2023 Cadillac Tire Fitment Guide

2023 Cadillac vehicles use ten tire sizes across two model lines. The CT4 uses 225/45R17, 235/35R19, 235/40R18, 255/35R18, and 275/35R18, while the CT5 uses 245/45R18, 255/35R20, 245/40R19, 275/35R19, and 305/30R19. Rim diameters span 17 through 20 inches, and rim-width recommendations vary by size, including examples such as 7.0-8.5 inches for 225/45R17, 8.0-9.5 inches for 235/40R18, 9-11 inches for 275/35R19, and 7.5-9.0 inches for 245/45R18.

That means year and make alone are not enough for a correct choice on 2023 Cadillac cars. You need to identify whether you have a CT4 or CT5 and then confirm the exact size already fitted to the wheel position, especially on cars with wider rear tires than front tires. Checking the sidewall of the tire currently on the car is usually the fastest starting point.

On a 2023 Cadillac, 225/45R17 is a metric radial size. The 225 is the nominal section width in millimeters, 45 is the aspect ratio, meaning the sidewall height is 45 percent of the width, R means radial construction, and 17 is the wheel diameter in inches. In this year and make, that size belongs to the CT4 and fits a 17-inch wheel, with product rim-width ranges reaching from 7.0 to 8.5 inches on some options.

Reading the code correctly matters because it tells you far more than just overall size. A 17-inch tire cannot replace an 18- or 19-inch tire without changing wheels, and the lower-profile 35- and 40-series sizes used elsewhere in the 2023 Cadillac range have a very different shape. If your CT4 currently wears 225/45R17, stay with that exact code unless you are intentionally changing the wheel package.

No, 2023 Cadillac models do not share a common tire size. The CT4 and CT5 each use five different sizes, and none of those sizes overlap between the two model lines. The CT4 range runs from 17-inch through 19-inch fitments, while the CT5 range runs from 18-inch through 20-inch fitments, including very wide 19-inch and 20-inch applications on some cars.

That difference is important because two Cadillac sedans from the same year can require completely different wheel diameters and tire widths. A buyer comparing tires across the 2023 Cadillac lineup should treat CT4 and CT5 as separate fitment families, not as interchangeable applications. Once the model is confirmed, the next step is verifying whether the car has a square setup or different front and rear sizes.

Most 2023 Cadillac tire sizes here are available only with blackwall sidewalls, which suits the clean, modern appearance expected on contemporary Cadillac sport sedans. The one clear exception is 305/30R19 for the CT5, where blackwall, RWL, and redline versions are available. That gives the widest CT5 fitment a broader appearance range than the rest of the year-make lineup.

For buyers who want an understated factory-like look, blackwall remains the natural choice across nearly every 2023 Cadillac size. RWL or redline sidewalls on 305/30R19 create a more customized presentation and may appeal more to style-driven builds than to an OEM-style replacement approach. Sidewall style does not replace the need to match the exact size, wheel diameter, and application first.

BFGoodrich and Nitto cover nearly the full 2023 Cadillac size range here, with BFGoodrich appearing in every size and Nitto offered in many of them. Pro-Trac joins the mix on 305/30R19 for CT5 applications, where it offers alternate sidewall treatments in addition to the usual blackwall look. Every size in this year and make uses radial construction, but the brand mix changes slightly depending on the exact size.

That means brand choice is strongest once you know the exact tire code on your Cadillac. A CT4 owner shopping 235/40R18 will see a different mix than a CT5 owner shopping 305/30R19, so it helps to narrow the fitment before comparing series or appearance. If brand heritage matters to you, BFGoodrich brings deep American performance-tire history, while Nitto is well known in modern enthusiast and street-performance circles.

On many 2023 Cadillac sizes, BFGoodrich and Nitto overlap in the same basic fitment but differ in details such as rim-width range, speed rating, and load marking. For example, in 235/40R18, BFGoodrich options include W- and Y-rated choices, while Nitto offers a W-rated option with a load figure of 1,521 pounds at 50 psi. In 275/35R18, BFGoodrich reaches W and Y ratings, while Nitto offers a W-rated XL version with a 1,709-pound load figure at 50 psi.

Those differences matter most when you are matching the tire to the wheel already on the car and to the kind of driving the car sees. Some buyers will focus on sidewall appearance and brand preference, while others will care more about speed rating, load reserve, or the rim-width window the tire is designed around. Compare those details within your exact size rather than assuming one series mirrors another.

Rim-width requirements on 2023 Cadillac tires vary by size. Examples include 7.0-8.5 inches for 225/45R17, 8.0-9.5 inches for 235/40R18 and 245/40R19, 8.5-10.0 inches for 255/35R18 and 255/35R20, 9-11 inches for 275/35R18 and 275/35R19, and 7.5-9.0 inches for 245/45R18. Some sizes appear across more than one series with similar but not always identical rim-width wording.

That is why wheel width should be confirmed before settling on a specific tire, not just before mounting day. A tire may match the sidewall size code and still be a poor choice if the wheel falls outside the maker's approved width range for that exact product. This is especially important on low-profile 18-, 19-, and 20-inch Cadillac applications where wheel and sidewall proportions are tight.

The 2023 Cadillac sizes here are modern radial fitments and the size markings do not show tube-type designations. These applications are treated as tubeless radial products rather than tube-type collector tires. That matches what most buyers would expect on a 2023 Cadillac CT4 or CT5 with modern one-piece road wheels.

Even so, tubeless does not eliminate the need to inspect the wheel itself. The bead seat, valve stem, and wheel condition all have to support an airtight seal, especially on low-profile performance sizes where even small pressure loss can affect handling feel. If the car has aftermarket wheels, verify that the wheel specification matches the tire size and that the valve hardware is in good condition.

Original 2023 Cadillac wheels cannot be treated as universal across the full year-make range because the cars use 17-, 18-, 19-, and 20-inch tire diameters. A 225/45R17 fits only a 17-inch wheel, a 255/35R20 fits only a 20-inch wheel, and the various 18- and 19-inch sizes still differ by width and intended application. Wheel compatibility begins with matching the exact rim diameter, then confirming width.

That matters most on cars with staggered setups, where front and rear tires may share a general profile style but not the same dimensions. A CT5 with 245/40R19 and 275/35R19, for example, still needs the correct wheel width at each end of the car. Treat the original wheel package as part of the fitment, not as a separate item from the tire.

A 2023 Cadillac should be stored in a cool, dry, dark place with the tires protected from sunlight, electric motors, battery chargers, furnaces, and other ozone sources that accelerate rubber aging. Keep the tires properly inflated during storage and move the car periodically so the same contact patch does not sit under load for months at a time. Modern radials resist temporary flat spotting better than old bias-ply tires, but long static storage still stresses the casing and sidewall.

If the car will sit for an extended season, many collectors either roll it occasionally or support it in a way that reduces prolonged loading on one section of the tire. Clean floors, stable temperatures, and avoidance of petroleum contamination also help. Good storage habits preserve not only the tires but also the ride quality and steering feel you expect when the Cadillac goes back on the road.

Tire life on a 2023 Cadillac should be judged by age and condition as much as by tread depth, especially on cars that are driven seasonally or see low annual mileage. A common collector-vehicle rule is to begin careful evaluation around five to seven years of service and to give serious replacement consideration by about ten years, regardless of how much tread remains. The DOT date code on the sidewall is the place to start that age check.

Performance-oriented radial tires can still look usable while their rubber compound and internal structure have aged beyond their ideal service window. Heat cycling, storage conditions, and underinflation history all matter. If your 2023 Cadillac has spent long periods parked, inspect for age-related hardening and sidewall cracking rather than relying on appearance alone or assuming low mileage means long remaining life.

Tires on a 2023 Cadillac should be inspected before every drive and more thoroughly before any longer highway outing. Look for cuts, bulges, punctures, uneven tread wear, sidewall cracking, and pressure loss, and make sure the valve stems are in good shape. On a modern performance sedan with low-profile radials, small changes in pressure or sidewall condition can affect steering response sooner than many drivers expect.

A monthly pressure check is a good routine even when the car is not being used regularly, and an alignment check is wise if inner or outer shoulder wear appears. If the Cadillac runs wider rear tires than front tires, inspect each axle on its own pattern rather than assuming all four tires will wear the same way. Include the spare if the car carries one, since emergency readiness matters too.

Yes, the 2023 Cadillac tires here are modern radial performance sizes suitable for highway use when they are the correct size, properly inflated, and in sound condition. Speed ratings in this range include W, which is rated to 168 mph, and Y, which is rated to 186 mph on applicable products. Those figures are far above normal U.S. highway speeds, so real-world safety usually depends more on correct fitment, tire condition, alignment, and the vehicle's overall mechanical health than on the speed symbol alone.

That does not mean every tire in the same size is interchangeable for every driver's priorities. If you are choosing among W- and Y-rated options in a CT4 or CT5 fitment, match the rating to the vehicle's intended use and stay within the maker's inflation and load guidance. A powerful modern Cadillac sedan deserves the same attention to tire condition as any other performance car before sustained highway driving.

Inflation pressure on 2023 Cadillac tires should follow the vehicle placard or owner's manual first, since factory pressure targets are set for the specific model, axle load, and wheel package. Some tire options in these sizes also carry maximum load figures at 50 or 51 psi, such as 1,477 pounds at 50 psi for some 225/45R17 and 255/35R18 versions, 1,709 pounds at 50 psi for some 275/35R18 versions, and 1,764 pounds at 50 psi for some 245/45R18 and 275/35R19 versions.

Those load-and-pressure figures are tire-rating limits, not a blanket instruction to run every 2023 Cadillac at that pressure. The correct everyday setting is the one specified by Cadillac for your exact CT4 or CT5 configuration unless the tire manufacturer directs otherwise for a special application. Never transfer a pressure figure from one size to another, because the sidewall, load index, and axle role may differ.

Before a longer trip in a 2023 Cadillac, inspect each tire for proper inflation, tread condition, punctures, sidewall cracking, bulges, and any sign of uneven wear. Verify that the front and rear sizes match the wheel positions already on the car, especially if it uses staggered fitments such as different-width 18- or 19-inch tires. The valve stems and any spare tire should be checked at the same time.

A longer-drive inspection should also include the rest of the car, because tires are only one part of the readiness picture on a modern performance sedan. Brake condition, alignment feel, suspension noise, and fluid levels matter just as much once speeds rise and miles add up. Tire-wise, the goal is simple: correct size, stable pressure, sound sidewalls, and no damage that could become a failure under heat and distance.