The 2019 Cadillac CT6 sits at the modern end of Cadillac’s full-size luxury sedan tradition, blending flagship comfort with sharper road manners and a distinctly contemporary stance. For buyers working with this exact model, tire selection centers on three radial sizes: 235/50R18, 245/45R19, and 245/40R20. Those sizes reflect different wheel packages across the CT6 range, so the first step is confirming the exact sub-model and wheel diameter before comparing tires. Available choices also vary by brand, series, and sidewall presentation, including blackwall, redline, and raised white letter options in some sizes. That makes the decision less about old-versus-new construction and more about matching the car’s wheel setup, intended appearance, and road use.
Which Tire Size Is Right for The 2019 Cadillac CT6
The 2019 Cadillac CT6 uses three primary tire sizes, and the right one depends on the exact sub-model and wheel package. Because those sizes span 18-inch, 19-inch, and 20-inch rims, confirming wheel diameter comes first, followed by sub-model fitment. Once that is settled, the decision shifts to comparing radial tire series, sidewall style, rim-width compatibility, and the overall look you want from the car.
235/50R18 is a modern metric radial size in which 235 identifies nominal section width in millimeters, 50 is the aspect ratio, R denotes radial construction, and 18 is the wheel diameter in inches. On the 2019 Cadillac CT6, this size suits 18-inch wheel applications and keeps the choice within contemporary radial construction rather than a vintage format. Available options include BFGoodrich, Nitto, and Pro-Trac, with blackwall, redline, and RWL presentations across several series. This size is worth evaluating when your CT6 is equipped with 18-inch wheels and you want to balance correct fitment with appearance and product-character differences.
Fit(s): Luxury, Platinum, Platinum 4.2 TT, Premium Luxury, Sport, and V
Construction: Radial|Rim: 20 in
245/40R20 is a metric radial size where 245 is the nominal section width in millimeters, 40 is the aspect ratio, R marks radial construction, and 20 is the required rim diameter. For the 2019 Cadillac CT6, this size is tied to 20-inch wheel fitments and appears across several upper-trim and performance-oriented sub-models. Product choices include BFGoodrich, Nitto, and Pro-Trac, with blackwall options joined by redline and RWL alternatives in the Street Pro III series. It is the size to focus on when the car already wears 20-inch wheels and you want to compare modern tire character with a more distinctive sidewall look.
245/45R19 uses the same nominal 245-millimeter section width as the 20-inch size, but the 45 aspect ratio and 19-inch rim diameter place it in a different fitment category. On the 2019 Cadillac CT6, this radial size belongs to specific 19-inch wheel applications rather than the full model range. Available choices center on blackwall offerings from BFGoodrich and Nitto, including g-Force and NT555 G2 series options. This size deserves attention when your CT6 runs 19-inch wheels and you want to stay with the proper wheel diameter while comparing tire series and rim-width specifications.
Tire fitment on the 2019 Cadillac CT6 varies by sub-model, and some trims can appear with more than one wheel-and-tire package. Checking the exact trim and confirming whether the car has 18-inch, 19-inch, or 20-inch wheels prevents choosing the right size in the wrong diameter.
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2019 Cadillac CT6 Luxury
The 2019 Cadillac CT6 Luxury has the widest fitment spread in this range, with 18-inch, 19-inch, and 20-inch radial tire sizes all appearing under the Luxury name. Tire selection starts with confirming the actual wheel diameter on the car, then comparing product series and sidewall style within that exact size.
The 2019 Cadillac CT6 Platinum uses the 245/40R20 radial size, which keeps fitment focused on a 20-inch wheel setup. That makes tire selection more straightforward, with the main choice shifting to brand, tire series, and whether a blackwall or more expressive sidewall treatment suits the car.
The 2019 Cadillac CT6 Platinum 4.2 TT also uses 245/40R20 radials on a 20-inch rim. With the size already narrowed down, the practical decision becomes choosing among the available radial product lines and deciding whether to keep a restrained blackwall look or explore redline or RWL alternatives.
The 2019 Cadillac CT6 Premium Luxury uses either 245/40R20 or 245/45R19, so wheel diameter must be checked before selecting a tire. Once the car’s actual setup is confirmed, the comparison becomes a matter of staying within the proper radial size and evaluating the available tire series.
The 2019 Cadillac CT6 Sport shares the same two-size situation as Premium Luxury, using either 245/40R20 or 245/45R19 depending on wheel package. Choosing correctly means verifying whether the car has 19-inch or 20-inch wheels first, then comparing the radial options available in that exact fitment.
The 2019 Cadillac CT6 V uses 245/40R20 radial tires, placing it in the 20-inch fitment group. Because there is one primary size here, the next step is comparing available product lines and deciding whether the car should keep a low-key blackwall appearance or take on a more performance-flavored sidewall style.
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 2019 Cadillac CT6 Tires for Sale
Available 2019 Cadillac CT6 tires center on radial choices from BFGoodrich, Nitto, and Pro-Trac across the 18-inch, 19-inch, and 20-inch fitments. Depending on size, buyers can compare blackwall options alongside redline and RWL versions, with series such as g-Force Comp 2 AS, g-Force Phenom T/A, NT555 G2, and Street Pro III.
Tire questions for the 2019 Cadillac CT6 usually come down to exact size, wheel diameter, sub-model fitment, sidewall style, and choosing among available radial product lines. These answers focus on the practical checks that matter before replacing tires on a specific CT6 setup.
Tire Size & Fitment
What tire size fits a 2019 Cadillac CT6?
The 2019 Cadillac CT6 uses three primary tire sizes: 235/50R18, 245/45R19, and 245/40R20. All three are radial sizes, and the correct one depends on the exact CT6 sub-model and wheel package rather than the model name alone.
The most important step is checking the car’s current wheel diameter before choosing a replacement tire. A CT6 equipped with 18-inch wheels cannot use the 19-inch or 20-inch fitments, even though all of them belong to the same model line, so trim level and actual wheel setup both matter.
What size rim does a 2019 Cadillac CT6 use?
A 2019 Cadillac CT6 can use 18-inch, 19-inch, or 20-inch rims, depending on sub-model and wheel package. Those rim diameters correspond to the CT6’s three tire sizes: 235/50R18, 245/45R19, and 245/40R20.
Wheel diameter should be confirmed before anything else because the tire size is built around that measurement. Once the diameter is verified, it becomes much easier to narrow the search to the correct tire and then compare details such as tire series, sidewall style, and rim-width compatibility within that specific fitment.
Why does the 2019 Cadillac CT6 have more than one tire size?
The 2019 Cadillac CT6 has more than one tire size because different sub-models and wheel packages use different rim diameters. The range includes an 18-inch fitment, a 19-inch fitment, and a 20-inch fitment, all within the same model year.
That means the right tire cannot be chosen from the model name alone. Checking the trim badge helps, but the most practical confirmation is looking at the tire sidewall or wheel diameter already on the car, especially on trims such as Luxury, Premium Luxury, and Sport that can appear with multiple fitment combinations.
Choosing the Right Tire
What should I consider when choosing a 2019 Cadillac CT6 tire?
Start with the correct tire size for the exact CT6 wheel package: 235/50R18, 245/45R19, or 245/40R20. From there, compare the available radial options by brand, tire series, sidewall style, and any rim-width or load details that matter to the way the car is equipped and used.
A blackwall tire keeps the look understated, while redline or RWL choices add more visual character where available. It also helps to match the replacement tire to the car’s role, whether that means a cleaner luxury-sedan presentation or a more assertive street-oriented appearance within the proper size.
What sidewall styles are available for 2019 Cadillac CT6 tires?
Sidewall style depends on the tire size. Blackwall options are available across all three CT6 fitments, while redline and RWL choices appear in the 235/50R18 and 245/40R20 sizes through Pro-Trac Street Pro III offerings.
That gives some CT6 owners a visual choice beyond basic size and brand. The key is to treat sidewall style as a finish within the correct fitment, not as a substitute for confirming wheel diameter, because the right appearance still has to be matched to the proper 18-inch, 19-inch, or 20-inch tire size.
What brands offer tires for the 2019 Cadillac CT6?
BFGoodrich, Nitto, and Pro-Trac all offer tires for the 2019 Cadillac CT6 across its supported sizes. Depending on the fitment, the selection includes series such as g-Force Sport Comp 2, g-Force Comp 2 AS, g-Force Phenom T/A, Nitto NT555 G2, and Street Pro III.
Brand choice becomes more useful after the correct size is confirmed, since not every size carries the same mix of styles and series. Some CT6 fitments stay strictly blackwall, while others add redline or RWL options, so the final decision often blends wheel fitment, intended look, and tire-line preference.
Restoration & Appearance
Which tire should I choose for a period-style 2019 Cadillac CT6?
A period-style approach on a 2019 Cadillac CT6 usually starts with staying in the exact original-size family already on the car, whether that is 235/50R18, 245/45R19, or 245/40R20. Since the CT6 is a modern luxury sedan, the appearance decision is less about vintage construction and more about choosing a radial tire that suits the car’s character.
Blackwall tires preserve the most restrained, contemporary luxury-sedan presentation. Redline or RWL options in certain sizes create a more customized look, so buyers aiming for a more showroom-like appearance generally stay conservative, while those building a more personalized CT6 may prefer one of the bolder sidewall treatments.
How does tire construction affect the appearance of a restored 2019 Cadillac CT6?
On the 2019 Cadillac CT6, construction does not create a bias-ply-versus-radial decision because the primary fitments are all radial. The visible appearance difference comes more from sidewall treatment and tire series than from construction type itself.
That makes size accuracy and wheel diameter the first appearance priorities, since an 18-inch, 19-inch, or 20-inch CT6 setup carries a different visual stance. After that, blackwall, redline, or RWL choices can subtly or dramatically change the look without stepping outside the model’s correct radial-tire framework.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2019 Cadillac CT6?
Yes, modifications can affect tire fitment on a 2019 Cadillac CT6. Aftermarket wheels, suspension changes, ride-height adjustments, or body modifications can all change the clearance and wheel specifications that the original 235/50R18, 245/45R19, or 245/40R20 fitments were built around.
Even when the sidewall shows one of the correct CT6 sizes, wheel width and the surrounding space still matter. A modified car should be checked for steering clearance, fender clearance, and actual wheel dimensions before replacement tires are chosen, especially when moving between different tire brands or sidewall-style offerings.
What should I inspect before driving a 2019 Cadillac CT6 on new tires?
Before driving a 2019 Cadillac CT6 on new tires, confirm that the installed size matches the wheel diameter and intended fitment, then inspect inflation, valve condition, and basic clearance around the suspension and body. A quick check for any rubbing points or mounting issues is worthwhile before regular road use.
It also helps to look over the wheels themselves for damage or width mismatch, since CT6 fitments span three different diameters. After the first few drives, recheck pressure and pay attention to any vibration, pull, or contact noise so small setup problems are caught before they become larger wear issues.
How often should tires on a 2019 Cadillac CT6 be inspected?
Tires on a 2019 Cadillac CT6 should be inspected regularly, especially for air pressure, uneven wear, cuts, bulges, and sidewall damage. Even on a newer luxury sedan, those routine checks matter because the CT6 uses low-profile radial sizes that depend on proper inflation and condition for stable road manners.
Monthly visual checks are a sensible habit, with an additional inspection before longer highway trips. Cars that sit for extended periods still deserve attention, since low use can hide pressure loss or age-related issues, and catching those problems early helps protect both the tires and the CT6’s wheel-and-suspension setup.
