The 2015 Infiniti Q70 sits in the modern luxury-sport sedan category, blending rear-drive proportions, strong road manners, and the understated design language Infiniti used for its flagship four-door cars in this era. For tire selection, the key question is not bias-ply versus radial, because the Q70 uses radial fitments throughout, but which of its two primary sizes matches the car’s exact setup. The main choices center on 245/50R18 and 245/40R20, with available tires spanning blackwall, raised white letter, and redline sidewall treatments across several series and brands. Before choosing, confirm the sub-model and wheel diameter so the tire matches both the vehicle’s appearance and its actual wheel package.
Which Tire Size Is Right for The 2015 Infiniti Q70
The 2015 Infiniti Q70 uses two primary tire sizes, and the first step is confirming wheel diameter. Both sizes are radial constructions, but one fits an 18-inch wheel and the other fits a 20-inch wheel, so choosing correctly starts with identifying the car’s exact wheel setup and sub-model. Once that is settled, the real decision becomes sidewall style, brand, and tire series within the proper size.
A 245/40R20 tire uses a 245-millimeter section width, a 40-series aspect ratio, radial construction, and a 20-inch rim. On the 2015 Infiniti Q70, this size belongs to cars equipped with the 20-inch wheel setup and keeps the selection focused on modern radial performance-style tires. Available choices include BFGoodrich, Nitto, and Pro-Trac options, with blackwall, RWL, and redline sidewall treatments represented across series such as g-Force Comp 2 AS, g-Force Phenom T/A, and Street Pro III. This size is the one to evaluate when the car already wears 20-inch wheels and the goal is matching that wheel package with the right overall style.
A 245/50R18 tire carries the same 245-millimeter nominal width as the 20-inch fitment, but with a taller 50-series sidewall on an 18-inch rim. For the 2015 Infiniti Q70, this is the radial size used on the 18-inch wheel configuration and it is also the sole listed fitment for the Hybrid sub-model. Current choices in this size center on Pro-Trac Street Pro III tires with RWL and redline sidewall styles. This is the size to confirm when the car has 18-inch wheels and the buyer wants to stay with the proper rim diameter while choosing between appearance-focused sidewall treatments.
Sub-model fitment matters on the 2015 Infiniti Q70 because not every version uses the same tire-size range. The 3.7 and 5.6 can use either 18-inch or 20-inch fitments, while the Hybrid is tied to the 18-inch setup, making wheel and sub-model confirmation the first step before comparing tires.
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2015 Infiniti Q70 3.7
The 2015 Infiniti Q70 3.7 uses either of the two radial tire sizes offered for this model, depending on whether the car has 18-inch or 20-inch wheels. Tire selection starts with confirming the actual wheel package, then narrowing the choice by sidewall style, brand, and tire series within the correct size.
The 2015 Infiniti Q70 5.6 also spans both primary radial fitments, so the same model can appear with either 18-inch or 20-inch wheels. That makes wheel-diameter verification especially important before comparing available products or choosing between a more understated blackwall look and more distinctive sidewall styling.
The 2015 Infiniti Q70 Hybrid uses the 18-inch radial fitment rather than both wheel-size options. For this sub-model, the decision is less about identifying between two primary sizes and more about choosing the preferred sidewall presentation within the proper 245/50R18 setup.
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 2015 Infiniti Q70 Tires for Sale
Available 2015 Infiniti Q70 tires cover both primary sizes, with BFGoodrich, Nitto, and Pro-Trac offerings depending on wheel diameter. Buyers can compare blackwall, RWL, and redline sidewalls along with series such as g-Force Comp 2 AS, g-Force Phenom T/A, NT555 G2, and Street Pro III.
Tire questions for the 2015 Infiniti Q70 usually come down to size selection, wheel diameter, sub-model differences, and choosing between available brands, series, and sidewall styles. The answers below focus on exact fitment, product comparison, and practical checks before road use.
Tire Size & Fitment
What tire size fits a 2015 Infiniti Q70?
The 2015 Infiniti Q70 uses two primary tire sizes: 245/40R20 and 245/50R18. Both are radial sizes, but they do not fit the same wheel diameter, so they are tied to different wheel packages rather than being interchangeable versions of the same setup.
The 3.7 and 5.6 sub-models can use either size depending on the wheel package, while the Hybrid uses 245/50R18. A quick check of the existing wheel diameter is the easiest way to narrow the choice, especially if the car has changed hands or has had wheel changes during its life.
What size rim does a 2015 Infiniti Q70 use?
A 2015 Infiniti Q70 uses either an 18-inch rim or a 20-inch rim, depending on configuration. The 245/50R18 fitment belongs to the 18-inch setup, and the 245/40R20 fitment belongs to the 20-inch setup.
Wheel diameter should be confirmed before ordering tires because the two sizes are not substitutes for one another. Looking only at tread width can be misleading, since both fitments use a 245-millimeter width while changing sidewall profile and rim diameter to suit different wheel packages.
Do all 2015 Infiniti Q70 sub-models use the same tire size?
No. The 2015 Infiniti Q70 3.7 and 5.6 can use either 245/50R18 or 245/40R20, while the Q70 Hybrid uses 245/50R18. That means fitment is not uniform across every Q70 sub-model and wheel combination.
This matters most when a buyer assumes the model name alone is enough to choose a tire. Checking the exact sub-model and the actual wheel diameter avoids ordering the wrong size, especially on used cars that may have optional wheels or aftermarket replacements that changed the original setup.
Choosing the Right Tire
What should I consider when choosing a 245/40R20 tire for a 2015 Infiniti Q70?
Start with the correct size and wheel package, then compare the available radial options by brand, tire series, sidewall style, and rim-width specification where stated. In 245/40R20, the Q70 has choices from BFGoodrich, Nitto, and Pro-Trac, including blackwall, RWL, and redline presentations.
The best way to narrow the field is to decide whether the goal is a more understated modern look or a more distinctive sidewall treatment. It also helps to compare wheel-width compatibility on the existing rims and review load and other product details when the car sees regular road use.
What sidewall styles are available for 2015 Infiniti Q70 tires?
Sidewall choices for the 2015 Infiniti Q70 include blackwall, RWL, and redline, depending on tire size and product line. The 20-inch fitment has the broadest variety, while the 18-inch fitment centers on RWL and redline versions of the Pro-Trac Street Pro III.
Sidewall style is mainly an appearance decision once the correct tire size is confirmed. Blackwall keeps the presentation subtle and contemporary, while RWL and redline create a more assertive look, so the right choice depends on whether the car is being kept visually stock-leaning or personalized.
What brands offer tires for the 2015 Infiniti Q70?
The 2015 Infiniti Q70 has available tire options from BFGoodrich, Nitto, and Pro-Trac. Brand availability depends on size, with the 245/40R20 fitment showing the widest spread and the 245/50R18 fitment focusing on Pro-Trac offerings.
Brand is only one part of the decision, since each option should still be matched to the correct wheel diameter and preferred sidewall treatment. Comparing by series and appearance often helps more than comparing by brand name alone, especially when the car’s intended use is street driving rather than display.
Restoration & Appearance
Which tire should I choose for a period-style 2015 Infiniti Q70?
A period-style 2015 Infiniti Q70 tire choice starts with keeping the correct primary size for the car’s wheel package, then selecting a sidewall that matches the look you want. Blackwall gives the most restrained modern-luxury presentation, while RWL and redline introduce a more customized visual character.
Because this is a modern luxury sedan rather than an early collector car, appearance choices are more about maintaining the car’s era-appropriate presence than chasing exact historical originality. Staying with the proper 18-inch or 20-inch fitment helps preserve the Q70’s proportions while still allowing personal preference in sidewall style.
How does tire construction affect the appearance of a restored 2015 Infiniti Q70?
On the 2015 Infiniti Q70, construction is straightforward because the primary fitments are radial tires. That means the appearance difference comes less from bias-ply versus radial questions and more from tire series and sidewall presentation within the correct radial size.
A blackwall radial keeps the sedan’s look clean and understated, while RWL or redline versions create a more noticeable visual statement. Buyers focused on preserving the car’s original character should pay close attention to wheel diameter, sidewall profile, and overall presentation so the finished stance still suits the Q70’s design.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2015 Infiniti Q70?
Yes. On a 2015 Infiniti Q70, aftermarket wheels, suspension changes, or previous owner upgrades can affect which tire size actually belongs on the car. That is especially important here because the Q70 uses both 18-inch and 20-inch fitments depending on setup.
A modified car should be checked for actual wheel diameter and width before any tire is selected. Clearance at the fenders and during steering travel also matters, particularly if the ride height has been altered, since a tire that matches the factory size code may still need confirmation against the current configuration.
What should I inspect before driving a 2015 Infiniti Q70 on new tires?
Before driving a 2015 Infiniti Q70 on new tires, confirm that all four tires match the intended size, inspect the wheels for damage, and verify proper inflation. It is also smart to look over valve stems, tread seating, and general condition after mounting.
Roadworthiness depends on more than the tire alone, so the first drive should also include a quick check for rubbing, vibration, or pulling. Even on a newer luxury sedan, worn suspension parts or damaged wheels can affect how a fresh set of tires behaves once the car is back on the road.
How often should tires on a 2015 Infiniti Q70 be inspected?
Tires on a 2015 Infiniti Q70 should be inspected regularly for air pressure, tread wear, cuts, bulges, and sidewall damage. Cars that spend long periods parked still deserve routine checks, since age and storage conditions can affect tire condition even when mileage stays low.
Inspection becomes even more important if the car uses larger 20-inch wheels, because low-profile tires make visible damage and pressure changes worth catching early. A quick walk-around before longer drives helps spot uneven wear or clearance issues before they become a larger problem on the road.
