The 2013 Infiniti M37 sits in the final years of Infiniti’s M-series sport-luxury sedan era, blending rear-drive performance character with a refined executive-car feel. It is a car that rewards the right tire choice because wheel and trim differences meaningfully shape both stance and fitment. For this exact model, the primary fitment is fully radial, with 245/50R18 used on some sub-models and 245/40R20 used on others. That also opens up different visual directions, from blackwall performance-oriented tires to RWL and redline treatments in selected sizes. The key is matching the tire to the exact sub-model and wheel diameter before comparing style, series, and road-use priorities.
Which Tire Size Is Right for The 2013 Infiniti M37
The 2013 Infiniti M37 uses two primary tire sizes, and the correct one depends on the exact sub-model and wheel diameter. Both fitments are radial, but one uses an 18-inch rim and the other uses a 20-inch rim, so the first step is confirming which wheels are actually on the car before comparing tire style, series, or sidewall treatment.
In 245/50R18, the 245 is the nominal section width in millimeters, the 50 is the aspect ratio, the R identifies radial construction, and the 18 is the rim diameter in inches. This is a modern radial size used on 18-inch-wheel versions of the 2013 Infiniti M37, giving the buyer a straightforward OE-era sizing format to work from. Available choices in this size include Pro-Trac Street Pro III tires with either RWL or redline sidewall styling. It is the right size to evaluate when the car retains its 18-inch wheel setup and the goal is balancing proper fitment with a more customized visual presentation.
In 245/40R20, the 245 is the nominal section width in millimeters, the 40 is the aspect ratio, the R denotes radial construction, and the 20 is the rim diameter in inches. This modern radial size belongs to the 20-inch-wheel M37 configurations and carries a lower-profile look than the 18-inch fitment while staying in the same general width range. Product choices include blackwall performance-oriented options from BFGoodrich and Nitto, along with Pro-Trac Street Pro III tires in RWL and redline versions. It is the size to focus on when the car is equipped with 20-inch wheels and appearance, series differences, and rim-width compatibility matter in the final decision.
Tire fitment for the 2013 Infiniti M37 is not the same across every sub-model. The correct choice starts with identifying whether the car is a Base or X model on 18-inch wheels, or a Sport or X Sport model on 20-inch wheels.
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2013 Infiniti M37 Base
The 2013 Infiniti M37 Base uses the 245/50R18 radial fitment on an 18-inch wheel. That makes the tire decision less about changing size and more about choosing the right radial style and sidewall presentation for the car’s intended look and use.
The 2013 Infiniti M37 Sport uses the 245/40R20 radial fitment on a 20-inch wheel. Tire selection here centers on confirming the 20-inch setup, then comparing blackwall performance-oriented choices against RWL or redline options for a different visual character.
The 2013 Infiniti M37 X uses the same 245/50R18 radial size as the Base model. For this sub-model, the main decision is choosing among the available 18-inch radial options while keeping wheel diameter and overall appearance aligned with the car’s current setup.
The 2013 Infiniti M37 X Sport uses the 245/40R20 radial fitment on a 20-inch wheel, matching the Sport model’s size direction. That means the buyer should confirm the wheel package first, then compare available series, sidewall styling, and rim-width compatibility where relevant.
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 2013 Infiniti M37 Tires for Sale
Available 2013 Infiniti M37 tires vary by size, brand, tire series, and sidewall treatment. Buyers comparing 20-inch fitments will see BFGoodrich, Nitto, and Pro-Trac options, while 18-inch choices center on Pro-Trac Street Pro III with either RWL or redline styling.
These FAQs focus on the exact 2013 Infiniti M37 tire questions that matter most: which size fits each sub-model, how 18-inch and 20-inch setups differ, and how to compare radial choices by style, wheel fitment, and road-use needs.
Tire Size & Fitment
What tire size fits a 2013 Infiniti M37?
The 2013 Infiniti M37 uses two primary tire sizes: 245/50R18 and 245/40R20. The 245/50R18 size applies to the Base and X sub-models, while the 245/40R20 size applies to the Sport and X Sport sub-models, and both are radial fitments.
The practical difference is not just the tire itself, but the wheel diameter that goes with it. Choosing correctly starts with confirming the exact sub-model and checking whether the car still has its intended 18-inch or 20-inch wheels, especially if it has ever been modified or had wheel changes during ownership.
What size rim does a 2013 Infiniti M37 use?
A 2013 Infiniti M37 uses either an 18-inch or 20-inch rim depending on the sub-model. The 245/50R18 fitment is paired with an 18-inch rim, and the 245/40R20 fitment is paired with a 20-inch rim.
Rim diameter is the first fitment point to verify because a tire must match the wheel diameter exactly. Once that is confirmed, the next checks are wheel width, overall tire size, and clearance around suspension and bodywork, particularly on any car that may no longer be on its original wheel package.
Do all 2013 Infiniti M37 sub-models use the same tire size?
No, the 2013 Infiniti M37 does not use one tire size across every sub-model. Base and X models use 245/50R18, while Sport and X Sport models use 245/40R20, so fitment changes with the specific version of the car.
That distinction matters because the two sizes also use different rim diameters and create different tire profiles. Buyers should identify the exact sub-model first, then confirm the actual wheel setup on the car, since previous owners sometimes change wheels and that can separate the current fitment from the original sub-model pattern.
Choosing the Right Tire
What should I consider when choosing a tire for a 2013 Infiniti M37?
Start with the correct size for the exact sub-model: 245/50R18 for Base and X, or 245/40R20 for Sport and X Sport. From there, compare radial construction details, sidewall styling, tire series, and any wheel-fit specifications that apply to the size you are shopping.
The best choice depends on how the car is used and how you want it to look. Some M37 owners may prefer a clean blackwall performance presentation, while others may want RWL or redline styling, so it helps to weigh appearance, wheel compatibility, and the car’s current setup before narrowing the options.
What sidewall styles are available for 2013 Infiniti M37 tires?
Sidewall styles available for the 2013 Infiniti M37 include Blackwall, RWL, and Redline, depending on the tire size and product selected. The 20-inch fitment offers all three styles, while the 18-inch fitment is available in RWL and Redline through Pro-Trac Street Pro III.
That gives the M37 owner a genuine appearance choice rather than just a size decision. Blackwall keeps a more understated modern look, while RWL and redline can add a more custom or enthusiast-oriented visual cue, so the right pick often comes down to how closely the tire should match the car’s wheel and overall styling theme.
What brands offer tires for the 2013 Infiniti M37?
Tires for the 2013 Infiniti M37 are available from Pro-Trac, BFGoodrich, and Nitto. Brand availability depends on the size, with Pro-Trac appearing in both primary fitments and BFGoodrich and Nitto offered in the 245/40R20 size.
Brand is only one part of the comparison. It also helps to look at the tire series, sidewall treatment, and any wheel-fit details attached to the specific size, since two tires in the same nominal size can still suit very different buying priorities in appearance, intended use, and wheel compatibility.
Restoration & Appearance
Which tire should I choose for a period-style 2013 Infiniti M37?
A period-style approach for a 2013 Infiniti M37 begins with staying in the correct primary size for the exact sub-model, then choosing a radial tire whose visual presentation matches the car. On this model, that usually means deciding between a more restrained blackwall look and more expressive RWL or redline styling.
Because this is a modern sport-luxury sedan rather than an earlier collector-era car, appearance usually comes down to preserving the intended character of the wheel package. Matching the tire to the correct 18-inch or 20-inch setup keeps the proportions right, while sidewall style lets the owner lean more factory-inspired or more custom.
How does tire construction affect the appearance of a restored 2013 Infiniti M37?
Tire construction is straightforward on the 2013 Infiniti M37 because the primary fitments are radial. The visible appearance difference comes less from construction type and more from profile, wheel diameter, and sidewall treatment, especially when comparing 18-inch and 20-inch sub-model setups.
A lower-profile 245/40R20 creates a distinctly different visual impression from a 245/50R18, even though both are correct within the M37 range. Owners aiming for a restoration-oriented result should first preserve the proper size for the sub-model, then use blackwall, RWL, or redline styling to fine-tune the finished look.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2013 Infiniti M37?
Yes, modifications can affect tire fitment on a 2013 Infiniti M37 even when the tire size looks close to the original specification. Aftermarket wheels, changes in wheel width, altered offset, suspension lowering, or body modifications can all change how a 245/50R18 or 245/40R20 tire sits in the car.
That is why the current setup matters as much as the original sub-model fitment. A buyer should confirm actual wheel diameter first, then check wheel width, tire clearance at steering lock, and space around the fenders and suspension before assuming the factory size pattern still applies without adjustment.
What should I inspect before driving a 2013 Infiniti M37 on new tires?
Before driving a 2013 Infiniti M37 on new tires, inspect the wheels for damage, confirm the tire size matches the car’s actual wheel diameter, and look over the suspension and alignment condition. It is also smart to verify proper inflation and make sure there is no interference at full steering lock.
Road use will be more predictable when the basics are handled before the first drive. A quick check for uneven previous tire wear, loose components, and any signs of rubbing helps catch problems early, especially on cars that may have non-original wheels or have spent time sitting before returning to regular use.
How often should tires on a 2013 Infiniti M37 be inspected?
Tires on a 2013 Infiniti M37 should be inspected regularly, not just when tread appears low. Frequent checks for pressure loss, abnormal wear, cuts, bulges, and sidewall damage are worthwhile, particularly because this model can run either an 18-inch or 20-inch setup with different profile characteristics.
Inspection matters even more when the car is driven less often or stored for long periods. Looking over the tires before longer trips and after seasonal storage helps catch age-related issues early, and it is a good time to confirm that the wheel and tire package still has proper clearance and even wear across the tread.
