Infiniti M56 Tires

Infiniti M56 uses two tire sizes across the 2011 to 2013 model span: 245/50R18 and 245/40R20. The 245/50R18 size is built for 18-inch wheels, while the 245/40R20 size is built for 20-inch wheels. Both sizes appear in each model year rather than being split into early and late production.

That means the correct tire is determined by the wheel package on the specific Infiniti M56, not by year alone. Start by reading the size on the current tire or confirming the wheel diameter directly, then choose the matching size rather than assuming all 2011, 2012, or 2013 cars use the same fitment.

On an Infiniti M56, 245/50R18 is a metric radial size. The 245 is the section width in millimeters, 50 is the aspect ratio that describes sidewall height relative to width, R identifies radial construction, and 18 is the wheel diameter in inches. It is one of the two wheel-package sizes used on the model from 2011 through 2013.

Reading the code correctly helps prevent one of the most common collector and enthusiast mistakes on newer performance sedans: matching the width but missing the wheel diameter. If your Infiniti M56 is on 18-inch wheels, this is the size family to focus on, and then you can decide whether blackwall, RWL, or redline styling best suits the car.

A 2011 Infiniti M56 has two tire sizes listed because the model was offered with two wheel diameters in the same year. One setup uses 245/50R18 on 18-inch wheels, and the other uses 245/40R20 on 20-inch wheels. The same split continues through 2012 and 2013.

That kind of overlap is a wheel-package split rather than a midyear production change. If your Infiniti M56 still carries its original wheels, the wheel diameter will identify the correct tire immediately; if the wheels have been changed, measure or verify the actual rim size before choosing a replacement.

Infiniti M56 uses either an 18-inch or a 20-inch rim diameter. The 245/50R18 fitment is tied to 18-inch wheels, and the 245/40R20 fitment is tied to 20-inch wheels. Both rim diameters were used throughout the full 2011 to 2013 production span.

Because both diameters exist in the same years, the wheel itself is the deciding factor. Check the size molded into the current tire sidewall or verify the wheel diameter directly before replacing tires, especially on cars that may have had wheel changes during ownership.

A 2012 Infiniti M56 can use either 245/50R18 or 245/40R20, depending on which wheel package the car has. The first size belongs to an 18-inch wheel, and the second belongs to a 20-inch wheel. Year alone does not separate them, because both were used in 2012.

The quickest check is to read the sidewall on the current tire and confirm that the wheel diameter matches the last number in the size code. If the car has aftermarket wheels or a mixed set, verify all four corners carefully before replacing anything so the new tires match the actual wheel size and intended setup.

Infiniti M56 tire options include Blackwall, RWL, and Redline sidewall styles. Blackwall choices appear in the 245/40R20 size, while RWL and Redline versions are offered in both 245/50R18 and 245/40R20. That gives owners a choice between a more understated modern look and a more visual performance-oriented appearance.

For a factory-leaning presentation on a modern luxury sport sedan, blackwall is usually the most restrained choice. RWL or redline can work if the goal is a more custom or enthusiast look, but it is wise to choose the sidewall style after confirming the correct size and wheel diameter for the specific Infiniti M56.

Current Infiniti M56 tire options in these sizes come from Pro-Trac, BFGoodrich, and Nitto. Pro-Trac appears in both listed sizes, while BFGoodrich and Nitto are represented in the 245/40R20 fitment. That gives the M56 a mix of styling-focused and performance-oriented radial choices.

Brand selection matters once the size and wheel diameter are settled. An owner focused on visual presentation may lean toward the available sidewall-style options, while an owner keeping an Infiniti M56 in regular road use may compare the modern 20-inch performance-oriented offerings more closely within the correct fitment.

Infiniti M56 tires here appear in several series, including Street Pro III, g-Force Comp 2 AS, g-Force Phenom T/A, and Nitto NT555 G2. All are radial designs, but they represent different product families with different intended character, from styling-driven options with RWL or redline sidewalls to more contemporary performance street patterns in blackwall form.

The practical way to sort them is to decide what matters most on your Infiniti M56: period-style visual flair, a cleaner OE-like look, or a more modern performance-tire presentation. Once you have the correct 18-inch or 20-inch fitment identified, compare series within that size rather than across sizes.

An Infiniti M56 should be stored on clean, properly inflated tires in a cool, dry, and dark environment away from ozone sources such as electric motors, welders, and battery chargers. Keeping the car out of direct sunlight and away from chemicals that can affect rubber will slow visible and internal aging. Long static periods can also create temporary or permanent flat spotting.

If the Infiniti M56 will sit for extended periods, move it occasionally or support it in a way that reduces constant load on one contact patch. Good storage habits matter whether the car wears 18-inch or 20-inch tires, because low-use collector and enthusiast vehicles often age their tires out long before they wear them out.

Tires on an Infiniti M56 should be inspected regularly even if the car is driven only occasionally. Look for uneven wear, sidewall cracking, punctures, bulges, vibration, and changes in air retention, and inspect both the tread surface and the inner sidewall where possible. A performance-oriented sedan can hide alignment or suspension issues in tire wear long before they become obvious from casual driving.

A good routine is to inspect the tires before any extended drive and during seasonal service. On an Infiniti M56 with stagger-free but wheel-package-dependent sizing, regular inspections also help confirm that all four tires remain matched in size, construction, and overall condition after rotations, storage periods, or wheel changes.

Tires on an Infiniti M56 should be replaced when age, cracking, impact damage, bulges, repeated air loss, or internal deterioration make them questionable, even if the tread still looks usable. Collector and enthusiast cars often accumulate little mileage, so tread depth alone is not a reliable measure of serviceability. Time, storage conditions, and heat cycles all matter.

If an Infiniti M56 has older tires that look visually acceptable but feel hard, vibrate, or show weather checking, replacement should move ahead of cosmetic concerns. This is especially important on a V8 luxury sport sedan, where weight and performance can place more demand on an aging tire than casual local driving might suggest.

Infiniti M56 appears with two original-equipment-style fitment paths in this year range: 245/50R18 on 18-inch wheels and 245/40R20 on 20-inch wheels. Both sizes were used from 2011 through 2013, so there is no single one-size answer that applies to every M56. The wheel package on the specific car determines which size belongs on it.

For an authenticity-minded owner, the best approach is to verify the wheel package the car was built or long maintained with, then keep the tire size aligned to that setup. Restoring the correct overall look also involves choosing the sidewall treatment carefully, since blackwall, RWL, and redline options create noticeably different visual impressions.

Correct tire fitment can affect how an Infiniti M56 is viewed by knowledgeable buyers, judges, and marque enthusiasts, even though it is a modern performance luxury sedan rather than an antique restoration subject. Using the proper 18-inch or 20-inch size preserves the intended stance, sidewall proportion, and overall presentation of the car. An obviously incorrect diameter or profile changes that appearance quickly.

Owners pursuing preservation-level accuracy should match the tire size to the proper wheel package first, then choose sidewall styling that suits the car's intended character. For show presentation or enthusiast resale, consistency across all four corners usually matters more than chasing a dramatic visual style that conflicts with the wheel package.

Infiniti M56 tire choices here include Blackwall, RWL, and Redline sidewall styles. Blackwall is the most restrained and most in keeping with the way modern premium sport sedans are usually presented, while RWL and redline introduce a more customized or enthusiast-oriented look. The available sidewall choices differ somewhat by size, with blackwall shown in 245/40R20 and RWL or redline available in both listed sizes.

If the goal is a near-factory visual impression, blackwall is the safest direction. If the goal is a personalized presentation for meets or casual use, RWL or redline can be appropriate, but the first priority should still be the correct wheel diameter and tire size for the specific Infiniti M56.

The listed Infiniti M56 tires are modern radial designs intended for road use when they are the correct size for the wheel, properly mounted, correctly inflated, and in sound condition. The key safety point is that the M56 does not use a single universal fitment, so a tire sized for an 18-inch wheel cannot be substituted onto a 20-inch wheel, or the reverse. Proper match matters before any other consideration.

Safe road use begins with confirming the wheel diameter on the car, then using a matched set of tires with even wear and proper condition. Because Infiniti M56 is a powerful sedan, any vibration, pull, impact damage, or visible sidewall distress deserves attention before regular road driving resumes.

Before driving an Infiniti M56, inspect inflation pressure, visible tread and sidewall condition, and basic wheel-to-tire match. Confirm that all four tires are the correct size for the wheels fitted to the car, and check for cuts, bulges, punctures, or uneven wear that could point to alignment or suspension issues. On 20-inch fitments, also verify that the tire remains within the appropriate wheel-width range where specified.

A short walk-around catches most obvious problems before they become roadside failures. If the Infiniti M56 has been stored, recently serviced, or had wheels swapped, spend extra time confirming that all four corners use the intended tire size and that there is no age-related cracking or damage hidden on the inner sidewalls.

An appropriate speed for an Infiniti M56 depends on using the correct tire size, a healthy tire in good condition, and an overall vehicle setup that is mechanically sound. The M56 is a capable high-performance luxury sedan, but no tire should be pushed beyond its condition, inflation state, or suitability for the wheel it is mounted on. Tire age and condition matter as much as the size itself.

For real-world driving, treat the tires as part of the complete condition of the car rather than as a license to use maximum performance at all times. If the Infiniti M56 is on older tires, has spent long periods in storage, or shows any vibration or uneven wear, moderate use and a careful inspection are wiser than testing the car's upper-speed capability.