The 2018 Lexus IS300 sits in the modern sport sedan category where balanced handling, sharp response, and a clean factory stance matter as much as everyday drivability. On this model, tire fitment depends on the exact wheel setup, with a 225/45R17 fitment on 17-inch wheels and a staggered 18-inch arrangement using 225/40R18 front and 255/35R18 rear. That makes the key decision less about vintage construction choices and more about confirming whether the car has the standard or staggered setup. Available options also vary by brand, tire series, and sidewall treatment, so the right selection should match both the car's wheel package and the way it is actually driven.
Which Tire Size Is Right for The 2018 Lexus IS300
Three primary tire sizes apply to the 2018 Lexus IS300, and the correct choice depends first on whether the car is running 17-inch wheels or the staggered 18-inch front-and-rear setup. Both AWD and RWD versions can use either arrangement, so identifying the exact wheel and axle position is more important than choosing by drivetrain alone.
225/45R17 is a metric radial size in which 225 refers to section width in millimeters, 45 is the aspect ratio, R indicates radial construction, and 17 is the rim diameter in inches. On the 2018 Lexus IS300, this size is used on 17-inch wheel setups rather than the staggered 18-inch package. Available choices include BFGoodrich, Nitto, and Pro-Trac options, with Blackwall, raised white letter, and Redline sidewall treatments depending on the tire series. This size is the one to evaluate when the car retains its 17-inch wheels and a square fitment on all four corners.
Fit(s): (AWD) Front, (RWD) Front, and F Sport Front
Construction: Radial|Rim: 18 in
225/40R18 is a metric radial size with a 225-millimeter section width, a 40-series profile, radial construction, and an 18-inch rim diameter. On the 2018 Lexus IS300, this size serves as the front tire in the staggered 18-inch setup used on AWD, RWD, and F Sport front applications. Product choices center on Blackwall performance-oriented tires from BFGoodrich and Nitto across several g-Force and NT555 G2 series offerings. This is the correct size to review when confirming the front axle fitment on an IS300 equipped with the larger staggered wheel package.
255/35R18 is a wider metric radial size in which 255 gives the section width in millimeters, 35 is the aspect ratio, R marks radial construction, and 18 identifies the wheel diameter. For the 2018 Lexus IS300, this size is used at the rear on staggered 18-inch applications, pairing with 225/40R18 in front. Available selections include BFGoodrich and Nitto products in Blackwall form, with differences in tire series, rim-width compatibility, load figures, and overall product character. This rear size matters most when preserving the intended staggered setup rather than converting the car to a same-size arrangement.
Sub-model fitment on the 2018 Lexus IS300 is driven more by wheel package and axle position than by name alone. Some versions use 225/45R17 at all four corners, while others use a staggered 18-inch setup with different front and rear sizes.
1
2018 Lexus IS300 (AWD)
The 2018 Lexus IS300 (AWD) uses the 225/45R17 radial size when equipped with the 17-inch setup. Tire selection here focuses on choosing among available brands and sidewall treatments while confirming that the car has not been changed to the staggered 18-inch arrangement.
The 2018 Lexus IS300 (AWD) Front uses 225/40R18 as part of the staggered 18-inch package. Front tire selection should stay focused on that axle position and be matched carefully to the corresponding 255/35R18 rear fitment.
The 2018 Lexus IS300 (AWD) Rear uses the wider 255/35R18 radial size in the staggered 18-inch setup. Rear tire choice should account for the car's axle-specific fitment and be kept consistent with the 225/40R18 front size already on the vehicle.
The 2018 Lexus IS300 (RWD) also uses 225/45R17 when equipped with the 17-inch square setup. That makes wheel confirmation important, since some RWD cars are instead configured with separate 18-inch front and rear sizes.
The 2018 Lexus IS300 (RWD) Front uses 225/40R18 on staggered 18-inch applications. Choosing the right tire means matching the front axle size correctly and avoiding the assumption that the rear uses the same dimensions.
The 2018 Lexus IS300 (RWD) Rear uses 255/35R18 with the staggered 18-inch wheel package. Rear fitment should be checked separately from the front so the car keeps the intended width and profile balance across both axles.
The 2018 Lexus IS300 F Sport Front uses 225/40R18 radial tires. That front fitment should be chosen with the rear axle size in mind, especially when replacing only two tires on a staggered-wheel car.
The 2018 Lexus IS300 F Sport Rear uses 255/35R18 radial tires. Tire selection at the rear should preserve the staggered relationship with the 225/40R18 front size and confirm wheel width before changing series or brand.
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 2018 Lexus IS300 Tires for Sale
Available 2018 Lexus IS300 tires vary by size, brand, series, and sidewall presentation. BFGoodrich and Nitto cover the main Blackwall performance selections, while 225/45R17 also includes Pro-Trac Street Pro III options with raised white letter and Redline sidewall treatments.
These FAQs focus on the exact tire sizes used on the 2018 Lexus IS300, including 17-inch versus staggered 18-inch fitment, axle-specific sizing, product selection, and the wheel and condition checks worth making before road use.
Tire Size & Fitment
What tire size fits a 2018 Lexus IS300?
The 2018 Lexus IS300 uses three primary tire sizes depending on wheel setup: 225/45R17, 225/40R18, and 255/35R18. The 225/45R17 size is used on 17-inch square setups, while the 18-inch arrangement is staggered, with 225/40R18 in front and 255/35R18 in the rear.
The practical first step is confirming what is actually on the car now. An IS300 with 17-inch wheels should not be treated the same as one with staggered 18-inch wheels, and front and rear sizes must be checked separately before replacing tires or comparing product options.
What size rim does a 2018 Lexus IS300 use?
A 2018 Lexus IS300 uses either 17-inch or 18-inch rims, depending on the tire size and wheel package. The 225/45R17 size mounts on a 17-inch rim, while 225/40R18 and 255/35R18 both use 18-inch rims in the staggered setup.
Rim diameter should be verified before anything else, since a tire for a 17-inch wheel cannot be mounted on an 18-inch wheel. Once diameter is confirmed, it is also smart to check wheel width, especially on staggered cars where the rear wheel and tire package differs from the front.
Why does the 2018 Lexus IS300 have more than one tire size?
The 2018 Lexus IS300 has more than one tire size because it was offered with different wheel configurations. Some versions use a square 17-inch setup with 225/45R17 at all four corners, while others use a staggered 18-inch layout with 225/40R18 front and 255/35R18 rear.
That means tire selection is tied to the actual wheel package rather than the model name alone. Looking at the sidewall markings already on the car and checking whether the front and rear tires match is the fastest way to avoid ordering the wrong size.
Choosing the Right Tire
What should I consider when choosing a 2018 Lexus IS300 tire?
Start with the exact size and wheel setup on the car, since the 2018 Lexus IS300 may use 225/45R17 on all four corners or a staggered 18-inch combination with 225/40R18 front and 255/35R18 rear. Every applicable option here is a radial tire, so the main variables become size, wheel compatibility, and product character.
After size is confirmed, compare tire series, sidewall style, rim-width recommendations, weight, and any stated load figures that matter to your use. That approach keeps the focus on a tire that suits the car's actual wheel package instead of choosing only by appearance or brand name.
What sidewall styles are available for 2018 Lexus IS300 tires?
Sidewall style depends on tire size. Blackwall options are available across all three primary sizes, while 225/45R17 also includes raised white letter and Redline choices through the Pro-Trac Street Pro III line.
That makes the 17-inch fitment the best place to look if appearance matters as much as basic replacement sizing. On an 18-inch staggered setup, the emphasis stays on Blackwall performance-style tires, so the visual presentation is more restrained and closer to a modern sport sedan look.
What brands offer tires for the 2018 Lexus IS300?
BFGoodrich and Nitto are the primary brands available across the 2018 Lexus IS300 fitments shown here, and Pro-Trac is also available in 225/45R17. BFGoodrich selections include multiple g-Force series and the g-Force Phenom T/A, while Nitto appears in the NT555 G2 line.
Brand choice should come after confirming the correct size and wheel layout. Once that is settled, compare how each offering differs in sidewall treatment, rim-width specification, weight, and the overall style of tire you want on the car rather than assuming every option serves the same purpose.
Restoration & Appearance
Which tire should I choose for a period-style 2018 Lexus IS300?
A period-style approach on a 2018 Lexus IS300 usually means keeping the car's original wheel diameter and overall stance rather than moving to a completely different fitment. That points to 225/45R17 on 17-inch cars or the proper 225/40R18 front and 255/35R18 rear combination on staggered 18-inch cars.
Appearance then comes down to how subtle or expressive the finished look should be. Blackwall tires keep a clean modern presentation, while 225/45R17 offers raised white letter and Redline alternatives for a more customized look without changing the vehicle's primary size category.
How does tire construction affect the appearance of a restored 2018 Lexus IS300?
On the 2018 Lexus IS300, construction does not create a bias-ply versus radial decision because the fitments here are radial tires. Visually, the bigger appearance differences come from wheel size, whether the car uses a square or staggered setup, and the available sidewall treatment in the chosen size.
Keeping the proper front-to-rear relationship matters on 18-inch cars because the staggered look is part of the vehicle's stance. A careful appearance-focused selection should preserve the correct size layout first, then use Blackwall, raised white letter, or Redline details only where those options are actually offered.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Lexus IS300?
Yes, modifications can change tire fitment on a 2018 Lexus IS300 even when the sidewall size looks close to stock. Aftermarket wheels, different wheel widths, offset changes, lowering springs, suspension alterations, or brake upgrades can all affect how 225/45R17, 225/40R18, or 255/35R18 sit on the car.
A modified IS300 should be checked for inner clearance, fender clearance, and proper front-to-rear sizing before replacement tires are chosen. That matters most on staggered 18-inch setups, where the front and rear tires already serve different positions and should not be treated as interchangeable.
What should I inspect before driving a 2018 Lexus IS300 on new tires?
Before driving a 2018 Lexus IS300 on new tires, inspect wheel condition, confirm the correct size at each axle, and make sure inflation is set appropriately for the installed tires. It is also wise to look for uneven wear patterns, alignment issues, and any signs that the old tires were rubbing or wearing irregularly.
A short road test should be used to confirm smooth steering response, stable tracking, and no contact with suspension or bodywork. On cars with staggered 18-inch fitment, double-check that 225/40R18 remains in front and 255/35R18 remains in the rear after installation and rotation service.
How often should tires on a 2018 Lexus IS300 be inspected?
Tires on a 2018 Lexus IS300 should be inspected regularly for tread wear, air loss, cuts, punctures, bulges, and sidewall damage. A car driven spiritedly or on rough roads deserves more frequent checks, especially when it uses lower-profile 18-inch tires with separate front and rear sizes.
Routine inspections are also useful for spotting alignment or suspension issues before they shorten tire life. Looking over the tires during pressure checks and before longer drives helps catch problems early, and that is especially important if the car has aftermarket wheels or has been sitting for extended periods.
