2020 Buick Tire Fitment Guide

2020 Buick vehicles here use four sizes: 245/40R19, 225/55R17, and 245/45R18 for the Regal Sportback, plus 235/50R18 for the Regal TourX. The 245/40R19 size fits 19-inch rims with product rim-width ranges of 8.0 to 9.5 inches. The 225/55R17 size fits 17-inch rims with ranges from 6.0 to 9.0 inches depending on the tire. The 245/45R18 size fits 18-inch rims with ranges from 7.5 to 9.0 inches, while 235/50R18 fits 18-inch rims with ranges from 6.5 to 8.5 inches.

That means model identification matters first, and wheel diameter matters second. A Regal Sportback can appear with three different sizes depending on the wheel package, while the Regal TourX stays on its own 18-inch fitment. Checking the sidewall on the current tire and confirming the wheel diameter before choosing a replacement is the quickest way to avoid crossing Sportback and TourX sizes.

On a 2020 Buick, 245/40R19 is a metric radial code. The 245 is the nominal section width in millimeters, 40 is the aspect ratio, meaning the sidewall height is 40 percent of the section width, and R identifies radial construction. The final 19 is the wheel diameter in inches, so this size mounts on a 19-inch rim. In this Buick range, 245/40R19 belongs to the Regal Sportback.

That decoding helps separate the tire's physical proportions from the vehicle nameplate. Even within the Regal Sportback family, 19-inch, 18-inch, and 17-inch tire sizes all appear, so the wheel itself determines which code you need. Once the size is confirmed, the next comparison is between available BFGoodrich products and their speed ratings rather than between different size formats.

No. The 2020 Buick Regal Sportback uses 245/40R19, 225/55R17, or 245/45R18 depending on configuration, while the 2020 Buick Regal TourX uses 235/50R18. Every size here is a radial, but the wheel diameters and section widths are not shared across the full model range. That makes 2020 Buick a model-specific fitment year rather than a one-size Buick application.

For buyers, that means year and make are only the starting point. If you know you have a Regal but have not yet confirmed whether it is a Sportback or TourX, or whether it is on 17-, 18-, or 19-inch wheels, you are still one step short of the correct tire choice. Verifying the model badge and reading the existing sidewall together usually resolves that quickly.

Most 2020 Buick sizes here are available only as blackwall radials. The exception is 225/55R17 for the Regal Sportback, which also appears as a BFGoodrich Silvertown Radial with a 1.50-inch wide whitewall. That gives the 17-inch Sportback fitment a much different visual direction than the rest of the Buick range, which stays firmly in contemporary blackwall territory.

If appearance matters as much as fitment, sidewall style becomes part of the decision. A blackwall keeps the look modern and closest to how late-model Buicks were typically presented, while a whitewall introduces a custom or nostalgic visual cue rather than a factory-modern one. The important step is to treat sidewall style as a look choice after the correct size is already confirmed.

2020 Buick sizes here are covered by BFGoodrich and Nitto. BFGoodrich appears in every size, including 245/40R19, 225/55R17, 245/45R18, and 235/50R18, while Nitto appears in the 18-inch sizes 245/45R18 and 235/50R18. Brand coverage is broadest in the 18-inch fitments, where buyers can compare more than one name within the same size.

That brand split is useful when narrowing your search by both size and intended use. If your Buick is on 17-inch or 19-inch wheels, BFGoodrich carries the available fitment range here. If it is on one of the 18-inch sizes, you can compare BFGoodrich and Nitto within the same dimension and then sort further by speed rating, load capacity, and preferred tire series.

For 2020 Buick 245/45R18 fitment, BFGoodrich and Nitto both offer blackwall radials on 18-inch rims. BFGoodrich options span rim-width ranges of 7.5 to 9.0 inches and include products with 96W and 100Y markings, plus load figures up to 1,764 pounds at 50 psi where stated. The Nitto NT555 G2 also fits 7.5 to 9.0-inch rims, carries a 100W marking, and shows a 1,764-pound load figure at 50 psi.

That means the biggest distinctions are in tire series character, speed symbol, and small differences such as weight rather than in basic wheel compatibility. Buyers comparing those 245/45R18 choices should first confirm the wheel is within the stated rim-width range, then decide whether the brand and speed-rating combination better suits how the Regal Sportback will actually be driven.

Rim-width ranges vary by 2020 Buick size. For 245/40R19, the available tires fit 8.0 to 9.5-inch rims. For 225/55R17, the range runs from 6.0 to 9.0 inches depending on the tire chosen. For 245/45R18, the range is 7.5 to 9.0 inches, and for 235/50R18, it is 6.5 to 8.5 inches.

Those ranges matter because two tires with the same size code can still have slightly different approved wheel-width windows. If your wheel falls near the narrow or wide end of the range, it is worth matching it to the specific tire rather than assuming every product in the size behaves the same way. That is especially important when comparing different series within the same 18- or 19-inch fitment.

The 2020 Buick sizes here are modern radial applications, and none of the size markings include tube-type designations. The products use contemporary radial sizing such as 245/40ZR19, 225/55R17, 245/45ZR18, and 235/50ZR18, which are associated with tubeless passenger-car use on appropriate wheels. No separate tube requirement appears within these size groups.

Even so, tube decisions should follow the wheel as much as the tire. If a wheel has been repaired, refinished, or changed from original specification, confirm that its condition and design still support tubeless service. On any late-model Buick wheel and tire combination, a sound valve stem, a clean bead seat, and an undamaged rim are just as important as the tire size itself.

A fitted 2020 Buick stores best in a cool, dry, dark space away from direct sun, electric motors, welders, battery chargers, and other ozone-producing equipment. Keep the tires clean, maintain inflation, and avoid letting the car sit for long periods on a damp surface. Because these are radial tires rather than vintage bias-ply designs, they generally tolerate storage better, but they still age from heat, light, and ozone exposure.

For a Buick that is driven only occasionally, move it periodically or roll it enough to change the tire contact patch. If the car will sit for a very long interval, some owners use stands or tire cradles to reduce stress on one spot. Storage habits make a real difference in how well the sidewalls, tread, and carcass hold up over time, even on a relatively modern collector or low-mileage car.

Tire life on a 2020 Buick is usually judged more by age and condition than by mileage alone, especially on cars that are driven seasonally or sparingly. A good rule is to begin paying close attention once tires are around five to seven years old and to consider replacement around the ten-year mark regardless of tread depth. The DOT date code on the sidewall tells you when the tire was made.

That approach matters because a low-mileage Buick can still wear out its tires through time, heat cycles, and environmental exposure. Hardening rubber, small sidewall cracks, vibration, or a tendency to lose pressure are stronger warning signs than odometer readings by themselves. If the date code is getting older, inspect more often and treat long highway trips more cautiously.

Tires on a 2020 Buick should be checked before every drive and given a more careful inspection before any longer trip. Look for sidewall cracking, uneven tread wear, punctures, cuts, bulges, and signs of impact damage from potholes or curbs. Pressure should be verified cold, and any persistent pressure loss deserves attention even if the tire still looks sound from the outside.

A quick pre-drive walkaround catches many problems before they become roadside issues. On a car that sees mixed weather or seasonal use, also inspect the inner sidewall if possible, since damage there can be easy to miss. Regular inspection is especially worthwhile on 18- and 19-inch fitments, where shorter sidewalls can be less forgiving of road hazards than taller touring-oriented sizes.

The 2020 Buick Regal Sportback was a modern passenger car, so radial tires were the original construction type rather than bias-ply. Within this model range, 225/55R17, 245/45R18, and 245/40R19 are the relevant factory-style sizing families depending on wheel package. No single original-equipment brand should be assumed from size alone, because modern production sourcing can vary by trim, option group, and market.

For an owner trying to keep a Regal Sportback close to original presentation, the key is matching the correct size, wheel diameter, and overall visual character before worrying about brand preference. Blackwall radials are the natural fit for that goal. If absolute delivery-day accuracy matters, a Buick dealer archive, build sheet, or model-specific enthusiast source is the right place to confirm the exact original tire specification.

Yes, correct tire fitment still matters on a 2020 Buick, even though it is a much newer vehicle than the traditional concours era. Judges and knowledgeable enthusiasts will notice obvious differences in size, sidewall style, and overall look, especially if a car appears with a custom whitewall or a wheel-diameter mismatch. On a modern Buick, the expected baseline is a radial tire in the proper metric size for the wheel package.

That does not mean every event demands the same level of originality. A local enthusiast show may welcome personalization, while a marque-focused presentation may favor a more factory-consistent appearance. If your goal is authenticity, stay with the correct size and a period-appropriate blackwall presentation for the model, then consult event rules or Buick-focused communities for how strict that standard will be.

For 2020 Buick 235/50R18 fitment, BFGoodrich and Nitto both offer blackwall radials that mount on 18-inch rims with approved widths from 6.5 to 8.5 inches. BFGoodrich choices include 97W and 101W examples, with load figures up to 1,819 pounds at 50 psi where stated. The Nitto NT555 G2 also carries a 101W marking and shows a 1,819-pound load figure at 50 psi.

From an authenticity standpoint, either brand remains visually aligned with a modern blackwall look, so the deciding factors are more about series preference and exact spec details than appearance. For a Regal TourX owner, the useful next step is to compare the chosen tire's speed symbol, load figure, and rim-width approval against the actual wheel on the car rather than choosing by brand name alone.

Yes, the 2020 Buick tire options here are highway-capable modern radials, and the speed symbols shown are appropriate for normal road use when the tires are in good condition and correctly inflated. W-rated products carry a 112 mph ceiling, while Y-rated products carry a 186+ mph ceiling. Those ratings far exceed ordinary U.S. highway speeds, so condition, inflation, alignment, and the vehicle's overall mechanical health matter more in everyday driving than the upper speed symbol alone.

Safety still depends on using the exact size that belongs on the car and avoiding old, damaged, or underinflated tires. A Regal Sportback on the wrong wheel-and-tire combination or a TourX running a marginally compatible size can create handling and clearance issues even if the tire itself has a high speed rating. Highway confidence comes from correct fitment first, then from proper maintenance and inspection.

Inflation pressure for a 2020 Buick should start with the vehicle placard or owner's manual, because factory pressure targets are set around the car's weight balance and intended ride and handling behavior. Tire ratings in these sizes include examples such as 1,653 pounds at 50 psi for 245/40R19, 1,609 to 1,819 pounds at 50 to 51 psi for 225/55R17 and 235/50R18, and 1,565 to 1,764 pounds at 50 to 51 psi for 245/45R18. Those figures are maximum load-and-pressure references for the tire, not automatic running pressures for the car.

The practical takeaway is simple: do not copy a pressure from one Buick size to another or from one tire's sidewall to the whole model range. Use the car's recommended cold pressure as your baseline, then compare it with the tire manufacturer's limits to stay within safe bounds. If the car has been modified with different wheels, revisit the pressure choice carefully instead of assuming the original setting still applies unchanged.

Before a longer drive in a 2020 Buick, inspect each tire for cracking, punctures, cuts, bulges, unusual wear, and proper cold inflation. Check the spare as well, because a neglected spare is one of the most common weak links on a modern collector or low-use car. If the Buick has been sitting, listen for vibrations on the first few miles and recheck pressure afterward to make sure nothing is slowly leaking.

Tires are only one part of the pre-trip check, but they are one of the easiest to assess before leaving home. A clean bill of health on the sidewalls and tread should be paired with a quick look at brakes, fluids, and battery condition, especially if the car is used intermittently. Taking five extra minutes before departure is much easier than sorting out a preventable tire issue on the shoulder.