The 2015 Buick Regal sits in the modern sport-sedan part of Buick’s lineup, blending everyday comfort with a sharper European-influenced character than many buyers expect from the badge. Tire choice matters here because the Regal’s stance and road manners change noticeably across its sub-model range. Depending on trim, the 2015 Buick Regal uses radial tire sizes from 235/50R17 up to 255/35R20. That means some owners will be comparing practical blackwall replacements, while others may also see redline or raised white letter options in larger sizes. The right selection starts with the exact sub-model and wheel diameter, then moves to the appearance and driving style that best suit the car.
Which Tire Size Is Right for The 2015 Buick Regal
The 2015 Buick Regal uses four different primary tire sizes, and the correct one depends on the exact sub-model and wheel diameter. Sizes span 17-, 18-, 19-, and 20-inch rims, so the first step is confirming which wheels are actually on the car. After that, the decision becomes choosing the right radial tire within the correct size, including brand, tire series, and sidewall style where those options exist.
235/50R18 is a metric radial size where 235 is the nominal section width in millimeters, 50 is the aspect ratio, R identifies radial construction, and 18 is the rim diameter in inches. On the 2015 Buick Regal, this size serves trims that use an 18-inch wheel and keeps the tire choice in a fully modern radial format. Available options include BFGoodrich, Nitto, and Pro-Trac, with blackwall, redline, and RWL sidewall treatments across several tire series. This size is the one to evaluate when the car has factory-style 18-inch fitment and the goal is to balance correct dimensions with the preferred look.
245/40R19 is a metric radial size with a 245-millimeter nominal section width, a 40-series profile, and a 19-inch rim diameter. On the 2015 Buick Regal, this size is tied to a specific wheel setup and should be treated as a trim-specific fitment rather than a universal Regal size. BFGoodrich offers this size in multiple g-Force series, all in blackwall form, giving buyers a choice of product character without changing the basic fitment format. It is the right size to compare when the car already wears 19-inch wheels and the owner wants to stay with that configuration.
255/35R20 is a low-profile metric radial size that uses a 255-millimeter nominal section width, a 35-series profile, and a 20-inch rim. On the 2015 Buick Regal, this size belongs to a larger-wheel setup and brings the most visually aggressive fitment of the primary Regal tire sizes. Product choices include BFGoodrich, Nitto, and Pro-Trac, with blackwall options as well as redline and RWL treatments in the Street Pro III series. This is the size to confirm carefully when the car has 20-inch wheels, since wheel width and overall clearance deserve close attention on low-profile applications.
235/50R17 is a metric radial size with a 235-millimeter nominal section width, a 50-series profile, and a 17-inch rim diameter. On the 2015 Buick Regal, it applies to a specific trim and wheel combination, so it should be selected by confirmed vehicle configuration rather than by model name alone. The available product choice in this size centers on a BFGoodrich g-Force Comp 2 AS blackwall radial, keeping the selection straightforward. It is the size to use when the Regal has the 17-inch setup and the priority is staying with the proper wheel diameter and overall fitment approach.
Sub-model fitment matters on the 2015 Buick Regal because tire size is not the same across the entire lineup. Some trims share an 18-inch setup, while others use 17-, 19-, or 20-inch wheel and tire combinations, so identifying the exact Regal version is the first step before comparing products.
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2015 Buick Regal Base
The 2015 Buick Regal Base uses the 235/50R18 radial size, keeping its tire fitment centered on an 18-inch wheel. Tire selection here is mostly about choosing among available brands, tire series, and sidewall styles rather than sorting through multiple primary sizes.
The 2015 Buick Regal GS uses either 245/40R19 or 255/35R20 radials, so wheel diameter has to be confirmed before choosing a tire. That makes the GS the Regal sub-model where checking the actual wheel setup matters most before comparing blackwall, redline, or raised white letter options.
The 2015 Buick Regal Premium Turbo uses the 235/50R18 radial size on an 18-inch setup. Once that fitment is confirmed, the decision shifts to product character and appearance, including blackwall, redline, or RWL treatments in the available 18-inch choices.
The 2015 Buick Regal Premium eAssist uses either 235/50R17 or 235/50R18, so the correct tire depends on which wheel diameter is on the car. That makes wheel verification more important than brand comparison at the start, since both sizes share a similar width but fit different rims.
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 2015 Buick Regal Tires for Sale
Available 2015 Buick Regal tires stay within radial construction but vary meaningfully by size, brand, tire series, and sidewall treatment. BFGoodrich, Nitto, and Pro-Trac choices appear across the Regal range, with blackwall options throughout and redline or RWL styling offered in select 18-inch and 20-inch sizes.
These 2015 Buick Regal tire FAQs focus on the questions that matter most once the exact trim is known: correct tire size, wheel diameter, product selection, sidewall style, and the fitment checks worth making before regular road use.
Tire Size & Fitment
What tire size fits a 2015 Buick Regal?
The 2015 Buick Regal uses four primary tire sizes: 235/50R17, 235/50R18, 245/40R19, and 255/35R20. All of them are radial sizes, but they do not apply across the whole Regal lineup in the same way because fitment changes by sub-model and wheel package.
The practical first step is matching the tire size to the exact Regal trim and the wheels currently on the car. A Base or Premium Turbo points you toward 235/50R18, while GS and Premium eAssist require closer wheel confirmation because those trims can use more than one primary size.
What size rim does a 2015 Buick Regal use?
A 2015 Buick Regal can use 17-inch, 18-inch, 19-inch, or 20-inch rims depending on the specific sub-model and tire size. The primary Regal fitments pair 235/50R17 with a 17-inch rim, 235/50R18 with an 18-inch rim, 245/40R19 with a 19-inch rim, and 255/35R20 with a 20-inch rim.
That wide range means wheel diameter should be confirmed before comparing tire brands or styles. Tire sidewall markings, existing wheel measurements, and the trim level all help narrow it down, especially on GS and Premium eAssist models where more than one primary wheel and tire combination can appear.
Why does the 2015 Buick Regal have more than one tire size?
The 2015 Buick Regal has more than one tire size because tire fitment varies by sub-model and wheel package. Base and Premium Turbo use 235/50R18, GS uses either 245/40R19 or 255/35R20, and Premium eAssist can use either 235/50R17 or 235/50R18.
That means the model name alone is not enough to select tires correctly. A Regal owner should verify the exact trim and actual wheel diameter on the car before ordering replacements, particularly if the vehicle has had wheel changes or if a used Regal was purchased without certainty about its original setup.
Choosing the Right Tire
What should I consider when choosing a 2015 Buick Regal tire?
Start with the correct primary size for the exact 2015 Buick Regal sub-model and wheel diameter, then compare the available radial options within that size. After fitment is confirmed, useful factors include brand, tire series, sidewall style, rim-width compatibility, and whether the car is driven mainly for daily road use or weekend enjoyment.
A Regal on 17- or 18-inch wheels may point you toward a different product mix than a GS on 19- or 20-inch wheels. It also helps to compare visible details such as blackwall, redline, or raised white letter styling if appearance matters as much as maintaining the intended size and wheel relationship.
What sidewall styles are available for 2015 Buick Regal tires?
Sidewall style depends on the Regal’s tire size. Blackwall options appear across all four primary sizes, while redline and RWL choices are available in select 18-inch and 20-inch fitments through Pro-Trac Street Pro III products.
That gives some Regal owners a chance to move beyond a plain blackwall presentation without changing the basic tire size. Sidewall style should still be chosen only after the correct fitment is confirmed, since appearance options differ by size and are not offered uniformly across every 2015 Buick Regal wheel package.
What brands offer tires for the 2015 Buick Regal?
BFGoodrich, Nitto, and Pro-Trac offer tires for the 2015 Buick Regal, depending on the specific size. BFGoodrich appears across the full Regal size range, while Nitto and Pro-Trac are available in selected 18-inch and 20-inch applications.
Brand choice is most useful once the right tire size is settled, because the available mix changes from one Regal fitment to another. A 235/50R17 owner sees a narrower selection than someone shopping 235/50R18 or 255/35R20, where there is more variety in both tire series and sidewall presentation.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2015 Buick Regal?
Yes. Modifications such as aftermarket wheels, suspension changes, lowering, or body alterations can affect tire fitment on a 2015 Buick Regal even when the tire size looks close to stock. The Regal already uses several different factory wheel diameters, so changes to the car can complicate size selection quickly.
A modified Regal should have wheel diameter, wheel width, and clearance checked before new tires are chosen. Steering clearance, inner-fender space, and suspension travel deserve attention as well, especially on 19-inch and 20-inch setups where the sidewall is lower and fitment margins can be less forgiving.
What should I inspect before driving a 2015 Buick Regal on new tires?
Before driving a 2015 Buick Regal on new tires, inspect the wheels for damage, confirm the tire size matches the car’s actual wheel diameter, and make sure inflation is set correctly for the application. It is also smart to look over suspension and steering components so the new tires start on a stable foundation.
Once the car is on the ground, check for any rubbing at full steering lock and during normal suspension movement. A short test drive can reveal vibration, pull, or clearance issues early, which is especially worthwhile if the Regal has different wheels than expected for its trim level or a recent alignment concern.
How often should tires on a 2015 Buick Regal be inspected?
Tires on a 2015 Buick Regal should be inspected regularly for tread wear, cuts, bulges, air loss, and sidewall cracking. A quick visual check before routine driving is worthwhile, and a closer inspection becomes more important if the car is driven infrequently, stored for long periods, or has recently had wheel or suspension work.
Uneven wear can point to alignment or inflation issues before they become expensive problems. Owners should also pay attention to age-related condition, not just tread depth, because even a modern Regal that sees limited mileage can end up riding on tires that look acceptable at a glance but deserve closer evaluation.
