Acura RLX Tires

Acura RLX uses two tire sizes across the 2014 to 2020 production range: 245/40R19 and 245/45R18. The 245/40R19 size appears from 2014 through 2020 and fits 19-inch wheels, while 245/45R18 appears only for 2014 and 2015 models equipped with 18-inch wheels. Both are radial metric sizes, but they are not interchangeable because the wheel diameter is different.

The practical step is to match the tire to the wheel that is actually on the car, not just the model year. Early Acura RLX cars are the ones most likely to create confusion, since 2014 and 2015 can use either size. Checking the sidewall of the existing tire and measuring the wheel diameter will usually settle the question quickly before you compare tread pattern, brand, or performance category.

On an Acura RLX, 245/40R19 breaks down into four pieces of information. The 245 is the tire’s section width in millimeters, the 40 is the aspect ratio, meaning the sidewall height is 40 percent of the section width, the R identifies radial construction, and the 19 is the wheel diameter in inches. That makes it a low-profile radial designed for a 19-inch wheel.

Understanding that code matters because a similar-looking size can still be wrong if the aspect ratio or wheel diameter changes. Acura RLX also appears with 245/45R18 on some early cars, and the two sizes differ in both sidewall height and wheel fit. If you want to preserve the intended stance and handling balance, stay with the exact size that matches the wheel package on your specific Acura RLX.

A 2014 or 2015 Acura RLX can have two tire sizes listed because those years were offered with different wheel packages. One setup uses 245/45R18 on 18-inch wheels, and the other uses 245/40R19 on 19-inch wheels. That is a rim-diameter split, not two alternate tire sizes for the same wheel.

The best way to sort that out is to identify the wheel diameter first and then match the corresponding tire size. Looking only at the year can lead to the wrong choice, since both sizes fall within the same early production window. Once the wheel diameter is confirmed, the correct Acura RLX tire size becomes straightforward and you can compare the available products in that exact fitment.

Acura RLX uses either an 18-inch or 19-inch rim diameter within this production range. The 18-inch wheel pairs with 245/45R18 and appears in 2014 and 2015, while the 19-inch wheel pairs with 245/40R19 and appears from 2014 through 2020. Later Acura RLX fitment in this group is exclusively 19-inch.

That wheel-diameter split is the most important fitment checkpoint on this page. If the car is a 2016 through 2020 Acura RLX, the answer is simple because only the 19-inch size is listed. For 2014 and 2015 cars, verify the wheel itself before doing anything else, since no tire can safely substitute for the wrong wheel diameter even if the width number looks similar.

The correct way to confirm tire size on a 2014 or 2015 Acura RLX is to identify the wheel diameter first. Those years use either 245/45R18 on 18-inch wheels or 245/40R19 on 19-inch wheels, so the model year alone is not enough. The existing tire sidewall, the wheel diameter, and the door-jamb tire information label should all point to the same size.

Once the wheel diameter is confirmed, compare the replacement tire’s size and approved rim-width range to the wheel on the car. The 18-inch option is listed for 7.5 to 9.0 inch wheel widths, while the 19-inch option is listed for 8.0 to 9.5 inch widths. That extra check helps avoid a mismatch that might mount physically but alter the intended handling and appearance of the Acura RLX.

The available Acura RLX tires in these sizes are all listed with blackwall sidewalls. That applies to both 245/40R19 and 245/45R18 products across the brands represented here. There is no whitewall or specialty sidewall variation in this fitment group.

Blackwall is the natural visual match for a modern Acura RLX and preserves the car’s contemporary luxury-sport appearance. If you are trying to keep the car close to its factory-era presentation, staying with blackwall is the straightforward choice. From there, your decision comes down to size confirmation, brand preference, and the kind of driving character you want from the tread design.

The Acura RLX tire options listed here come from BFGoodrich and Nitto. BFGoodrich appears in both 18-inch and 19-inch fitments, while Nitto appears in the 245/45R18 size. All of the products in this Acura RLX group are radial tires with blackwall styling.

Brand choice becomes a secondary decision after the size is settled, especially for 2014 and 2015 cars that may use either wheel diameter. Once you know whether your Acura RLX takes the 18-inch or 19-inch fitment, you can compare the available product lines within that exact size. That keeps the process focused on proper fit first and performance character second.

Acura RLX tires in this group appear in four series: g-Force Sport Comp 2, g-Force Comp 2 AS, g-Force Phenom T/A, and Nitto NT555 G2. All four are radial constructions, so the difference is not bias-ply versus radial but one product line versus another within modern performance-oriented tire families. The available series also vary by wheel size, with some options appearing in both fitments and some only in the 18-inch size.

That means the right comparison starts with the wheel diameter on the car and then narrows to the product family available in that size. An owner keeping an Acura RLX primarily for fair-weather driving may lean toward a different tread style than one using the car more broadly. Even so, keeping the exact listed size and matching the approved wheel-width range should stay ahead of tread preference in the decision process.

An Acura RLX stored on its tires should be kept in a cool, dry, dark space away from direct sunlight, electric motors, welders, and ozone sources. Clean the tires first, set inflation to the vehicle maker’s recommended pressure, and avoid long-term parking on damp earth or bare concrete if possible. Moving the car slightly from time to time can also help reduce flat spotting during extended storage.

That matters most on a low-use luxury sedan because the tread may look excellent long after age-related hardening begins. If the Acura RLX will sit for months at a time, periodic inspection of sidewalls and tread shoulders is wise before returning it to regular use. Proper storage preserves ride quality and helps the car feel as composed on the road as a flagship sedan should.

Tires on an Acura RLX should be inspected at least monthly and again before any longer trip or extended highway drive. Check inflation pressure, tread wear pattern, sidewall condition, and any signs of impact damage, punctures, or cracking. Because Acura RLX uses low-profile fitments in this range, curb damage and pothole impacts deserve especially close attention.

A regular inspection routine helps catch problems before they affect ride quality, handling, or wet-road confidence. Uneven wear can also point to alignment or suspension issues that become more noticeable on 18-inch and 19-inch performance-oriented tire sizes. If an Acura RLX has been sitting for part of the season, inspect the tires before assuming they are ready for normal road use.

Tires on an Acura RLX should be replaced when they show cracking, impact damage, persistent vibration, irregular wear, or age-related hardening even if the tread depth still looks serviceable. Collector and low-mileage cars often age out their tires before they wear them out. A tire can appear presentable yet no longer deliver the grip, flexibility, and stability expected on a modern luxury sedan.

The key is to treat condition and age as seriously as tread depth, especially if the Acura RLX sees occasional use rather than daily driving. If ride quality suddenly feels harsher or the car follows road grooves more than it used to, the tires deserve close evaluation. Replacing aging tires before visible failure helps preserve both the car’s refinement and its road manners.

The listed Acura RLX tires are modern radial road tires, so they are intended for normal public-road use when they are the correct size for the wheel and are in sound condition. The crucial safety point is fitment accuracy: 245/45R18 belongs on 18-inch wheels and 245/40R19 belongs on 19-inch wheels. A tire in the wrong diameter is not a usable substitute.

Safe road use also depends on the usual fundamentals of tire care, including inflation, condition, alignment, and absence of damage. On early Acura RLX models, the risk is choosing by year alone and overlooking the wheel package actually fitted to the car. Once size and wheel diameter are matched correctly, the focus shifts to maintaining the tires so the sedan’s handling and braking remain predictable.

Before driving an Acura RLX, check tire pressure, visible tread and sidewall condition, and confirm there is no puncture damage or bulging from impacts. It is also wise to look for uneven wear that could suggest alignment or suspension issues. On 2014 and 2015 Acura RLX models, confirming that the tire size matches the wheel diameter is especially important if the car recently changed hands.

That short pre-drive routine is worthwhile because modern low-profile tires can be sensitive to underinflation and road-impact damage. If the Acura RLX has been stored, rolled infrequently, or driven only seasonally, give the tires a more deliberate inspection before resuming normal speeds. A few minutes in the garage can prevent a poor-driving experience and help preserve the composed character the RLX is known for.

An Acura RLX on the correct original-size replacement tires should be driven at prudent legal road speeds consistent with the tire’s service condition, inflation, and the car’s mechanical state. The products listed here include W- and Y-rated fitments in these sizes, but real-world speed choice should always be governed by road conditions and the condition of the individual tire. Correct size alone does not override age, wear, or damage concerns.

For a low-mileage or intermittently used Acura RLX, conservative use until the tires have been fully inspected is the sensible approach. If the car has older tires, recent curb strikes, or any vibration, resolve those issues before sustained highway driving. The goal is to let the car operate within the safe margin its tire condition actually supports, not simply what the sidewall rating suggests in isolation.