2018 Genesis Tire Fitment Guide

2018 Genesis vehicles use five sizes across two models. The G80 uses 245/45R18, 245/40R19, and 275/35R19, while the G90 uses 245/45R19 and 275/40R19. Rim diameter differs by size, with the G80 spanning both 18-inch and 19-inch applications and the G90 staying with 19-inch fitments. Where rim-width guidance is available, 245/45R18 fits 7.5 to 9.0 inches, 245/40R19 fits 8.0 to 9.5 inches, 275/35R19 fits 9.0 to 11.0 inches, 245/45R19 fits 7.5 to 9.0 inches, and 275/40R19 runs from 9.0 to 11.0 inches, with one BFGoodrich application shown at 9.00 to 9.50 inches.

That means year and make alone are not enough for a confident replacement choice on a 2018 Genesis. You need the model first, then the exact wheel diameter and tire size from the car itself, especially on 19-inch staggered applications where the front and rear sizes differ. Matching the existing size is usually the cleanest path unless you are intentionally changing wheels.

On a 2018 Genesis, 245/45R18 is a metric radial size. The 245 is the nominal section width in millimeters, 45 is the aspect ratio, the R means radial construction, and 18 is the wheel diameter in inches. In this year and make, that size belongs to the G80 and mounts on 18-inch wheels, with published rim-width ranges centered around 7.5 to 9.0 inches.

That decoding helps you separate it from the G80's 19-inch fitments, which use a different sidewall height and wheel diameter. A tire with the same 245-millimeter width but a different aspect ratio or rim diameter is not the same fitment. If your G80 wears 18-inch factory wheels, 245/45R18 is the size family you should confirm against the sidewall before selecting a product.

No, 2018 Genesis models do not share one common tire size. The G80 uses one 18-inch size and two 19-inch sizes, while the G90 uses a different pair of 19-inch sizes. Even though several sizes have the same 245- or 275-millimeter section width, their aspect ratios and model applications are different, so they are not interchangeable by default.

That matters most for owners who know they have a 2018 Genesis but have not yet narrowed the car to G80 or G90. It also matters on cars with staggered 19-inch setups, where a front size and a rear size work together as a set. Checking the sidewall on the car and verifying the model will prevent a mismatch in diameter, width, or intended axle position.

2018 Genesis tires in these sizes are offered as blackwalls across all five fitments. That includes 245/45R18, 245/40R19, 275/35R19, 245/45R19, and 275/40R19 from BFGoodrich and Nitto. No whitewall or period-style collector sidewall treatments appear in these applications, which fits the modern luxury-sport character of the G80 and G90.

For most owners, that keeps the decision focused on size, brand, and tire series rather than sidewall appearance. A blackwall also preserves the contemporary OEM-style look these cars were designed around. If visual presentation matters, the main styling difference will come from tread and sidewall branding details between series rather than from a fundamentally different sidewall treatment.

BFGoodrich and Nitto cover 2018 Genesis fitments in the sizes used by the G80 and G90. BFGoodrich appears across all five sizes, while Nitto is available in 245/45R18, 275/35R19, 245/45R19, and 275/40R19. The 245/40R19 size is represented by BFGoodrich products in this range, while the other sizes include a mix of BFGoodrich and Nitto options.

That gives most 2018 Genesis owners a choice between multiple tire families within the correct size, even when the sidewall style remains the same blackwall format. If you are comparing options, start with the exact size and then look at the series within that size rather than trying to compare across different fitments. Brand choice only matters after the fitment is correct.

For 2018 Genesis sizes where both appear, the g-Force Comp 2 A/S and g-Force Phenom T/A share radial construction and blackwall styling, but they differ in details such as speed rating, weight, and published load information. In 245/45R18, for example, the Comp 2 A/S appears as a 96W at 28 pounds, while the Phenom T/A appears as a 100Y at 25.95 pounds with a 1,764-pound load rating at 50 psi. Similar differences appear in the 19-inch sizes, where the Phenom T/A commonly carries a Y rating and published load figures.

The practical takeaway is to compare the exact size first and then look at the individual series specs inside that size. Two tires can share the same nominal dimensions yet differ in speed category and other published characteristics. If your priorities include matching a particular speed rating or reviewing maximum load information, compare those figures at the product level before making your final selection.

Rim-width guidance varies by size on 2018 Genesis vehicles. 245/45R18 fits 7.5 to 9.0 inches, 245/40R19 fits 8.0 to 9.5 inches, 275/35R19 fits 9.0 to 11.0 inches, 245/45R19 fits 7.5 to 9.0 inches, and 275/40R19 fits 9.0 to 11.0 inches, with one BFGoodrich 275/40R19 application narrowed to 9.00 to 9.50 inches. Those ranges are size-specific and should not be carried from one fitment to another.

That is especially important on 19-inch Genesis applications because the front and rear tires are not always the same width. A wheel that suits a 245-section tire may not be correct for a 275-section tire. Before replacing tires on a G80 or G90, confirm both the tire size and the actual wheel width so the replacement falls inside the published range for that exact size.

The 2018 Genesis sizes covered here are modern radial performance fitments, and no tube-type markings appear in these products. The size markings use contemporary ZR-style radial nomenclature rather than tube-type collector-era coding, and these applications are treated as tubeless passenger-car tires. That aligns with the original design intent of a 2018 luxury sedan using modern one-piece road wheels.

Even so, the wheel condition still matters. A tubeless tire depends on a sound bead seat and a healthy valve stem to hold air properly, so corrosion, curb damage, or bent rims can create problems that look like tire issues. If you are refreshing an older set of wheels on a used Genesis, inspect the wheels and replace valve stems as part of the installation.

A 2018 Genesis should be stored in a cool, dry space away from direct sunlight, electric motors, welders, battery chargers, and other ozone sources that accelerate rubber aging. Keep the tires properly inflated, avoid long-term parking on damp ground, and move the car periodically so one section of tread is not carrying the load for months at a time. Because these are radial tires, they generally tolerate storage better than older bias-ply designs, but they still age from heat, ozone, and inactivity.

For seasonal or collector use, a short drive or careful repositioning every few weeks helps reduce flat spotting and keeps the car from sitting in one footprint. If the Genesis will be parked for an extended stretch, some owners use tire cradles or stands to reduce sustained load on the casing. The goal is preserving the tire's shape and the rubber's condition, not simply protecting tread depth.

On a 2018 Genesis, tire age matters at least as much as mileage. A good rule is to begin evaluating collector or low-use tires closely once they reach the five- to seven-year range and to consider replacement around ten years from the DOT date code even if the tread still looks serviceable. Heat cycles, storage conditions, and time all affect the internal structure long before a low-mileage luxury sedan wears its tread away.

That means a lightly driven G80 or G90 can still need tires simply because the rubber has aged out. Check the four-digit DOT date code on each tire and inspect all sidewalls for weathering, hardening, or cracking. If the car has mixed tire ages, treat the oldest tire as the limiting factor rather than assuming the whole set has the same service life.

Tires on a 2018 Genesis deserve a quick inspection before every drive and a more deliberate inspection before any longer trip. Look for cuts, bulges, uneven wear, punctures, sidewall cracking, and any loss of pressure. Because these cars often use performance-oriented low-profile radials, curb damage and impact damage deserve special attention, especially on 19-inch fitments.

A monthly pressure check is a good baseline even when the car is not being driven regularly, and it is smart to include the spare if the car carries one. Before a highway trip, inspect the inner sidewall as well as the outer face, since hidden damage can be missed during casual washing. Early inspection is one of the simplest ways to protect both ride quality and wheel condition on a luxury sedan.

A 2018 Genesis G80 was originally engineered around modern radial tires, not bias-ply or vintage-style constructions. In this range, the G80 uses 245/45R18 or a 19-inch combination of 245/40R19 and 275/35R19, depending on wheel and package. Those sizes reflect contemporary luxury-sport sedan practice, with low-profile radials matched to larger-diameter wheels for steering response, braking consistency, and the expected appearance of the car.

For authenticity on a modern Genesis, correct size and wheel diameter matter more than period-style sidewall treatment, since the car belongs to a late-model luxury segment rather than a classic concours era. If your goal is an OEM-style presentation, match the existing size exactly and keep the blackwall look the car was designed around. For package-specific confirmation, a Genesis dealer reference or marque specialist remains the best final check.

Correct tire fitment does matter when showing a 2018 Genesis, although the standards are different from prewar or muscle-car judging. On a modern luxury sedan, judges and knowledgeable enthusiasts notice whether the car carries the proper overall size, the correct front-to-rear relationship on staggered setups, and an appropriate blackwall sidewall appearance. A visibly wrong aspect ratio, incorrect wheel diameter, or mismatched front and rear sizing can disrupt the car's factory stance and visual balance.

That means authenticity for a 2018 Genesis is mostly about preserving the intended proportions and equipment style rather than chasing a specific vintage brand image. If the car is being prepared for a marque event or a very detail-oriented display, confirm the exact wheel package the car left the factory with before replacing tires. Staying with the proper size family does more for presentation than chasing cosmetic differences between otherwise correct modern radials.

On 2018 Genesis sizes where both appear, BFGoodrich g-Force Sport Comp 2 and Nitto NT555 G2 share radial construction and blackwall styling, but they are not identical in published details. In 245/45R18, the BFGoodrich appears at 28 pounds with a 1,565-pound maximum load at 51 psi, while the Nitto appears at 27.37 pounds with a 1,764-pound maximum load at 50 psi. In 275/40R19, the BFGoodrich appears at 32 pounds with a 1,819-pound maximum load at 51 psi, while the Nitto appears at 32.84 pounds and uses an XL-marked 105W size designation.

Those differences show why it is worth comparing products within the same size rather than assuming all modern performance radials are interchangeable. Weight, load index, and sidewall construction cues such as XL marking can shape which product best suits your priorities. Once the exact Genesis size is confirmed, compare the product-level specifications that matter most to how the car is driven and maintained.

Yes, the 2018 Genesis tire sizes here are modern radial highway-capable fitments, and the products shown carry W or Y speed ratings depending on the tire. W-rated tires are rated to 112 mph, while Y-rated tires are rated to 186+ mph. Those ceilings are far beyond normal U.S. highway speeds, so the more important real-world issues are correct size, sound condition, proper inflation, and matching the front and rear fitments where the car uses a staggered setup.

On a 2018 Genesis, tire capability is only one part of safe highway use. Suspension wear, alignment, brake condition, and wheel integrity all matter on a heavy luxury sedan, especially if it is being driven after long storage or on aged tires with plenty of tread left. A correctly sized new tire is a strong starting point, but the car itself still needs to be road-ready.

Inflation pressure on a 2018 Genesis should follow the factory vehicle placard or owner's manual for normal service, not a one-size-fits-all number. Some of these tire products also publish maximum load and pressure figures, such as 1,764 pounds at 50 psi for one 245/45R18 option, 1,653 pounds at 50 psi for one 245/40R19 option, 1,874 pounds at 50 psi for one 245/45R19 option, and up to 2,039 pounds at 50 psi for one 275/40R19 option. Those figures describe the tire's rated maximum load at a stated pressure, not necessarily the vehicle's everyday operating pressure.

The safest approach is to use the Genesis-recommended cold pressure for your exact model and wheel package, then confirm the chosen tire is appropriate for that service. Do not transfer a pressure figure from one size to another just because the car is the same year and make. If the car has aftermarket wheels or a nonstandard setup, verify both the wheel and tire manufacturer guidance before setting pressures.

Before taking a 2018 Genesis on a longer drive, inspect each tire for cracking, punctures, bulges, and uneven wear, then verify cold inflation pressure on all four corners. Confirm that the front and rear sizes are correct for the car, especially on 19-inch staggered applications, and check the spare if the vehicle carries one. It is also wise to look for curb damage or bent wheels, since low-profile luxury-sedan tires can mask wheel issues until the car is at speed.

A longer trip is also the right time to broaden the check beyond the tires alone. Make sure the brakes, alignment, battery, and fluid levels are all in good order, particularly if the Genesis has been sitting or is driven only occasionally. Tires are the only part touching the road, but they perform best when the rest of the chassis and running gear are equally ready for sustained highway use.