2015 Acura RLX Tires

The 2015 Acura RLX uses two primary tire sizes: 245/40R19 and 245/45R18. Both are radial fitments, and both are tied to different wheel diameters rather than different tire constructions. Because the sizes are close in overall diameter but use different rims, the correct choice depends on the wheel package actually installed on the car.

The practical step is to confirm whether the RLX has 18-inch or 19-inch wheels before choosing a tire. The sidewall marking on the current tire and the wheel itself usually make that clear. Once the rim diameter is confirmed, compare tires only within that matching size so wheel fitment, sidewall profile, and handling character stay aligned with the setup already on the car.

A 2015 Acura RLX uses either an 18-inch or 19-inch rim, depending on which tire size is on the car. The 245/45R18 size pairs with an 18-inch rim, while the 245/40R19 size pairs with a 19-inch rim. Both are radial tire applications, but they are not the same wheel-and-tire package.

Rim diameter should be verified before anything else because an 18-inch tire cannot be mounted on a 19-inch wheel, and vice versa. Tire selection should also take wheel width into account, since the available products carry specific rim-width ranges. Looking at the current wheel size first keeps the search focused on tires that match the car’s existing setup rather than just the model name.

The 2015 Acura RLX Base is associated with both 245/40R19 and 245/45R18, so there is not one single tire size tied exclusively to that sub-model. Both sizes are radial fitments, and the deciding factor is the wheel diameter on the individual car. In practice, the Base model can appear with either wheel-and-tire combination.

That means trim name alone is not enough to select tires for an RLX Base. Check the sidewall size on the current tires, verify the wheel diameter, and then compare tires only within that matching size. This is especially important if the car has had wheel changes at some point, since the installed setup matters more than the sub-model label when ordering replacement tires.

Start with the correct size for the wheel on the car: 245/40R19 for 19-inch wheels or 245/45R18 for 18-inch wheels. From there, compare radial tire series, rim-width compatibility, load figures where stated, and the type of driving the RLX sees most often. Since this is a full-size luxury sedan, the tire choice strongly influences ride feel and steering response.

A useful way to narrow the options is to decide whether the priority is everyday all-season versatility or a more performance-oriented road feel. The available products include several BFGoodrich g-Force series options and, in 245/45R18, a Nitto NT555 G2 choice. Matching the tire to the car’s actual wheel size and intended use matters more than choosing by brand name alone.

The available tires for the 2015 Acura RLX use blackwall sidewalls in both primary sizes. That applies across the 245/40R19 and 245/45R18 product choices shown for this vehicle. There are no alternate whitewall, redline, or raised white letter options in the listed RLX tire selection.

For most RLX owners, that keeps the decision focused on tire series and fitment details rather than appearance-driven sidewall styling. Blackwall presentation suits the car’s modern luxury-sport character and keeps the look clean and understated. The more meaningful comparisons are construction details within each series, acceptable rim-width range, and whether the tire’s character matches how the sedan is driven.

BFGoodrich and Nitto both offer tires for the 2015 Acura RLX within the sizes shown here. BFGoodrich appears in both 245/40R19 and 245/45R18 through several g-Force series options, while Nitto appears in the 245/45R18 size with the NT555 G2. All of these are radial blackwall tires.

Brand choice should be considered alongside the specific size and series rather than as a stand-alone decision. BFGoodrich offers the broadest spread across the RLX fitments here, while Nitto adds another 18-inch option for owners running 245/45R18. Once the correct wheel diameter is confirmed, compare each tire’s rim-width range, load specification when stated, and overall driving purpose.

A period-style approach on a 2015 Acura RLX generally means staying with the correct modern radial size for the wheel package already on the car. That points to either 245/40R19 or 245/45R18, both in blackwall form. Since the RLX is a modern flagship sedan rather than a vintage restoration project, the visual goal is usually maintaining the car’s original-era proportions and clean presentation.

The best way to preserve that look is to avoid changing rim diameter unless there is a deliberate reason to do so. Tire series can still change the character of the car, but the correct size keeps the stance and sidewall profile in the right neighborhood. For owners pursuing exact original-era presentation, vehicle-specific documentation and Acura reference material remain the strongest guide.

Correct tire fitment matters on a 2015 Acura RLX because the car’s appearance and driving balance depend on matching the proper wheel diameter and tire profile. Using 245/40R19 on a 19-inch wheel or 245/45R18 on an 18-inch wheel keeps the tire proportion aligned with the RLX’s intended full-size luxury-sedan presentation. Even on a newer collector-minded vehicle, fitment accuracy affects both look and function.

An RLX being preserved in original-style condition benefits from avoiding casual substitutions that alter sidewall height or require different wheel dimensions. Small visual changes can also bring unwanted clearance or ride differences. Checking the installed wheels, confirming the size on the current tires, and keeping the replacement within the proper fitment path is the most dependable way to maintain a coherent restoration-oriented result.

Yes, modifications can affect tire fitment on a 2015 Acura RLX even when the tire size sounds close to stock. Aftermarket wheels may change width or offset, and suspension changes can alter fender, steering, or inner-clearance relationships. That matters with both 245/40R19 and 245/45R18 because each size is tied to a specific rim diameter and an expected wheel fitment window.

A modified RLX should be checked as it sits rather than assumed to match standard replacement practice. Measure the installed wheel diameter, confirm width, and inspect clearance at full steering lock and normal ride height before changing tires. Looking at the tire maker’s rim-width range is also helpful, since a wheel that falls outside that range can create fitment and handling issues even if the size code seems correct.

Before driving a 2015 Acura RLX on new tires, confirm that the tire size matches the wheel diameter, the beads are seated properly, and inflation pressure is set appropriately for the installed tire and vehicle use. It is also worth checking wheel condition, valve stems, and basic alignment-related wear patterns if the old tires came off unevenly.

A short initial inspection after installation helps catch preventable issues early. Look for any rubbing at the inner liner or fender area, especially if the car has non-stock wheels, and make sure the steering turns freely lock to lock. Rechecking pressure after the first few drives, along with watching for vibration or pull, gives a better picture of whether the new setup is settling in as it should.

Tires on a 2015 Acura RLX should be inspected regularly, not only when tread looks worn. A routine visual check for cracking, bulges, cuts, punctures, or uneven wear is important on any modern performance-oriented radial tire, whether the car uses 245/40R19 or 245/45R18. Pressure should also be checked consistently, since underinflation and slow air loss can change how the RLX drives.

Cars that are driven less often still need attention because age and storage conditions matter as much as mileage. Periodic checks are especially useful before highway trips or seasonal use changes. Looking at tire condition, air pressure, and wear pattern together gives a clearer sense of the car’s overall health, and any sign of abnormal wear should prompt a closer look at alignment, suspension, or wheel condition.