2015 Buick Tire Fitment Guide

2015 Buick vehicles use nine tire sizes across three models. The LaCrosse uses 225/55R17, 235/50R18, 245/45R19, and 245/40R20; the Regal uses 235/50R17, 235/50R18, 245/40R19, and 255/35R20; and the Verano uses 225/50R17 and 235/45R18. These sizes span 17-, 18-, 19-, and 20-inch wheel diameters, so there is no single tire size that fits the full 2015 Buick range.

That means year and make alone are not enough for a confident choice. Start by identifying the exact model, then confirm the wheel diameter already on the car before comparing brands or tread designs. Rim-width ranges also vary by size, with examples running from 6.0-8.0 inches in some 17-inch applications up to 8.5-10.0 inches in the 255/35R20 size, so verifying the actual wheel is a smart final check.

On a 2015 Buick, 225/55R17 is a metric radial size. The 225 is the tire’s nominal section width in millimeters, 55 is the aspect ratio, meaning the sidewall height is 55 percent of that width, R identifies radial construction, and 17 is the wheel diameter in inches. On 2015 Buick applications, this size is used on the LaCrosse.

That code matters because it tells you more than width alone. A 225/55R17 requires a 17-inch wheel, and the available products in this size suit rim widths from about 6.0 to 9.0 inches depending on the tire chosen. If your LaCrosse currently wears 17-inch wheels, this is the size family to compare before moving on to sidewall appearance or speed rating.

No, 2015 Buick models do not use the same tire size. Only one size, 235/50R18, is shared between two models, the LaCrosse and Regal. Every other size is tied to a specific model and wheel package, including Verano-exclusive sizes such as 225/50R17 and 235/45R18, plus Regal- and LaCrosse-specific 19- and 20-inch fitments.

For a buyer, that means the model badge matters every bit as much as the year. It also means you should not assume that another 2015 Buick sedan in the driveway uses the same tire just because it looks similar at a glance. Once the model is confirmed, check the current wheel diameter and tire sidewall to keep the search focused on the right fitment family.

Most 2015 Buick tire sizes are available in Blackwall form, which matches the contemporary look expected on a late-model Buick sedan. Two sizes broaden that appearance range: 225/55R17 is available with a Wide Whitewall option, and 245/40R20 is available with an RWL sidewall in addition to Blackwall. Those are styling choices rather than alternate fitment codes, since the size itself still has to match the wheel and vehicle application.

If you are keeping a 2015 Buick visually close to factory character, Blackwall is usually the most natural direction. A whitewall or raised white letter treatment can change the personality of the car substantially, which may appeal more to custom-minded owners than to someone preserving an original late-model appearance. Decide on the look after the correct size is confirmed, not before.

2015 Buick tire sizes are covered by BFGoodrich, Nitto, and Pro-Trac, depending on the exact size. BFGoodrich appears across every size family here, Nitto supports several 17-, 18-, 19-, and 20-inch applications, and Pro-Trac enters the picture in 245/40R20. Brand coverage is broadest in shared and larger-diameter sizes such as 235/50R18, 245/40R20, and 255/35R20.

That spread gives Buick owners a useful range of choices within the same basic fitment. Smaller or more model-specific sizes may narrow the field, while common late-model sizes often open up more than one brand and more than one performance-oriented series. The practical move is to identify your exact size first, then compare the brands available within that size rather than cross-shopping one size against another.

For 2015 Buick sizes where both appear, BFGoodrich g-Force COMP-2 A/S and Nitto NT555 G2 often share the same overall wheel diameter and speed rating letter, but they do not always carry identical load details or rim-width notation. In 235/50R18, for example, the Nitto NT555 G2 carries a 101W load/speed designation with a stated 1,819-pound load at 50 psi, while the BFGoodrich g-Force COMP-2 A/S appears as 97W. Similar differences show up in other shared sizes, even when both remain within the same fitment family.

That makes the decision less about one being universally better and more about matching the product to your priorities. Compare the exact size, speed rating, load index, and approved rim-width range on the tire you are considering. If your Buick already has a particular wheel width or if you place extra value on a specific specification on the sidewall, those details can steer the final choice more effectively than brand name alone.

Rim-width requirements for 2015 Buick tires vary by size. 225/55R17 and 225/50R17 work on roughly 6.0-8.0 inches, with one 225/55R17 radial extending to 9.0 inches; 235/50R17 uses 6.5-8.5 inches; 235/50R18 uses about 6.5-8.5 inches; 235/45R18 uses 7.5-9.0 inches; 245/45R19 uses 7.5-9.0 inches; 245/40R19 and 245/40R20 use about 8.0-9.5 inches; and 255/35R20 uses 8.5-10.0 inches.

Those ranges are wide enough that the wheel already on your Buick still needs to be checked, especially if the car has aftermarket rims. A tire can share the correct diameter and still have a narrower or wider approved wheel range than another product in the same size family. Matching the tire to the actual wheel width is the last fitment step before making a final product choice.

The 2015 Buick tire products here are modern radials and do not carry tube-type markings such as TT. They are presented in tubeless radial sizing formats such as 225/55R17, 235/50R18, and 255/35R20, which is consistent with how late-model Buick sedans were equipped. Nothing in these size groups suggests a tube-type application in normal use.

Even so, the wheel condition still matters. If a Buick has damaged rims, nonstandard custom wheels, or a special-use setup, the correct approach is to inspect the wheel itself and follow the tire manufacturer’s mounting guidance. For a typical stock 2015 Buick wheel, the main concern is choosing the proper size and confirming the wheel is sound, not sourcing an inner tube.

A stored 2015 Buick should be kept out of direct sunlight and away from ozone-producing equipment such as electric motors, battery chargers, and some compressors. Clean, dry floors and stable temperatures help, and the car should be moved periodically so the tires are not carrying the same load point for months at a time. These are all radial tires, so long-term flat-spotting is generally less pronounced than with old-style bias-ply construction, but static storage still ages rubber.

If the car will sit for a season or longer, maintain proper inflation, keep the tires clean, and consider stands or tire cradles for extended storage. That is especially worthwhile on larger wheel packages with shorter sidewalls, where cosmetic sidewall damage can show quickly. Good storage habits preserve both appearance and service life, even on a relatively modern collector Buick.

For a 2015 Buick that sees collector-style or occasional use, age matters more than mileage alone. A practical rule is to begin evaluating tires closely around five to seven years of age and to treat ten years as a serious replacement consideration, even if tread depth still looks usable. The DOT date code on the sidewall is the best way to determine the tire’s actual age.

That matters because a Buick driven only on weekends can still age out its tires before wearing them out. Heat cycles, sun exposure, storage conditions, and pressure maintenance all influence service life. If a tire is approaching the upper end of its age window, hardening rubber or small sidewall cracks can become more important than the remaining tread pattern.

Tires on a 2015 Buick should be inspected before every drive and again before any longer highway outing. Check for sidewall cracking, punctures, abnormal tread wear, bulges, and air loss, and make sure each tire is holding the intended pressure. On a modern Buick sedan, that routine inspection is as important on lightly used cars as it is on daily drivers.

A quick walkaround catches problems early and helps separate ordinary wear from alignment or suspension issues. Pay extra attention if the car has been stored, parked outside, or fitted with larger 19- or 20-inch wheel packages, since impacts and low-profile sidewalls can make damage easier to miss at a glance. Consistent inspections are one of the simplest ways to keep an older late-model Buick road-ready.

Yes, the tire sizes used on 2015 Buick vehicles are highway-capable when they are in good condition, correctly inflated, and matched to the proper wheel and application. These products are all radial designs, and the speed ratings that appear here are primarily W, with a 112 mph ceiling, and Y, rated for 186+ mph on certain sizes such as 245/45R19, 245/40R20, 245/40R19, and 255/35R20. Those figures are well above ordinary U.S. highway speeds.

Real-world safety still depends on more than the tire’s letter rating. Tire age, inflation, alignment, road damage, and the Buick’s overall mechanical condition matter just as much in normal use. For a highway trip, the most important takeaway is to run the correct size, inspect each tire carefully, and avoid assuming that a high speed rating makes an older or damaged tire safe.

Inflation pressure for a 2015 Buick should follow the vehicle’s factory recommendation first, since the exact target pressure is tied to the model, axle loading, and wheel package. Several tires here also carry their own maximum load and pressure figures, such as 1609 pounds at 51 psi in some 225/55R17 and 235/50R18 products, 1819 pounds at 50 psi in some 225/55R17 and 235/50R18 products, 1653 pounds at 50 psi in some 245/40R19, 225/50R17, and 235/45R18 products, 1709 pounds at 50 psi in one 245/40R20 product, and 1874 pounds at 50 psi in one 245/45R19 product.

Those sidewall figures are load-related limits, not universal running pressures for every 2015 Buick. The safest approach is to use the pressure specified on the Buick placard or in the owner’s manual for your exact model and wheel package, then confirm that the tire itself is suitable for that use. Do not transfer a pressure number from one size family to another just because the cars share the same year and make.

Before a longer drive in a 2015 Buick, inspect all four tires and the spare for cracking, cuts, punctures, bulges, uneven wear, and correct inflation. Also look at the valve stems, check that the tires are matched in size across each axle as intended, and make sure none of the wheels show obvious impact damage. A late-model Buick can feel refined enough to mask early tire problems, so the visual inspection matters.

Tires are only one part of the pre-trip routine, but they are the only part of the car touching the road. It is wise to pair the tire check with a quick look at brakes, fluids, battery condition, and suspension health, especially on a car that is driven intermittently. Starting with the right tire size and a clean inspection baseline helps the rest of the trip go more smoothly.