The 2020 Cadillac CT5 arrived as a modern rear-drive sport sedan that blended Cadillac luxury with sharper handling and a more athletic stance than traditional full-size American sedans. That mix of comfort, appearance, and performance makes tire selection especially important, because the CT5 uses three different primary radial sizes across its sub-model range: 245/45R18, 245/40R19, and 255/35R20. Choices within those sizes include touring-oriented and performance-oriented radial lines, along with blackwall, raised white letter, and redline sidewall treatments in selected fitments. The key is matching the exact size to the specific CT5 trim and wheel package before comparing style, series, and intended road use.
Which Tire Size Is Right for The 2020 Cadillac CT5
The 2020 Cadillac CT5 uses three primary tire sizes, and the right one depends on the exact sub-model and wheel setup. These are all radial fitments, but they span 18-inch, 19-inch, and 20-inch rims, so confirming the specific trim and actual wheel diameter should come first. Once that is settled, the decision shifts to tire series, sidewall style, and the balance between appearance and driving use.
Fit(s): Luxury, Premium Luxury (AWD), and Premium Luxury (RWD)
Construction: Radial|Rim: 18 in
245/45R18 is a metric radial size with a 245-millimeter nominal section width, a 45-series aspect ratio, and fitment for an 18-inch rim. On the 2020 Cadillac CT5, this size suits covered configurations that use the taller 18-inch package and keeps the selection firmly in modern radial construction. Available choices include BFGoodrich and Nitto lines, primarily in blackwall form, with series such as g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, and NT555 G2. This size is the one to evaluate when your CT5 is equipped with 18-inch wheels and you want to compare series character and rim-width compatibility within that fitment.
Fit(s): Luxury, Premium Luxury (AWD), Premium Luxury (RWD), Sport (AWD), Sport (RWD), V (AWD), and V (RWD)
Construction: Radial|Rim: 20 in
255/35R20 is a metric radial size that uses a 255-millimeter nominal section width, a lower 35-series profile, and a 20-inch rim diameter. For the 2020 Cadillac CT5, this size appears on covered configurations with the larger 20-inch wheel setup and brings a distinctly modern, low-profile fitment. Product choices include BFGoodrich, Nitto, and Pro-Trac, with blackwall options as well as raised white letter and redline sidewall treatments in the Street Pro III series. This is the size to confirm carefully when appearance matters, since wheel diameter, sidewall profile, and sidewall styling all play a visible role.
Fit(s): Premium Luxury (AWD), Premium Luxury (RWD), Sport (AWD), Sport (RWD), V (AWD), and V (RWD)
Construction: Radial|Rim: 19 in
245/40R19 is a metric radial size with a 245-millimeter nominal section width, a 40-series profile, and fitment for a 19-inch wheel. On the 2020 Cadillac CT5, it serves configurations that use the 19-inch package and sits between the 18-inch and 20-inch fitments in wheel diameter and sidewall profile. Available options center on BFGoodrich blackwall tires in g-Force Sport Comp 2, g-Force Comp 2 AS, and g-Force Phenom T/A series. This size deserves close attention if your CT5 carries 19-inch wheels, because the correct rim diameter and the intended series choice matter more here than sidewall-style variation.
Tire fitment on the 2020 Cadillac CT5 varies by sub-model, so identifying the exact trim is an important first step. Some versions share more than one possible size, while others are tied to 19-inch and 20-inch combinations that make wheel confirmation especially important.
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2020 Cadillac CT5 Luxury
The 2020 Cadillac CT5 Luxury uses 245/45R18 and 255/35R20 radial tire fitments, so the actual wheel package on the car needs to be confirmed before choosing a tire. Once wheel diameter is verified, selection comes down to comparing available radial series and the sidewall treatments offered in the applicable size.
The 2020 Cadillac CT5 Premium Luxury (AWD) spans 245/45R18, 245/40R19, and 255/35R20 radial fitments, making wheel diameter the key detail to verify first. That broader fitment range means tire selection is less about one universal size and more about matching the installed wheel package before comparing series and styling.
The 2020 Cadillac CT5 Premium Luxury (RWD) can use 245/45R18, 245/40R19, or 255/35R20 radial tires depending on wheel setup. Because three rim diameters are involved, the smartest approach is to confirm the wheels on the car first and then compare the available product lines within the matching size.
The 2020 Cadillac CT5 Sport (AWD) uses 245/40R19 and 255/35R20 radial tire fitments across the covered setups. That makes wheel diameter the deciding factor first, followed by whether the goal is a straightforward blackwall presentation or one of the available performance-style sidewall options in the 20-inch size.
The 2020 Cadillac CT5 Sport (RWD) uses 245/40R19 and 255/35R20 radial sizes rather than the 18-inch fitment. Tire choice starts with confirming whether the car is on 19-inch or 20-inch wheels, then narrowing the selection by tire series and, in the 20-inch size, by visible sidewall style.
The 2020 Cadillac CT5 V (AWD) uses 245/40R19 and 255/35R20 radial tire sizes, so it is important to match the tire to the actual wheel package rather than the model name alone. With that confirmed, the main comparison points become rim-width compatibility, tire series, and the appearance differences available in selected 20-inch products.
The 2020 Cadillac CT5 V (RWD) also uses 245/40R19 and 255/35R20 radial fitments, which makes wheel verification essential before ordering or mounting tires. After the size is confirmed, the decision turns to which available series and sidewall presentation best suit the car's look and intended use.
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 2020 Cadillac CT5 Tires for Sale
Available 2020 Cadillac CT5 tires center on modern radial performance lines from BFGoodrich, Nitto, and Pro-Trac. Depending on size, buyers can compare blackwall options across several g-Force and NT555 G2 series, with raised white letter and redline sidewall treatments also appearing in selected 255/35R20 fitments.
Tire questions for the 2020 Cadillac CT5 usually come down to identifying the correct size by sub-model and wheel package, then comparing radial series, sidewall treatments, and basic fitment checks before road use.
Tire Size & Fitment
What tire size fits a 2020 Cadillac CT5?
The 2020 Cadillac CT5 uses three primary tire sizes: 245/45R18, 245/40R19, and 255/35R20. All three are radial fitments, but they do not apply universally across every CT5 configuration, because sub-model and wheel package determine which size belongs on the car.
The practical first step is to confirm the exact trim and the actual wheel diameter on the vehicle. A CT5 Luxury can differ from a Sport or V configuration, and Premium Luxury versions can span more than one wheel size, so the correct choice starts with the wheel and sub-model rather than the body style alone.
What size rim does a 2020 Cadillac CT5 use?
A 2020 Cadillac CT5 can use 18-inch, 19-inch, or 20-inch rims depending on sub-model and wheel package. The 245/45R18 tire fits an 18-inch rim, the 245/40R19 fits a 19-inch rim, and the 255/35R20 fits a 20-inch rim.
Rim diameter is the quickest way to narrow the correct tire size on this car. Checking the wheel itself or the tire already mounted on the vehicle helps prevent choosing a tire that matches the model name but not the actual setup, especially on trims that appear with more than one wheel package.
Do all 2020 Cadillac CT5 sub-models use the same tire size?
No. The 2020 Cadillac CT5 does not use one universal tire size across all sub-models. Luxury, Premium Luxury, Sport, and CT5 V configurations can use different combinations of 245/45R18, 245/40R19, and 255/35R20 depending on the trim and wheel package.
That variation means the model badge alone is not always enough to select tires accurately. A Premium Luxury version can span three fitments, while Sport and V versions focus on 19-inch and 20-inch sizes, so matching the tire to the exact sub-model and installed wheel diameter is the safest way to avoid a mismatch.
Choosing the Right Tire
What should I consider when choosing a 2020 Cadillac CT5 tire?
Start with the correct size for the exact CT5 sub-model and wheel diameter, then compare the available radial tire series within that fitment. The 2020 Cadillac CT5 spans 18-inch, 19-inch, and 20-inch applications, so choosing the right size comes before comparing brand, sidewall style, or load-related specifications.
After the size is confirmed, focus on how the car is used and what look you want. Some fitments are offered only as blackwalls, while selected 255/35R20 options add raised white letter or redline styling, and rim-width compatibility can matter when the car has alternate wheels within the same nominal diameter.
What sidewall styles are available for 2020 Cadillac CT5 tires?
Sidewall style depends on the tire size. Blackwall options are available across the CT5 fitments, while 255/35R20 also appears with raised white letter and redline sidewall treatments in the Pro-Trac Street Pro III series.
That means appearance choices are broader in the 20-inch fitment than in the 18-inch or 19-inch sizes shown here. Sidewall style does not replace the need to match the correct tire size, but once the fitment is confirmed it can help shape whether the finished look stays understated or leans more toward a custom performance presentation.
What brands offer tires for the 2020 Cadillac CT5?
The 2020 Cadillac CT5 fitments shown here are available from BFGoodrich, Nitto, and Pro-Trac. BFGoodrich appears across all three primary sizes, Nitto is available in 18-inch and 20-inch applications, and Pro-Trac appears in the 255/35R20 size.
Brand choice matters less than getting the exact size and wheel match right first. Once the fitment is settled, the useful comparison points become the series offered in that size, the sidewall treatment available, and whether the tire's rim-width specifications suit the wheel currently on the car.
Restoration & Appearance
Which tire should I choose for a period-style 2020 Cadillac CT5?
A period-style concern on a 2020 Cadillac CT5 is usually less about vintage construction and more about preserving the car's intended modern character. That starts with the correct original-size-style radial fitment for the exact wheel package, whether that is 245/45R18, 245/40R19, or 255/35R20.
Appearance then comes from the tire series and sidewall treatment available in that size. Blackwalls keep the presentation closer to a contemporary OEM-style look, while raised white letter or redline choices in 255/35R20 move the car toward a more personalized visual statement without changing the need for proper wheel and trim-specific fitment.
How does tire construction affect the appearance of a restored 2020 Cadillac CT5?
On a 2020 Cadillac CT5, construction choice is straightforward because the primary fitments are radial. That means the visual differences come less from bias-ply versus radial questions and more from profile, wheel diameter, and sidewall treatment within the radial tires available for the car.
A lower-profile 20-inch setup presents the CT5 differently than an 18-inch package, even before brand or series enters the picture. Buyers concerned with appearance should first match the correct trim and wheel size, then decide whether a blackwall look or a more expressive raised white letter or redline sidewall better suits the finished car.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2020 Cadillac CT5?
Yes. Modifications can affect tire fitment on a 2020 Cadillac CT5 even when the tire size matches one of the correct factory-style sizes. Aftermarket wheels, different wheel widths, offset changes, lowering, or suspension alterations can all change how a 245/45R18, 245/40R19, or 255/35R20 tire sits in the wheel opening.
That is why modified cars should be checked at the wheel, not just by trim name. Clearance at full steering lock, fender room under compression, and wheel width suitability all matter, especially with the lower-profile 19-inch and 20-inch fitments that leave less margin for setup changes than a stock wheel package.
What should I inspect before driving a 2020 Cadillac CT5 on new tires?
Before driving a 2020 Cadillac CT5 on new tires, confirm the exact size matches the wheel diameter, make sure the tires are properly seated and inflated, and inspect for any visible damage or irregularity. It is also wise to verify that the wheel and tire combination clears suspension and body components cleanly.
A careful road-use check should include watching for vibration, rubbing, or unusual steering feel during the first miles. The CT5 uses several wheel diameters across its range, so even a quality new tire needs to be matched to the correct wheel package, especially if the car has different wheels than it left the factory with.
How often should tires on a 2020 Cadillac CT5 be inspected?
Tires on a 2020 Cadillac CT5 should be inspected regularly, not only when tread looks worn. A routine check for air loss, cuts, bulges, irregular wear, and sidewall damage helps catch problems early, and it is especially useful on a car that may switch between seasonal use patterns or spend time parked.
Inspection becomes even more important when the CT5 has performance-oriented low-profile tires, since visible wheel and sidewall damage can be easier to miss until the car is moving. Pressure should be checked consistently, and any sudden change in ride feel, steering response, or noise deserves a closer look before longer highway use.
