The 2018 Buick Trucks Enclave belongs to Buick’s full-size crossover era, blending three-row family practicality with a more upscale road-going character than many utility vehicles in its class. Buyers often choose it for comfortable highway use, quiet cruising, and a clean, contemporary appearance that still matters when replacement tires are due. Tire fitment on the 2018 Buick Trucks Enclave centers on two radial sizes, 255/65R18 and 255/55R20, so the first step is confirming which wheel package is on the vehicle. Once that is settled, the decision shifts to matching the right metric radial size to the correct trim and overall wheel setup for everyday driving, replacement planning, and appearance consistency.
Which Tire Size Is Right for The 2018 Buick Trucks Enclave
The 2018 Buick Trucks Enclave uses two primary tire sizes, and the difference comes down to trim level and wheel diameter. Both are radial metric sizes, but one fits an 18-inch rim and the other fits a 20-inch rim, so confirming the exact sub-model and actual wheel setup should come before comparing tires. Some trims can use either size depending on configuration, which makes wheel verification especially important.
255/55R20 is a metric radial size in which 255 is the nominal section width in millimeters, 55 is the aspect ratio, R identifies radial construction, and 20 is the rim diameter in inches. On the 2018 Buick Trucks Enclave, this size is tied to 20-inch wheel applications and keeps the fitment in a modern radial format. Its dimensions place it very close in overall diameter to the 18-inch alternative, but it belongs to a different wheel package. This size should be evaluated by confirming the vehicle’s installed wheels and the exact trim configuration before replacement.
255/65R18 is a metric radial size where 255 gives the nominal section width in millimeters, 65 is the aspect ratio, R denotes radial construction, and 18 identifies the rim diameter. For the 2018 Buick Trucks Enclave, this size serves 18-inch wheel applications and is part of the vehicle’s primary fitment range. Its overall diameter is nearly the same as the 20-inch package, but the shorter wheel diameter means it is not chosen the same way. Selection starts with verifying the Enclave’s actual rim size, then matching the tire to that wheel and trim combination.
Sub-model fitment matters on the 2018 Buick Trucks Enclave because tire size varies by trim and wheel package. Some trims use one size only, while others appear with either 18-inch or 20-inch fitment, so checking the exact sub-model and installed wheels avoids ordering the wrong tire.
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2018 Buick Trucks Enclave Avenir
The 2018 Buick Trucks Enclave Avenir uses the 255/55R20 radial size. Tire selection for this trim starts with maintaining the correct 20-inch fitment and then choosing a replacement that matches the vehicle’s wheel package and intended road use.
The 2018 Buick Trucks Enclave Base uses the 255/65R18 radial size. That keeps the buying decision focused on the correct 18-inch wheel application rather than comparing it directly to the 20-inch fitment used elsewhere in the Enclave lineup.
The 2018 Buick Trucks Enclave Essence appears with either 255/65R18 or 255/55R20 radial fitment. For this trim, the key step is confirming the wheels currently on the vehicle before selecting tires, since both sizes belong to different rim diameters.
The 2018 Buick Trucks Enclave Premium can use either 255/65R18 or 255/55R20 radials depending on configuration. That makes wheel verification especially important, since the tire choice follows the installed 18-inch or 20-inch setup rather than the trim name alone.
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 answers focus on the tire sizes used on the 2018 Buick Trucks Enclave, how trim level and wheel diameter affect fitment, and what to inspect before choosing replacement tires or putting the vehicle back into regular road use.
Tire Size & Fitment
What tire size fits a 2018 Buick Trucks Enclave?
The 2018 Buick Trucks Enclave uses two tire sizes: 255/65R18 and 255/55R20. Both are radial metric sizes, but they do not serve the same wheel package, so the correct choice depends on the Enclave’s exact trim and installed rim diameter.
Avenir uses 255/55R20, while Base uses 255/65R18. Essence and Premium can appear with either size, which means the safest next step is to verify the actual wheel diameter on the vehicle before selecting tires rather than relying on trim name alone.
What size rim does a 2018 Buick Trucks Enclave use?
The 2018 Buick Trucks Enclave uses either an 18-inch rim or a 20-inch rim, depending on trim and wheel package. The 255/65R18 tire fits the 18-inch setup, while the 255/55R20 tire fits the 20-inch setup.
This matters because the two tire sizes have very similar overall diameter, but they are built for different wheel diameters and are not selected interchangeably. Checking the wheel itself is the quickest way to avoid a mismatch, especially on Essence and Premium models that can use either fitment.
Do all 2018 Buick Trucks Enclave sub-models use the same tire size?
No, 2018 Buick Trucks Enclave sub-models do not all use the same tire size. Avenir uses 255/55R20, Base uses 255/65R18, and Essence and Premium can be equipped with either size depending on the wheel package.
That variation means trim level alone is not always enough to choose a replacement tire. Looking at the current tire sidewall or measuring the wheel diameter is especially important on Essence and Premium models, since both 18-inch and 20-inch fitments appear within those sub-models.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Buick Trucks Enclave?
Start with the exact size already matched to the vehicle’s wheel package: either 255/65R18 or 255/55R20. The main decision is not between bias-ply and radial, since both primary Enclave fitments are radial, but between the correct wheel-related size and the tire characteristics that suit daily use.
Wheel diameter should be confirmed first, especially on Essence and Premium trims. After that, compare the tire’s intended use, load suitability, road manners, and how closely it matches the Enclave’s current setup so the vehicle keeps the proper fitment, clearance, and overall stance.
How do I choose between the available 255/55R20 and 255/65R18 tires for a 2018 Buick Trucks Enclave?
The choice between 255/55R20 and 255/65R18 is determined by the wheel diameter on the vehicle, not by preference alone. A 20-inch Enclave setup requires 255/55R20, while an 18-inch setup requires 255/65R18, even though the two sizes are close in overall diameter.
Once the correct size is established, compare tires within that size rather than across both sizes. That approach keeps the focus on proper rim fitment and helps avoid buying a tire that matches the Enclave’s general model year but not the wheels currently installed on the vehicle.
Why is wheel verification so important on a 2018 Buick Trucks Enclave?
Wheel verification matters because the 2018 Buick Trucks Enclave can use either 18-inch or 20-inch rim fitment, depending on trim and configuration. Essence and Premium models in particular may be found with either tire size, so the right replacement cannot be chosen by model year alone.
A quick check of the tire sidewall or the wheel itself prevents confusion between 255/65R18 and 255/55R20. It also helps account for vehicles that may have had wheel changes during ownership, which is common enough to make a visual confirmation worthwhile before purchasing new tires.
Restoration & Appearance
Does correct tire fitment matter for the appearance of a 2018 Buick Trucks Enclave?
Yes, correct tire fitment affects the appearance of a 2018 Buick Trucks Enclave as much as it affects function. Using the proper 255/65R18 or 255/55R20 size helps preserve the vehicle’s intended stance and keeps the wheel-and-tire proportion consistent with the trim’s original wheel package.
Because the two sizes are tied to different rim diameters, appearance changes if the wrong tire is paired with the wrong wheel. Owners who care about keeping the Enclave looking properly sorted should verify wheel size first, then choose a tire that maintains the right visual balance for that setup.
Which tire size should I keep for a stock-looking 2018 Buick Trucks Enclave?
A stock-looking 2018 Buick Trucks Enclave should stay with the tire size that matches its existing wheel package. That means 255/65R18 on 18-inch applications and 255/55R20 on 20-inch applications, depending on the trim and wheels actually installed on the vehicle.
Keeping the original wheel-related size is the simplest way to maintain the Enclave’s intended look without introducing unnecessary fitment questions. On Essence and Premium trims, where both sizes appear, checking the current wheels matters more than relying on a general assumption about the model.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Buick Trucks Enclave?
Yes, modifications can affect tire fitment on a 2018 Buick Trucks Enclave. Wheel changes, altered offsets, suspension lowering, and other aftermarket changes can all influence whether the original 255/65R18 or 255/55R20 size still has the intended clearance and wheel compatibility.
Any Enclave that has been changed from its original wheel package should be checked carefully before new tires are selected. Steering clearance, fender clearance, and the actual wheel diameter and width are more useful guides than trim name alone once a vehicle has been modified.
What should I inspect before driving a 2018 Buick Trucks Enclave on new tires?
Before driving a 2018 Buick Trucks Enclave on new tires, inspect the wheels for damage, confirm the tire size matches the rim diameter, and make sure the tires are properly inflated. It is also smart to check for any rubbing at full steering lock and look over the suspension for worn components.
A short initial drive can reveal vibration, pull, or clearance issues that are easier to address early. On a vehicle that has sat for long periods, inspect the older tires you removed for uneven wear patterns as well, since those can point to alignment or suspension concerns worth correcting.
How often should tires on a 2018 Buick Trucks Enclave be inspected?
Tires on a 2018 Buick Trucks Enclave should be inspected regularly, especially before longer drives and any time the vehicle has been parked for extended periods. Look for uneven tread wear, cuts, punctures, sidewall cracking, bulges, and signs of air loss on either 255/65R18 or 255/55R20 fitment.
Routine checks matter even more on vehicles that see mixed seasonal use or low annual mileage. Consistent pressure checks and visual inspection help catch problems before they affect road manners, and they also make it easier to confirm that the current tire setup still matches the Enclave’s wheels.
