The 2018 Buick Regal Sportback brought Buick into a more European-flavored fastback sedan format, combining everyday comfort with a sleeker profile and sharper road manners than many buyers expected from the badge. Its hatchback-style body also made it a practical modern touring car rather than just a traditional midsize sedan. Tire fitment varies across the lineup, with 225/55R17, 245/45R18, and 245/40R19 radial sizes tied to different trims and wheel packages. Available choices range from blackwall performance-oriented radials to Silvertown Radial options with wide whitewall or redline styling in 17-inch fitment. The right selection starts with confirming trim level and wheel diameter, then matching the tire's look and driving purpose to the car.
Which Tire Size Is Right for The 2018 Buick Regal Sportback
The 2018 Buick Regal Sportback uses three primary tire sizes, and the correct one depends on the exact sub-model and wheel diameter. All three are radial fitments, but they span 17-inch, 18-inch, and 19-inch rims, so confirming the car's current wheel setup comes first. Once that is settled, the decision shifts to tire character, sidewall style, and the balance between a modern performance look and a more distinctive period-inspired presentation.
225/55R17 is a metric radial size in which 225 identifies the section width in millimeters, 55 is the aspect ratio, R means radial construction, and 17 is the wheel diameter in inches. On the 2018 Buick Regal Sportback, this size serves the 17-inch wheel fitment and keeps the car within its intended modern radial tire format. Available choices include BFGoodrich performance-oriented g-Force series tires as well as Silvertown Radial options in blackwall-free appearance treatments such as wide whitewall and redline. It is the size to evaluate when the car has 17-inch wheels and the goal is either a standard late-model look or a more distinctive visual treatment.
245/45R18 is a metric radial size where 245 is the nominal section width in millimeters, 45 is the aspect ratio, R marks radial construction, and 18 identifies the wheel diameter. For the 2018 Buick Regal Sportback, this size belongs to 18-inch wheel applications and represents a wider, lower-profile setup than the 17-inch fitment. Product choices include BFGoodrich g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, and the Nitto NT555 G2, all in blackwall form. This is the size to match when the car carries the 18-inch wheel package and the owner wants to compare touring-performance versus more aggressive radial options.
245/40R19 follows the same metric radial format, with 245 denoting section width in millimeters, 40 showing the aspect ratio, R indicating radial construction, and 19 identifying the wheel diameter. On the 2018 Buick Regal Sportback, this size is tied to the 19-inch fitment and keeps a low-profile, modern appearance. Available options center on BFGoodrich blackwall tires in the g-Force Comp 2 AS, g-Force Sport Comp 2, and g-Force Phenom T/A series. This size should be considered when the car has 19-inch wheels and the priority is staying with the proper low-profile format for that specific setup.
Sub-model fitment matters on the 2018 Buick Regal Sportback because tire size changes across the lineup and follows wheel diameter. Identifying the exact trim, and confirming whether a Preferred model carries 17-inch or 18-inch wheels, is the key first step before comparing tire options.
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2018 Buick Regal Sportback Base
The 2018 Buick Regal Sportback Base uses the 225/55R17 radial fitment on a 17-inch wheel. That keeps tire selection focused on standard modern radial choices, with room to choose between performance-oriented blackwalls and more appearance-driven wide whitewall or redline options.
The 2018 Buick Regal Sportback Essence uses the 245/45R18 radial size with its 18-inch wheel setup. Tire selection here centers on blackwall radial options, so the main comparison points become brand, tire series, and wheel-width compatibility rather than sidewall treatment.
The 2018 Buick Regal Sportback GS uses the 245/40R19 radial fitment on a 19-inch wheel. That makes wheel confirmation especially important, since this low-profile size belongs to a different rim diameter and should be chosen with attention to the car's actual wheel and suspension setup.
The 2018 Buick Regal Sportback Preferred can use either a 225/55R17 or 245/45R18 radial tire depending on its wheel package. On this trim, checking the wheel diameter on the car itself is more important than relying on the trim name alone before choosing among available tire series and sidewall styles.
The 2018 Buick Regal Sportback Preferred II uses the 245/45R18 radial fitment. With this trim, the buying decision is less about size uncertainty and more about comparing the available blackwall radial tires by series, intended use, and rim-width compatibility.
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.
Best 2018 Buick Regal Sportback Tires for Sale
Available 2018 Buick Regal Sportback tire choices span BFGoodrich and Nitto, with g-Force and NT555 G2 performance-oriented blackwall radials across the 17-, 18-, and 19-inch sizes. In 225/55R17, Silvertown Radial options add wide whitewall and redline styling for a more distinctive appearance.
These FAQs focus on the exact tire sizes used on the 2018 Buick Regal Sportback, how trim level and wheel diameter affect fitment, and how to compare available radial tires by style, series, and practical road-use considerations.
Tire Size & Fitment
What tire size fits a 2018 Buick Regal Sportback?
The 2018 Buick Regal Sportback uses three primary tire sizes: 225/55R17, 245/45R18, and 245/40R19. Each is a radial size, and the correct one depends on the specific trim and wheel package rather than the model name alone.
Base models use 225/55R17, Essence and Preferred II use 245/45R18, and GS uses 245/40R19. Preferred models can use either 225/55R17 or 245/45R18, so the safest next step is to confirm the wheel diameter on the car before selecting a tire.
What size rim does a 2018 Buick Regal Sportback use?
A 2018 Buick Regal Sportback can use 17-inch, 18-inch, or 19-inch rims depending on trim level and wheel package. Those rim diameters correspond to the three primary tire sizes used on the car: 225/55R17, 245/45R18, and 245/40R19.
Rim diameter is the first fitment detail to verify because a 17-inch tire does not belong on an 18-inch or 19-inch wheel, and the same is true in reverse. On Preferred models especially, checking the actual wheel on the vehicle prevents ordering the right width and profile in the wrong diameter.
Why does the 2018 Buick Regal Sportback have more than one tire size?
The 2018 Buick Regal Sportback has more than one tire size because different trims use different wheel diameters and tire profiles. The lineup spans 17-inch, 18-inch, and 19-inch wheel fitments, so tire size changes with the specific configuration.
That means trim identification matters, but wheel confirmation matters even more if the car has changed hands or has had replacement wheels installed. A Preferred trim is the clearest example, since it can use either 225/55R17 or 245/45R18 depending on the setup on the car.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Buick Regal Sportback?
Start with the correct tire size for the exact trim and wheel diameter, since the 2018 Buick Regal Sportback uses 225/55R17, 245/45R18, or 245/40R19 depending on configuration. From there, compare tire series, sidewall style, rim-width compatibility, and whether the tire matches the car's intended use.
A driver-focused car may call for one of the g-Force or NT555 G2 blackwall radials, while a 17-inch car can also be fitted with Silvertown Radial wide whitewall or redline options for a more distinctive look. Matching the tire to both the wheel and the way the car is driven leads to a better choice than focusing on size alone.
What sidewall styles are available for 2018 Buick Regal Sportback tires?
Sidewall style depends on the tire size used on the 2018 Buick Regal Sportback. Blackwall options are available across all three primary sizes, while 225/55R17 also offers more appearance-oriented choices including wide whitewall and redline treatments.
That makes the 17-inch fitment the broadest visual choice for an owner who wants something beyond a standard late-model black sidewall. The 18-inch and 19-inch sizes stay focused on blackwall performance-style radials, so the main selection differences there come from tire series and brand rather than sidewall design.
What brands offer tires for the 2018 Buick Regal Sportback?
BFGoodrich appears across all three primary tire sizes for the 2018 Buick Regal Sportback, and Nitto is also available in 245/45R18. Within the BFGoodrich range, the available series include g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, and Silvertown Radial in 17-inch fitment.
Brand choice matters most after the correct size is settled, because each size does not carry the same assortment. A 245/45R18 car has both BFGoodrich and Nitto to compare, while 225/55R17 adds BFGoodrich options with very different visual presentations through blackwall, wide whitewall, and redline versions.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Buick Regal Sportback?
Yes, modifications can affect tire fitment on a 2018 Buick Regal Sportback even when the tire size matches one of the original wheel diameters. Changes such as aftermarket wheels, altered offset, suspension lowering, or body modifications can change clearance at the fender, suspension, or steering components.
A car that originally used 225/55R17, 245/45R18, or 245/40R19 should still be checked as an individual vehicle if anything has changed from stock. Verifying wheel width, rim diameter, and clearance at full steering lock is especially important before choosing a tire for a modified Regal Sportback.
What should I inspect before driving a 2018 Buick Regal Sportback on new tires?
Before driving a 2018 Buick Regal Sportback on new tires, inspect the wheels for correct diameter and condition, confirm that all four tires are the intended size, and check inflation pressure. It also helps to look for any suspension, alignment, or brake issues that could affect how the new tires wear.
A short road test should include listening for rubbing, feeling for vibration, and checking steering response at low and moderate speeds. After the first drives, recheck pressure and inspect for any unusual marks on the sidewall or tread, especially if the car has replacement wheels or a nonstandard setup.
How often should tires on a 2018 Buick Regal Sportback be inspected?
Tires on a 2018 Buick Regal Sportback should be inspected regularly, not just when tread appears low. Routine checks should include pressure, tread wear pattern, visible cuts, bulges, sidewall damage, and any signs of uneven wear that could point to alignment or suspension issues.
Monthly checks are a practical habit, and the tires should also be looked over before a longer drive or after a pothole impact. On a car that sees limited seasonal use, age and storage conditions matter too, since a low-mileage tire can still become unsuitable for road use even when tread depth looks good.
