The 2018 Mercedes-Benz Trucks G63 AMG carries the long-running G-Class formula into the modern AMG era, blending hand-built performance with the upright shape and off-road heritage that made the platform so recognizable. Buyers looking at one today are usually balancing luxury SUV road manners with the stance and presence that define the model. Tire fitment centers on two radial sizes, 275/50R20 and 295/35R21, tied to different wheel diameters. That makes the real choice less about vintage construction and more about confirming the wheel setup already on the vehicle. Once that is settled, selection comes down to matching the correct size to ride, appearance, and intended use.
Which Tire Size Is Right for The 2018 Mercedes-Benz Trucks G63 AMG
The 2018 Mercedes-Benz Trucks G63 AMG uses two primary tire sizes, and the difference starts with wheel diameter. One setup uses a 20-inch rim with 275/50R20 tires, while the other uses a 21-inch rim with 295/35R21 tires. Since the Base sub-model can use either size, the first step is confirming which wheels are actually on the vehicle before comparing tires.
The 275/50R20 size uses a modern metric radial format: 275 is the nominal section width in millimeters, 50 is the aspect ratio, R identifies radial construction, and 20 is the wheel diameter in inches. On the 2018 Mercedes-Benz Trucks G63 AMG, this size supports a taller sidewall than the 21-inch alternative while staying within a modern high-performance SUV fitment style. It is the right size to evaluate when the vehicle has 20-inch wheels. Checking the exact wheel size on the truck matters before moving forward with any replacement.
The 295/35R21 size is also a modern metric radial, with 295 millimeters of nominal width, a 35-series profile, radial construction, and a 21-inch wheel diameter. For the 2018 Mercedes-Benz Trucks G63 AMG, this fitment represents the larger-diameter wheel setup and a lower-profile tire than the 20-inch option. That changes the fitment conversation immediately, because wheel diameter must match before any tire can be considered. This is the size to focus on when the vehicle is already equipped with 21-inch wheels and the goal is to stay with that configuration.
Fitment is straightforward at the sub-model level because the covered Base version can use both primary tire sizes. The important detail is not trim variation, but verifying whether the vehicle is running the 20-inch or 21-inch wheel package before selecting tires.
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2018 Mercedes-Benz Trucks G63 AMG Base
The 2018 Mercedes-Benz Trucks G63 AMG Base can use either of the two radial tire sizes offered for this model year. That means tire selection starts with confirming the installed wheel diameter, then choosing the correct size within that setup rather than assuming one fitment applies to every vehicle.
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 2018 Mercedes-Benz Trucks G63 AMG usually center on its two tire sizes, the difference between the 20-inch and 21-inch wheel setups, and what owners should inspect before replacing tires or putting the vehicle back into regular road use.
Tire Size & Fitment
What tire size fits a 2018 Mercedes-Benz Trucks G63 AMG?
The 2018 Mercedes-Benz Trucks G63 AMG uses two primary tire sizes: 275/50R20 and 295/35R21. Both are radial sizes, and each corresponds to a different wheel diameter, so they are not interchangeable without matching the correct rim.
The key step is verifying which wheels are on the vehicle now. A G63 AMG may be equipped with either 20-inch or 21-inch wheels, and the right tire choice follows that setup. Checking the sidewall of the current tire and confirming the wheel diameter before replacement helps avoid ordering the wrong size.
What size rim does a 2018 Mercedes-Benz Trucks G63 AMG use?
The 2018 Mercedes-Benz Trucks G63 AMG uses either a 20-inch or 21-inch rim, depending on which tire size is on the vehicle. The 275/50R20 tire fits a 20-inch rim, while the 295/35R21 tire fits a 21-inch rim.
That rim difference is the most important fitment detail on this model. Before selecting tires, confirm the actual wheel diameter rather than relying on appearance alone, since both sizes are used on the same sub-model. Once the wheel size is confirmed, the tire search becomes much more straightforward and accurate.
Why does the 2018 Mercedes-Benz Trucks G63 AMG have more than one tire size?
The 2018 Mercedes-Benz Trucks G63 AMG has more than one tire size because it was fitted with more than one wheel diameter. The two supported sizes, 275/50R20 and 295/35R21, reflect different wheel-and-tire setups rather than a bias-ply versus radial change or a different sub-model family.
That means the correct choice depends on the wheels actually installed on the vehicle today. A tire should be selected to match the existing rim diameter first, then reviewed for overall fitment around suspension and body clearance if the vehicle has been modified. Matching the current setup is more important than choosing by appearance alone.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Mercedes-Benz Trucks G63 AMG?
Start with the correct primary size for the wheel already on the vehicle: 275/50R20 for a 20-inch rim or 295/35R21 for a 21-inch rim. Both are radial fitments, so the main decision is not construction type but selecting the proper size for the existing wheel setup.
After size, focus on how the vehicle is used. A G63 AMG that sees mostly street driving may lead an owner toward one type of road-focused tire, while a different use pattern may shift priorities. Wheel diameter, clearance, load needs, and the condition of any aftermarket wheels should all be reviewed before final selection.
How do I choose between the available 2018 Mercedes-Benz Trucks G63 AMG tire sizes?
Choose between the two available sizes by matching the tire to the wheel diameter already installed. The 275/50R20 belongs on a 20-inch wheel, and the 295/35R21 belongs on a 21-inch wheel. The vehicle uses both sizes, but not on the same rim.
The decision is usually made by the wheel package on the truck rather than personal preference alone. If the G63 AMG has been changed from its prior setup, inspect the wheel markings and current tire sidewall to confirm the exact fitment. That check prevents size confusion and keeps the replacement process focused on the right options.
What does 275/50R20 mean on a 2018 Mercedes-Benz Trucks G63 AMG?
On a 2018 Mercedes-Benz Trucks G63 AMG, 275/50R20 is a modern metric radial size. The 275 is the nominal section width in millimeters, 50 is the aspect ratio, R means radial construction, and 20 identifies the wheel diameter in inches.
Understanding that code helps separate tire width and profile from wheel size. The most important part for fitment is the 20 at the end, because that tire can only be used on a 20-inch rim. If the vehicle is running 21-inch wheels instead, the correct primary size moves to 295/35R21.
Restoration & Appearance
Does correct tire fitment matter for a 2018 Mercedes-Benz Trucks G63 AMG restoration or preservation project?
Yes, correct tire fitment still matters on a 2018 Mercedes-Benz Trucks G63 AMG, even though it is a modern vehicle rather than a vintage restoration subject. The right size preserves the intended relationship between wheel diameter, sidewall profile, and the vehicle's overall stance.
A preservation-minded owner should first confirm whether the truck is wearing the 20-inch or 21-inch setup it currently carries, then stay consistent within that package unless there is a deliberate reason to change. If originality matters closely, comparing the current wheels and tires against vehicle history, photos, or prior ownership records is worthwhile.
How does tire size affect the appearance of a 2018 Mercedes-Benz Trucks G63 AMG?
Tire size has a clear effect on the appearance of a 2018 Mercedes-Benz Trucks G63 AMG because the two fitments use different wheel diameters and different sidewall proportions. The 275/50R20 setup presents more sidewall, while the 295/35R21 setup pairs a wider, lower-profile tire with a larger wheel.
That visual difference is one reason it is important to match replacement tires to the wheel package already on the vehicle. Owners trying to preserve a particular look should verify both wheel size and tire size before replacing a set. Small changes in sidewall profile can noticeably alter the truck's stance and overall presentation.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Mercedes-Benz Trucks G63 AMG?
Yes, modifications can affect tire fitment on a 2018 Mercedes-Benz Trucks G63 AMG. Aftermarket wheels, changes in wheel offset, suspension alterations, or body modifications can all change how a 275/50R20 or 295/35R21 tire sits within the wheel opening and around steering and suspension components.
That matters even when the tire size itself is one of the correct primary fitments. A modified vehicle should be checked for wheel diameter, wheel width, clearance at full steering lock, and any signs of rubbing before replacement tires are chosen. The closer the setup is kept to the existing proven combination, the fewer surprises usually follow.
What should I inspect before driving a 2018 Mercedes-Benz Trucks G63 AMG on new tires?
Before driving a 2018 Mercedes-Benz Trucks G63 AMG on new tires, inspect the wheels for damage, confirm the correct tire size for the installed rim diameter, and look over suspension and steering components for obvious wear. Tire pressure should also be set correctly before the vehicle goes back into regular use.
A careful walk-around is especially helpful if the vehicle has been parked for long periods or recently changed hands. Look for uneven old-tire wear that might suggest alignment or suspension issues, and make sure the new tires clear properly through the steering range. Catching those issues early helps the new set wear more evenly from the start.
What should I check before a longer drive in a 2018 Mercedes-Benz Trucks G63 AMG?
Before a longer drive in a 2018 Mercedes-Benz Trucks G63 AMG, check tire pressure, tread condition, sidewall condition, and any signs of cuts, bulges, or slow air loss. It is also smart to verify that all four tires match the wheel size installed on the vehicle, whether that is the 20-inch or 21-inch setup.
Longer trips place more importance on condition than a short local drive. Tires that look acceptable while parked can still have age-related cracking or damage that becomes more serious at highway speed. Reviewing the spare situation, wheel hardware, and general road readiness before departure gives the vehicle a better chance of trouble-free travel.
