Infiniti M37 Tires

Infiniti M37 uses two tire sizes across the 2011 through 2013 model years: 245/50R18 and 245/40R20. The 245/50R18 size fits 18-inch wheels, while the 245/40R20 size fits 20-inch wheels. Both are metric radial sizes and both appear across all three years rather than being tied to an early-versus-late production change.

The practical takeaway is that year alone does not identify the correct tire for Infiniti M37. You need to confirm which wheel package is actually on the car, because an 18-inch tire and a 20-inch tire are not interchangeable. Check the tire sidewall already fitted, the wheel diameter itself, or the vehicle's original equipment label before making your final selection.

On Infiniti M37, the size 245/50R18 breaks down into three key dimensions. The 245 is the nominal section width in millimeters, 50 is the aspect ratio that expresses sidewall height as a percentage of width, and R identifies radial construction. The final number, 18, is the wheel diameter in inches.

That code tells you more than overall fit. A 245/50R18 tire will have a taller sidewall than the 245/40R20 alternative used on some Infiniti M37 models, which changes both the visual proportion and part of the ride character. If your car currently wears 18-inch wheels, this is the size family you should be comparing rather than trying to substitute a 20-inch fitment.

A 2011 Infiniti M37 has two tire sizes listed because the model was offered with two wheel diameters in the same model year. One fitment uses 245/50R18 on 18-inch wheels, and the other uses 245/40R20 on 20-inch wheels. That is a wheel-package split, not a conflict in the model-year listing.

The same logic applies to 2012 and 2013 Infiniti M37 models as well. If you are working from a registration card or a basic year-and-model lookup, that information is not enough by itself to choose a tire. Verifying the wheel diameter on the actual car is the fastest way to separate the two correct fitment paths.

Infiniti M37 uses either an 18-inch or a 20-inch rim diameter in the 2011 to 2013 range covered here. The 245/50R18 size belongs to the 18-inch wheel package, and the 245/40R20 size belongs to the 20-inch wheel package. Both diameters were used during the same years.

That makes wheel verification the first fitment check on any Infiniti M37. Do not assume the correct tire from the year alone, and do not try to match by width only because both sizes begin with 245. Once the wheel diameter is confirmed, the correct tire size follows directly from that measurement.

A 2012 Infiniti M37 can correctly use either 245/50R18 or 245/40R20, depending on which wheels are fitted to the car. The 18-inch wheel setup takes 245/50R18, and the 20-inch wheel setup takes 245/40R20. The same two-way split appears for 2011 and 2013 Infiniti M37 models as well.

Start by reading the size molded into the current tire sidewall, then confirm that it matches the actual wheel diameter. If the car has changed hands or has aftermarket wheels, look closely rather than relying on memory or trim assumptions. That extra check prevents choosing a tire with the right width but the wrong wheel diameter and profile.

Infiniti M37 tires in these sizes are available with Blackwall, RWL, and Redline sidewall styles. Blackwall choices appear in the 245/40R20 fitment from BFGoodrich and Nitto, while Pro-Trac Street Pro III products add RWL and Redline options in both 245/50R18 and 245/40R20. That gives Infiniti M37 owners both conventional modern styling and more custom-oriented sidewall treatments.

Sidewall style affects the visual character of the car more than fitment, so it is usually a secondary decision after size and wheel diameter are settled. Blackwalls maintain a clean late-model luxury-sport appearance, while RWL and Redline options can push Infiniti M37 toward a more personalized or nostalgic custom look. Keep the intended presentation of the car in mind when narrowing the final choice.

Four brands appear in the available Infiniti M37 fitments here: Pro-Trac, BFGoodrich, BFG g-Force, and Nitto. Pro-Trac covers both the 18-inch and 20-inch sizes with Street Pro III offerings, while BFGoodrich and Nitto appear in the 245/40R20 fitment. All listed options are radial tires.

Brand choice matters once the basic fitment is settled, because not every brand covers both wheel diameters or every sidewall presentation. If your Infiniti M37 uses 18-inch wheels, the current options are narrower than they are for the 20-inch package. If appearance, tread personality, or brand preference is part of the decision, sort by size first and then compare the available makers within that fitment.

Infiniti M37 tires here appear in four series: Street Pro III, g-Force Comp 2 AS, Nitto NT555 G2, and g-Force Phenom T/A. Street Pro III is offered in both 18-inch and 20-inch fitments and is also the series that brings RWL and Redline sidewall choices. The other series appear in the 245/40R20 size and expand the range of modern radial performance-oriented options for the 20-inch wheel package.

For most Infiniti M37 owners, the real decision path is wheel diameter first, then series and sidewall style second. The 18-inch setup points you toward the available 245/50R18 choices, while the 20-inch setup opens a wider field of series options. Think of the series name as a way to compare intended driving character and appearance once the correct base size has been confirmed.

An Infiniti M37 that sits for long periods should be stored on a clean, dry surface away from direct sunlight, ozone sources, and large temperature swings. Keep the tires inflated to an appropriate operating pressure for storage and move the car occasionally if possible to reduce flat-spotting. Clean tires and wheels before storage so brake dust and road film do not sit on the rubber for months at a time.

Long periods of inactivity can age tires even when tread wear is minimal, especially on a heavier luxury sport sedan like Infiniti M37. If the car is stored seasonally, inspect the sidewalls and tread blocks before returning it to service. Owners who drive infrequently often see aging and flat-spot concerns before they see conventional wear bars.

Tires on an Infiniti M37 should be inspected regularly, with a quick visual check before driving and a more thorough inspection several times during the year. Look for uneven shoulder wear, cracking, punctures, bulges, and any sign that the tire has been run underinflated. On 20-inch fitments with shorter sidewalls, curb damage deserves especially close attention.

Frequent inspection helps catch alignment, inflation, and suspension issues before they become expensive tire problems. If your Infiniti M37 is driven only occasionally, time-based checks matter just as much as mileage-based checks because low annual use can hide aging rubber. A consistent inspection routine is one of the simplest ways to protect both ride quality and high-speed confidence.

Infiniti M37 tires should be replaced when they show structural damage, significant age-related cracking, impact injury, irregular wear that cannot be corrected, or any other condition that compromises the casing, even if tread depth still looks usable. Tread depth alone is not a complete measure of serviceability. Collector-minded or low-mileage cars often reach the end of safe tire life through age before they wear out through mileage.

That is especially important on a car like Infiniti M37, where highway-capable performance puts real demand on the tire. If there is any doubt about age or condition, have the tires evaluated by a qualified tire professional before regular road use. Replacing an aged tire set early is usually far less costly than dealing with vibration, poor wet grip, or a failure risk later.

Infiniti M37 uses two fitment families in the 2011 to 2013 range covered here: 245/50R18 on 18-inch wheels and 245/40R20 on 20-inch wheels. Both are modern metric radial sizes, which reflects the period and the car's luxury sport sedan role. The model-year range does not narrow that down further because both sizes appear across all three years.

For an originality-focused Infiniti M37, the most reliable approach is to verify the original wheel package carried by the specific car. The door-jamb label, original wheel set, and factory literature are the best references for that kind of confirmation. Once the wheel diameter is established, you can focus on maintaining the proper overall look with the correct profile and preferred sidewall presentation.

Correct tire fitment can affect how an Infiniti M37 is judged by knowledgeable buyers, especially when the car is being presented as unusually original or carefully preserved. The right size maintains the intended proportions of the body and wheel opening, and the correct wheel diameter keeps the car visually and mechanically coherent. Even on newer collector-interest vehicles, incorrect profile or diameter stands out quickly.

For a well-kept Infiniti M37, authenticity usually means matching the original wheel package first and then choosing a tire that suits the owner's presentation goals. A subtle blackwall appearance may read closest to factory luxury-sport character, while RWL or redline options create a more personalized impression. If the car is being judged, consistency with factory configuration is the safer path.

Infiniti M37 tires are available here with Blackwall, RWL, and Redline sidewall styles. Blackwall is the most natural match for a modern luxury sport sedan presentation, while RWL and Redline sidewalls push the car toward a more custom visual statement. All of those styles fit within the available size range, but they do not create the same overall appearance.

If your goal is a factory-like Infiniti M37, blackwall is the most conservative choice. If the car is being built with a period-custom or personalized theme, the Pro-Trac RWL and Redline offerings can shift the look without changing the underlying fitment. The best answer depends on whether you are preserving original character or deliberately adding visual flair.

The listed Infiniti M37 tires are modern radial designs intended for road use when they are properly fitted, correctly inflated, and in sound condition. The available sizes match either the 18-inch or 20-inch wheel packages used on 2011 through 2013 Infiniti M37 models. Safe operation still depends on choosing the correct wheel diameter and maintaining the tires appropriately.

Public-road safety is about more than matching the size code. Check age, condition, inflation, wheel condition, and alignment before expecting normal touring or highway behavior from an Infiniti M37. A correct-size tire on the wrong wheel diameter is unusable, and an aged or damaged tire in the right size is still not ready for road duty.

Before driving an Infiniti M37, check that all four tires are the correct size for the wheel diameter fitted to the car, inspect inflation pressures, and look for visible damage or abnormal wear. Also confirm that the tires are seated properly on the wheels and that there are no cracks, bulges, or punctures. If the car has been sitting, pay extra attention to flat spots and age-related hardening.

Those quick checks matter because Infiniti M37 combines sedan weight, highway capability, and responsive handling, all of which place real demand on the tires. A short pre-drive routine can reveal problems that are not obvious once you are already on the road. If anything feels off through the steering wheel or seat, inspect the tires again before continuing normal use.

An Infiniti M37 should only be driven at speeds appropriate to the exact tire fitted, its condition, and the vehicle's overall mechanical state. The available fitments here are modern radial tires, and some 20-inch options list performance-oriented service descriptions, but safe speed always begins with a healthy tire, correct inflation, and proper wheel fitment. No speed capability should be assumed from size alone.

For a road-going Infiniti M37, the practical rule is to treat the tire as part of the whole system rather than the only deciding factor. If the tires are older, have uneven wear, or the car has been stored, use conservative speeds until the entire setup is inspected. Stable high-speed behavior depends on correct sizing, balance, suspension condition, and tire health working together.