewall shape, steering clearance, and fender clearance. Checking the wheel setup before ordering helps keep the GL350's fitment stable and avoids choosing a tire that only looks correct on paper.
Restoration & Appearance
Does correct tire fitment matter for a 2015 Mercedes-Benz Trucks GL350 restoration or refurbishment?
Yes, correct tire fitment still matters on a 2015 Mercedes-Benz Trucks GL350 even though it is a modern luxury SUV rather than a vintage restoration piece. Using the proper 275/55R19 or 275/50R20 size for the wheel on the vehicle helps preserve the original visual balance and intended stance.
A refurbishment can lose its clean, factory-inspired look quickly if the tire size is mismatched to the wheel or if an altered package changes the proportions. Owners aiming for an authentic presentation should confirm the wheel diameter already on the SUV and avoid assuming that any close metric size will look or fit the same once mounted.
How does tire sizing affect the appearance of a 2015 Mercedes-Benz Trucks GL350?
Tire sizing has a clear effect on the appearance of a 2015 Mercedes-Benz Trucks GL350 because the sidewall profile changes with the wheel package. The 275/55R19 and 275/50R20 sizes keep a similar overall height, but the visual relationship between sidewall and wheel is different on the 19-inch and 20-inch setups.
That visual difference matters if the goal is to keep the SUV looking properly proportioned rather than over-wheeled or under-tired. Before changing sizes, verify the existing wheels and look at the vehicle as a complete package, including ride height and wheel offset. A size that technically mounts may still alter the GL350's overall presentation more than expected.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2015 Mercedes-Benz Trucks GL350?
Yes, modifications can affect tire fitment on a 2015 Mercedes-Benz Trucks GL350 even when the tire size appears close to stock. Wheel changes, altered offsets, suspension lowering, or other chassis modifications can all change how a 275/55R19 or 275/50R20 tire sits in the wheel opening and behaves at full steering lock.
That is why a replacement should be matched to the vehicle as it sits now, not only to the original configuration. Check wheel diameter first, then inspect wheel width, offset, and available clearance around the fenders and suspension. A GL350 with aftermarket wheels may need more careful measurement than one still using its original wheel package.
What should I inspect before driving a 2015 Mercedes-Benz Trucks GL350 on new tires?
Before driving a 2015 Mercedes-Benz Trucks GL350 on new tires, inspect wheel diameter, mounting condition, air pressure, and basic clearance around the tire. It is also wise to look for uneven suspension height, worn steering components, or signs that the old tires rubbed anywhere under load or during full steering travel.
A careful walkaround after installation helps catch issues early. Turn the steering from lock to lock, confirm there is no interference, and look again after a short drive for fresh contact marks or unusual air loss. On a heavier luxury SUV, small fitment issues can become noticeable quickly, so an early check is worthwhile even when the tire size is correct.
How often should tires on a 2015 Mercedes-Benz Trucks GL350 be inspected?
Tires on a 2015 Mercedes-Benz Trucks GL350 should be inspected regularly, not only when replacement time arrives. A monthly check is a good routine for pressure, tread condition, cuts, bulges, and visible sidewall damage, and the inspection should happen sooner any time the SUV develops vibration, pull, or a change in ride feel.
Routine inspections matter even more on vehicles that are driven less often or spend long periods parked. Low-use mileage does not prevent air loss, age-related cracking, or flat-spotting. Looking over the tires before longer highway trips is especially important, since a GL350's weight and road-speed use can magnify problems that may seem minor during casual local driving.
