The 2018 Infiniti Q70L sits in the modern luxury-sedan space with the added rear-seat room that defines the long-wheelbase version, blending traditional big-sedan comfort with a more driver-focused personality than many cars in its class. Tire selection on this model starts with confirming which wheel package is on the car, because the Q70L uses either 245/50R18 or 245/40R20 radial tires. That creates two distinct paths in both appearance and product choice, with blackwall, redline, and raised white letter options available depending on size. For a stock or restored-to-spec appearance, wheel diameter and the exact sub-model setup should be checked before choosing a replacement.
Which Tire Size Is Right for The 2018 Infiniti Q70L
The 2018 Infiniti Q70L uses two primary tire sizes, and the first step is confirming whether the car has 18-inch or 20-inch wheels. Both sizes are radial fitments and both appear on the covered Q70L sub-models, so the real decision is matching the tire to the wheel package already on the car and then choosing the preferred series and sidewall style.
245/40R20 is a metric radial size in which 245 is the section width in millimeters, 40 is the aspect ratio, R identifies radial construction, and 20 is the rim diameter in inches. On the 2018 Infiniti Q70L, this size belongs to the 20-inch wheel setup and keeps the selection centered on modern radial performance-oriented tires. Available choices include BFGoodrich, Nitto, and Pro-Trac, with blackwall, raised white letter, and redline sidewall treatments depending on the tire series. This size is the right place to start when the car already wears 20-inch wheels and the goal is to stay with that wheel and tire package.
245/50R18 is a metric radial size that uses a 245-millimeter section width, a 50-series profile, radial construction, and an 18-inch rim. For the 2018 Infiniti Q70L, this size corresponds to the 18-inch wheel configuration and offers a different fitment path from the 20-inch setup without changing the vehicle's basic radial tire design. Product choices in this size include Pro-Trac Street Pro III options with raised white letter or redline sidewalls. This size should be considered only after confirming the car's actual wheel diameter, especially on vehicles that may have been changed from the original wheel package.
Tire fitment on the 2018 Infiniti Q70L is straightforward in one sense and still worth checking carefully in another. Both covered sub-models use the same two radial tire sizes, so the key is confirming whether the car has the 18-inch or 20-inch wheel setup before choosing a tire.
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2018 Infiniti Q70L 3.7 Luxe
The 2018 Infiniti Q70L 3.7 Luxe uses the same two radial size paths found across the covered Q70L range, tied to either an 18-inch or 20-inch wheel setup. Tire selection comes down to verifying the wheel diameter on the car and then choosing the preferred sidewall style and tire series within the correct size.
The 2018 Infiniti Q70L 5.6 Luxe follows the same fitment pattern, with both primary radial sizes associated with this sub-model depending on wheel package. That makes wheel confirmation especially important before purchase, followed by comparison of available series and appearance treatments in the matching size.
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 2018 Infiniti Q70L Tires for Sale
Available 2018 Infiniti Q70L tires vary by wheel package, brand, tire series, and sidewall presentation. The 20-inch size includes BFGoodrich, Nitto, and Pro-Trac options in blackwall, raised white letter, and redline form, while the 18-inch size centers on Pro-Trac Street Pro III choices.
These FAQs focus on the exact tire sizes used on the 2018 Infiniti Q70L, how the 18-inch and 20-inch fitments differ, and what to check when comparing brands, sidewall styles, wheel setups, and road-use condition.
Tire Size & Fitment
What tire size fits a 2018 Infiniti Q70L?
The 2018 Infiniti Q70L uses two tire sizes: 245/40R20 and 245/50R18. Both are radial fitments, and both appear on the covered Q70L sub-models, so the correct choice depends on which wheel package is actually installed on the car.
The practical step is to confirm wheel diameter before choosing a replacement tire. A Q70L that has 20-inch wheels needs the 245/40R20 size, while an 18-inch wheel setup uses 245/50R18. That matters even more on cars that may have had wheel changes, because the two sizes are not interchangeable without matching the proper rim diameter.
What size rim does a 2018 Infiniti Q70L use?
A 2018 Infiniti Q70L uses either an 18-inch or 20-inch rim, depending on the tire size on the car. The 245/50R18 tire mounts on an 18-inch rim, while the 245/40R20 tire mounts on a 20-inch rim.
That makes rim diameter the first fitment detail to verify before comparing tires. Looking only at tread width is not enough, because both sizes share the same nominal 245-millimeter width while using different wheel diameters and profiles. Checking the sidewall markings on the current tires or confirming the wheel size directly helps prevent ordering the wrong fitment.
Do all 2018 Infiniti Q70L sub-models use the same tire size?
The covered 2018 Infiniti Q70L sub-models share the same fitment pattern rather than one single tire size. Both the 3.7 Luxe and 5.6 Luxe are associated with 245/40R20 and 245/50R18 radial tires, tied to the wheel package installed on the vehicle.
That means the sub-model name alone does not settle the tire decision. The better approach is to identify the car's actual wheels and confirm whether it is running the 18-inch or 20-inch setup. Once that is established, the choice shifts from basic fitment to comparing available tire series, brands, and sidewall treatments in the correct size.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Infiniti Q70L?
Start with the correct primary size for the wheel package already on the car: 245/40R20 for 20-inch rims or 245/50R18 for 18-inch rims. From there, compare the available radial tire options by brand, tire series, sidewall treatment, and any relevant rim-width or load details shown for the specific product.
The right choice depends on how the Q70L is used and how the owner wants it to look. Some buyers will prefer a clean blackwall presentation, while others may want redline or raised white letter styling. It also helps to confirm whether the car is still on its original wheel setup, since that determines which size group should be considered.
What sidewall styles are available for 2018 Infiniti Q70L tires?
Sidewall choices for the 2018 Infiniti Q70L include blackwall, redline, and RWL, or raised white letter, depending on tire size and series. The 20-inch fitment offers the widest appearance range, while the 18-inch size is available in Pro-Trac Street Pro III with redline and RWL styling.
That variety lets the tire shape the car's presentation as much as its fitment. A blackwall suits a more understated modern look, while redline or raised white letter sidewalls create a more custom or enthusiast-oriented appearance. The key is keeping the correct size tied to the correct wheel diameter first, then selecting the sidewall style that matches the car's overall theme.
What brands offer tires for the 2018 Infiniti Q70L?
Tires for the 2018 Infiniti Q70L are available from BFGoodrich, Nitto, and Pro-Trac. Brand choice varies by size, with the 20-inch 245/40R20 fitment offering options from all three, while the 18-inch 245/50R18 fitment centers on Pro-Trac.
That makes size confirmation important before comparing brands. A buyer shopping the 20-inch setup can look across multiple series such as g-Force Comp 2 AS, g-Force Phenom T/A, Nitto NT555 G2, and Street Pro III, while the 18-inch setup is a narrower comparison focused more on sidewall style than on brand spread.
Restoration & Appearance
Which tire should I choose for a period-style 2018 Infiniti Q70L?
A period-style 2018 Infiniti Q70L tire choice starts with retaining the correct modern radial size for the wheel package already on the car, either 245/50R18 or 245/40R20. After that, appearance becomes the main variable, especially where Pro-Trac Street Pro III options offer redline or raised white letter sidewalls.
For a more understated luxury-sedan presentation, a blackwall tire may suit the car better, especially on the 20-inch setup where blackwall options are available. For a more personalized or enthusiast look, redline and RWL styles add visual character without changing the core size. Matching the sidewall treatment to the car's overall theme usually matters more here than chasing a strict restoration formula.
How does tire construction affect the appearance of a restored 2018 Infiniti Q70L?
On the 2018 Infiniti Q70L, construction does not create a bias-ply versus radial decision because the primary fitments are radial tires. The appearance difference comes more from sidewall style, tire series, and the visual relationship between the tire profile and the 18-inch or 20-inch wheel package.
That means a restoration-minded owner is mainly choosing how modern or how customized the finished car should look. Blackwall tires keep the presentation more restrained, while redline or raised white letter versions make the tire itself part of the styling statement. Keeping the correct size on the correct rim diameter preserves the intended proportions better than changing appearance alone.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Infiniti Q70L?
Yes, modifications can affect tire fitment on a 2018 Infiniti Q70L, especially if the car has aftermarket wheels, suspension changes, or altered ride height. Since this model uses either 245/50R18 or 245/40R20 depending on wheel package, any change to wheel diameter or width can alter what size is appropriate.
Even when the tire size printed on the car looks familiar, wheel width, offset, and clearance around the fenders and suspension still matter. A Q70L that has been lowered or fitted with non-original wheels should be checked closely before replacement. That helps avoid rubbing, improper seating on the rim, or choosing a tire that does not suit the modified setup.
What should I inspect before driving a 2018 Infiniti Q70L on new tires?
Before driving a 2018 Infiniti Q70L on new tires, confirm that the tire size matches the wheel diameter, inspect the wheels for damage, and make sure the tires are properly seated and inflated. It is also smart to look over tread surfaces and sidewalls for shipping damage, cuts, or irregularities before road use.
A short follow-up inspection after the first drive is worthwhile, especially to verify air retention and look for any signs of rubbing or contact. On a car with 18-inch or 20-inch fitment choices, this matters because installing the correct size still does not rule out issues from prior wheel changes or suspension wear. Early checks help catch small problems before they become driving issues.
How often should tires on a 2018 Infiniti Q70L be inspected?
Tires on a 2018 Infiniti Q70L should be inspected regularly, not just when tread looks worn. A quick visual check for uneven wear, sidewall cracking, punctures, bulges, and air loss is a good habit, especially on a sedan that may alternate between daily use and longer periods of sitting.
Regular inspection matters even more when the car has optional wheel packages or custom-style sidewall treatments that encourage owners to focus on appearance more than condition. Checking pressure, tread wear pattern, and overall age helps preserve ride quality and catch problems before a longer trip. Any sign of vibration, repeated pressure loss, or edge wear deserves closer attention right away.
