The 2018 Mazda Trucks CX-9 is a three-row crossover shaped more like a road-focused family vehicle than a traditional truck-based SUV, so tire choice has a noticeable effect on both stance and everyday drivability. In this generation, the CX-9 balanced upscale styling with practical use, and trim level matters when selecting replacement tires. The 2018 Mazda Trucks CX-9 uses radial tires in two primary sizes: 255/50R20 and 255/60R18. That means the first step is confirming the exact sub-model and wheel diameter, then choosing the right tire within that size for appearance, road use, and overall fitment consistency.
Which Tire Size Is Right for The 2018 Mazda Trucks CX-9
Two tire sizes apply to the 2018 Mazda Trucks CX-9, and the correct one depends on sub-model and wheel diameter. Both are radial fitments, but one uses an 18-inch rim and the other uses a 20-inch rim, so confirming the exact trim and the wheels currently on the vehicle is the first step before comparing tire choices.
255/50R20 is a metric radial size in which 255 identifies the nominal section width in millimeters, 50 is the aspect ratio, R indicates radial construction, and 20 is the rim diameter in inches. On the 2018 Mazda Trucks CX-9, this size belongs to trims equipped with 20-inch wheels rather than the 18-inch setup. Its overall dimensions stay close to the alternate CX-9 size, but the wheel requirement is different. Choose this size only after confirming that the vehicle is one of the 20-inch-wheel sub-models or already carries the correct 20-inch rims.
255/60R18 is a metric radial size where 255 is the nominal section width in millimeters, 60 is the aspect ratio, R marks radial construction, and 18 identifies the required rim diameter in inches. For the 2018 Mazda Trucks CX-9, this size is used on trims built around an 18-inch wheel package. Although it shares a similar overall diameter with the 20-inch fitment, it is not simply a matter of choosing either size. This is the right path when the vehicle has the correct 18-inch wheels and matching trim-level fitment.
Tire fitment on the 2018 Mazda Trucks CX-9 varies by sub-model, and the split follows wheel diameter as well as tire size. Checking the exact trim matters because the Sport and Touring use one radial size, while the Grand Touring and Signature use another.
1
2018 Mazda Trucks CX-9 Grand Touring
The 2018 Mazda Trucks CX-9 Grand Touring uses the 255/50R20 radial size on a 20-inch wheel package. Tire selection for this trim starts with confirming the 20-inch wheels, then comparing replacement choices within that size rather than looking at the 18-inch CX-9 fitment.
The 2018 Mazda Trucks CX-9 Signature also uses the 255/50R20 radial size. That keeps the focus on proper 20-inch rim fitment and selecting a tire that matches the vehicle's existing wheel setup and intended road use.
The 2018 Mazda Trucks CX-9 Sport uses the 255/60R18 radial size with an 18-inch wheel. For this trim, the main fitment task is staying with the 18-inch setup unless the vehicle has been changed from its original wheel package.
The 2018 Mazda Trucks CX-9 Touring uses the same 255/60R18 radial size as the Sport. That makes replacement straightforward as long as the CX-9 still carries the correct 18-inch wheels and has not been altered with a different wheel and tire package.
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
These 2018 Mazda Trucks CX-9 tire FAQs focus on the two correct sizes, trim-level fitment, wheel diameter, practical tire selection, and the checks that matter before driving on replacement tires.
Tire Size & Fitment
What tire size fits a 2018 Mazda Trucks CX-9?
The 2018 Mazda Trucks CX-9 uses two tire sizes: 255/50R20 and 255/60R18. Both are radial sizes, and the correct one depends on the sub-model. Grand Touring and Signature use 255/50R20, while Sport and Touring use 255/60R18.
The key is not choosing between two similar sizes by preference, but matching the tire to the wheel diameter and trim-level setup already on the vehicle. A 20-inch tire belongs on a 20-inch wheel, and an 18-inch tire belongs on an 18-inch wheel, so confirm both the sub-model and the actual wheels before replacement.
What size rim does a 2018 Mazda Trucks CX-9 use?
A 2018 Mazda Trucks CX-9 uses either an 18-inch or 20-inch rim, depending on sub-model. The 255/60R18 fitment uses an 18-inch rim, and the 255/50R20 fitment uses a 20-inch rim.
Rim diameter is the first fitment checkpoint because tire size and wheel size must match exactly. Before replacing tires, inspect the wheels actually on the vehicle, especially if it was purchased used or may have been modified. A CX-9 that now wears different wheels may no longer match the original trim-level tire specification.
Do all 2018 Mazda Trucks CX-9 sub-models use the same tire size?
No. The 2018 Mazda Trucks CX-9 has split fitment across its sub-model range. Grand Touring and Signature use 255/50R20, while Sport and Touring use 255/60R18, so tire size is tied directly to the trim and wheel package.
That matters because the two sizes require different rim diameters even though their overall dimensions are very close. Anyone replacing tires should identify the exact sub-model and check the wheels on the vehicle rather than assuming every 2018 CX-9 uses the same setup. That avoids ordering an 18-inch tire for a 20-inch wheel, or the other way around.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Mazda Trucks CX-9?
Start with the correct size for the exact 2018 Mazda Trucks CX-9 sub-model: 255/50R20 for Grand Touring and Signature, or 255/60R18 for Sport and Touring. Since both fitments are radial, the main selection issue is matching the existing wheel diameter and staying within the proper size rather than choosing between bias-ply and radial construction.
After confirming size, look at how the CX-9 is used. A daily-driven crossover may need different priorities than a lightly used family vehicle, but the fitment basics remain the same. Check the current wheels, compare the replacement tire's dimensions to the vehicle's setup, and avoid mixing sizes intended for different trim-level wheel packages.
How do I choose between the available 255/50R20 and 255/60R18 tires for a 2018 Mazda Trucks CX-9?
The choice is determined by the vehicle's trim-level fitment and wheel diameter, not by personal preference between the two sizes. A 2018 Mazda Trucks CX-9 with 20-inch wheels uses 255/50R20, while one with 18-inch wheels uses 255/60R18.
Once the correct size is identified, compare replacement options within that single size rather than across both. The two sizes are built around different wheel diameters, so they are separate fitment paths. Checking the sidewall on the current tires and measuring the wheel diameter is a smart step, especially if the vehicle has had wheels replaced at some point.
Why does the 2018 Mazda Trucks CX-9 have more than one tire size?
The 2018 Mazda Trucks CX-9 has more than one tire size because different sub-models were equipped with different wheel packages. Sport and Touring use 255/60R18, while Grand Touring and Signature use 255/50R20, with both sizes remaining radial constructions.
This kind of split fitment is common when one trim uses a larger wheel for a different visual and equipment package. Even though the two sizes have very similar overall diameters, the tire still has to match the wheel diameter exactly. That is why trim identification and wheel inspection matter before any replacement decision is made.
Restoration & Appearance
Does correct tire fitment matter for a 2018 Mazda Trucks CX-9 restoration or preservation project?
Yes. Even on a late-model collector or preservation-minded 2018 Mazda Trucks CX-9, correct tire fitment still matters because the vehicle uses two different trim-based sizes. Keeping the proper 255/50R20 or 255/60R18 setup helps preserve the intended wheel-and-tire relationship for that specific sub-model.
Appearance is only part of the story. The right size also keeps the tire matched to the wheel diameter the vehicle was built around, which affects how the CX-9 sits and how the wheel wells are visually filled. On a preservation project, checking the trim, current wheels, and any prior wheel changes is just as important as choosing a fresh set of tires.
How does tire size affect the appearance of a 2018 Mazda Trucks CX-9?
Tire size affects appearance on a 2018 Mazda Trucks CX-9 because the vehicle was offered with both 18-inch and 20-inch wheel packages. The 255/60R18 and 255/50R20 sizes are close in overall diameter, but each creates a different visual balance because of the wheel size and sidewall proportion.
For an owner trying to keep the vehicle looking true to its trim, matching the original size path is the safer approach. A Sport or Touring looks right on its 18-inch-based fitment, while Grand Touring and Signature align with the 20-inch setup. Before changing the wheel-and-tire combination, check clearance, wheel compatibility, and the overall presentation you want to maintain.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Mazda Trucks CX-9?
Yes. Modifications can affect tire fitment on a 2018 Mazda Trucks CX-9, especially if the vehicle has aftermarket wheels, altered suspension height, or body changes that reduce normal clearance. The original fitments are 255/50R20 and 255/60R18, each tied to a specific rim diameter.
A CX-9 that has been lowered, lifted, or changed to non-original wheels should be checked carefully before tire replacement. Confirm actual wheel diameter and width, inspect clearance at full steering lock, and look for signs of rubbing near the fenders or suspension components. Those checks matter more than trim-level assumptions once modifications enter the picture.
What should I inspect before driving a 2018 Mazda Trucks CX-9 on new tires?
Before driving a 2018 Mazda Trucks CX-9 on new tires, confirm that the correct size was installed for the vehicle's wheel package and that all four tires are seated properly and inflated to the appropriate pressure for the vehicle. It is also wise to inspect the wheels for damage and make sure lug hardware is secure.
A short road test should be paired with a visual check for rubbing, unusual vibration, or steering pull. The CX-9 should also be examined for suspension wear, especially if the previous tires showed uneven wear patterns. Catching alignment or clearance problems early helps protect the new tires and keeps the vehicle more consistent in everyday road use.
How often should tires on a 2018 Mazda Trucks CX-9 be inspected?
Tires on a 2018 Mazda Trucks CX-9 should be inspected regularly, not just when they appear worn. Monthly pressure checks, frequent visual inspections, and a closer look before longer drives are smart habits, especially for a vehicle that carries passengers and sees mixed daily use.
Look for uneven tread wear, cuts, bulges, cracking, and slow air loss, and compare all four tires to make sure the size remains consistent with the vehicle's wheel setup. A CX-9 that sits for long periods still needs inspection because age and storage conditions can affect tire condition. Regular checks help catch problems before they turn into ride, handling, or clearance issues.
