The 2021 Lexus IS300 sits in the modern sport-sedan category, blending Lexus refinement with a chassis that still rewards drivers who care about steering feel, balance, and everyday road manners. For owners, tire choice has a direct effect on how that character comes through on the street. This IS300 uses a 235/45R18 radial tire on an 18-inch rim, and that same primary fitment carries across both AWD and RWD versions covered here. Available choices stay focused on modern performance-oriented radial options from BFGoodrich in blackwall form. The key decision is less about size and more about selecting the right series, load specification, and intended driving character for the car you actually use.
Which Tire Size Is Right for The 2021 Lexus IS300
The 2021 Lexus IS300 uses one primary tire size: 235/45R18. It is a radial fitment for an 18-inch rim, and that same size applies to both the AWD and RWD sub-models covered here. With size fitment being straightforward, the real choice becomes which radial tire series best matches your driving style, wheel width, and preference for a modern blackwall performance tire.
In 235/45R18, the 235 identifies the tire's nominal section width in millimeters, 45 is the aspect ratio, R indicates radial construction, and 18 is the wheel diameter in inches. That makes it a modern low-profile radial size that suits the 2021 Lexus IS300's contemporary sport-sedan fitment. Available options in this size come from BFGoodrich across the g-Force Comp 2 AS, g-Force Sport Comp 2, and g-Force Phenom T/A series, all with blackwall styling. Choosing among them comes down to matching the tire's series character and rim-width compatibility to the actual wheels and road use of your IS300.
Fitment is straightforward across the covered 2021 Lexus IS300 sub-models because both use the same primary tire size. Checking the sub-model still matters when confirming the car's actual wheel setup, especially if it has been changed from stock.
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2021 Lexus IS300 (AWD)
The 2021 Lexus IS300 AWD uses the same 235/45R18 radial fitment as the other covered configuration. That keeps size selection simple, so the focus shifts to choosing the right BFGoodrich tire series and confirming that the wheel width remains within the tire's approved range.
The 2021 Lexus IS300 RWD also uses 235/45R18 radial tires on 18-inch wheels. With size fitment consistent, tire selection becomes a matter of comparing the available blackwall radial options and making sure the current wheel and suspension setup has not altered clearance.
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 2021 Lexus IS300 Tires for Sale
Available 235/45R18 choices for the 2021 Lexus IS300 center on BFGoodrich blackwall radial performance tires. The product grid lets you compare several g-Force series with similar 18-inch fitment, approved rim-width ranges, and related load and weight specifications.
These FAQs focus on the 2021 Lexus IS300's 235/45R18 fitment, 18-inch wheel requirements, available BFGoodrich radial choices, and the practical checks that matter before daily driving, spirited use, or replacing tires on a modified car.
Tire Size & Fitment
What tire size fits a 2021 Lexus IS300?
The 2021 Lexus IS300 uses 235/45R18 tires. This is a modern radial fitment on an 18-inch rim, and it applies to both the AWD and RWD versions covered here.
That makes size selection fairly simple, but the car still needs the right wheel setup to use that size properly. Before replacing tires, confirm that the Lexus still has 18-inch wheels and that any aftermarket wheel or suspension changes have not altered the width, offset, or clearance needed for a 235/45R18 tire.
What size rim does a 2021 Lexus IS300 use?
The primary tire fitment for the 2021 Lexus IS300 is built around an 18-inch rim. The tire size 235/45R18 itself confirms that wheel diameter, and the available products in this fitment are also made for 18-inch wheels.
Wheel diameter is only part of the fitment picture. The available 235/45R18 tires also have approved rim-width ranges, commonly spanning 7.5 to 9 inches in this application, so it is worth checking the actual wheel width before selecting a tire, especially on a car that may have replacement wheels.
Do all 2021 Lexus IS300 sub-models use the same tire size?
Yes. Both the 2021 Lexus IS300 AWD and the 2021 Lexus IS300 RWD use the same primary tire size, 235/45R18, and both use radial construction in this fitment.
Shared size fitment makes replacement easier, but it does not eliminate the need to inspect the car itself. A previous owner may have installed different wheels, altered ride height, or changed suspension components, so it is smart to confirm the current wheel diameter and width before ordering a replacement set.
Choosing the Right Tire
What should I consider when choosing a 235/45R18 tire for a 2021 Lexus IS300?
Start with the correct size, 235/45R18, and make sure the tire is suited to an 18-inch wheel within the approved width range. Since the available choices here are all radial blackwall tires from BFGoodrich, the main comparison points are tire series, load specification where shown, and the overall character you want from the car.
A daily-driven IS300 may lead you toward a different series choice than a car used more aggressively on dry pavement. It also helps to compare wheel width, tire weight, and any posted load figures so the tire you choose matches the way the sedan is actually driven rather than simply matching the sidewall size.
What brands offer tires for the 2021 Lexus IS300?
The available tires in this 2021 Lexus IS300 fitment come from BFGoodrich. Within the 235/45R18 size, the choices include multiple BFGoodrich g-Force series rather than a broad mix of different brands.
That means the decision is less about comparing competing brand identities and more about comparing tire series within the same brand. Looking closely at series names, rim-width approvals, weight, and any load information can help narrow the right match for an IS300 used for commuting, mixed driving, or more performance-focused road use.
What tire series are available for the 2021 Lexus IS300?
The 2021 Lexus IS300's 235/45R18 fitment is available in several BFGoodrich series, including g-Force Comp 2 AS, g-Force Sport Comp 2, and g-Force Phenom T/A. All are radial blackwall tires sized for 18-inch wheels.
Series differences matter because they help define the kind of tire you are putting on the car, even when the size is the same. A good comparison should include the series itself, approved wheel-width range, listed weight, and any load figure shown, then line those details up with how your IS300 is driven and set up.
Restoration & Appearance
Which tire should I choose for a period-style 2021 Lexus IS300?
A 2021 Lexus IS300 is a modern sedan, so period-style tire selection is less about vintage presentation and more about preserving the car's clean contemporary look. In this fitment, the available choices are all blackwall 235/45R18 radial tires, which suit the IS300's modern appearance naturally.
The better way to choose is to stay with the correct size and compare tire series rather than chasing an appearance theme that does not belong to the era. If the goal is an original-style presentation, keeping the proper overall fitment and avoiding mismatched wheel or sidewall combinations will usually matter more than small visual differences between tires.
Does correct tire fitment matter for a 2021 Lexus IS300 restoration or preservation project?
Yes. Even on a modern vehicle like the 2021 Lexus IS300, correct tire size and wheel compatibility matter if the goal is to preserve the car's intended stance, handling balance, and overall presentation. The primary fitment here is 235/45R18 radial.
A preservation-minded owner should avoid assuming that any 18-inch tire will look or work the same. Keeping the proper size, checking approved wheel width, and choosing a tire that matches the car's use helps maintain a coherent appearance and avoids the visual and clearance problems that can come from oversized or undersized replacements.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2021 Lexus IS300?
Yes. Even though the 2021 Lexus IS300 uses a straightforward 235/45R18 fitment, changes such as aftermarket wheels, altered offsets, suspension lowering, or replacement springs can affect how that tire sits in the wheelwell and how much clearance it has in motion.
That is why modified cars should be checked more carefully than untouched ones. Confirm the wheel diameter and width first, then inspect steering clearance, inner-fender clearance, and suspension travel with the car at ride height. A tire that matches the original size code still needs to work with the Lexus's actual wheel and chassis setup.
What should I inspect before driving a 2021 Lexus IS300 on new tires?
Before road use, inspect tire pressure, bead seating, tread and sidewall condition, valve stems, and wheel hardware. On a 2021 Lexus IS300, it also makes sense to verify that the new 235/45R18 tires are mounted on the correct 18-inch wheels and that the wheel widths fall within the tire's approved range.
A short initial drive should be followed by another visual check for rubbing, uneven stance, or any sign of air loss. It is also worth confirming alignment and general suspension condition, because fresh tires can reveal problems that were less obvious on worn ones, especially on a sedan driven enthusiastically.
How often should tires on a 2021 Lexus IS300 be inspected?
Tires on a 2021 Lexus IS300 should be inspected regularly rather than only when a problem appears. Frequent checks for pressure loss, irregular wear, cuts, bulges, and sidewall damage help catch issues early, especially on a car that sees mixed commuting and spirited driving.
Inspection is especially important after pothole strikes, wheel changes, alignment work, or any suspension modification. Looking at the tires every few weeks and before longer drives gives you a better chance of spotting wear or clearance problems before they become more serious, and it helps preserve the handling balance expected from the IS300.
