2018 Subaru Tire Fitment Guide

2018 Subaru vehicles use 12 different tire sizes across six model lines. BRZ uses 215/45R17 and 215/40R18; Impreza uses 205/55R16, 205/50R17, and 225/40R18; Legacy uses 225/55R17 and 225/50R18; Outback uses 225/65R17 and 225/60R18; WRX uses 235/45R17 and 245/40R18; and WRX STI uses 245/35R19. Rim diameters span 16, 17, 18, and 19 inches, so there is no single Subaru-wide size for the year.

That means the first fitment check for a 2018 Subaru is always the model, followed by the wheel diameter already on the car. A BRZ owner choosing between 17-inch and 18-inch tires faces a different decision than an Outback owner comparing 17-inch and 18-inch utility fitments. Once the model and wheel diameter are confirmed, you can narrow the choice to the right section width, aspect ratio, and product style for the way the car is used.

On a 2018 Subaru, 215/45R17 is a metric radial tire size. The 215 is the tire's nominal section width in millimeters, 45 is the aspect ratio, meaning the sidewall height is 45 percent of that width, R identifies radial construction, and 17 is the wheel diameter in inches. For 2018 Subaru applications, that size belongs to the BRZ.

Reading the code correctly matters because a 215/45R17 is not interchangeable with a 215/40R18 even though the section width is the same. The rim diameter changes from 17 inches to 18 inches, and the lower 40-series profile changes the tire's proportions. If your BRZ has 17-inch wheels, stay with a 17-inch fitment first, then compare the available radial products in that exact size.

No, 2018 Subaru models do not share a single tire size across the range. The BRZ, Impreza, Legacy, Outback, WRX, and WRX STI each use their own fitments, and every size in the lineup is tied to a specific model rather than covering the entire year and make. Even within one model, more than one size can appear depending on wheel package.

That is especially important for Subaru because the brand's 2018 range included very different vehicles, from a compact sports coupe to a lifted wagon and a high-performance sedan. A buyer who only knows the year and make can still end up several sizes off. Before selecting a tire, verify the model and then compare the existing sidewall marking or wheel diameter against the correct Subaru fitment range for that model.

Most 2018 Subaru tire sizes here are available as Blackwall radials, which is the standard contemporary look for late-model Subaru applications. Two sizes expand the appearance choices: 205/50R17 for the Impreza is available in Blackwall and Wide Whitewall, and 225/55R17 for the Legacy is also available in Blackwall and Wide Whitewall. The Outback's 225/65R17 appears in an RBL sidewall style.

For a stock-looking 2018 Subaru, Blackwall is generally the most natural visual match because it aligns with the period and market positioning of these cars. Whitewall options on sizes such as 205/50R17 and 225/55R17 appeal more to custom styling than factory-correct restoration. If appearance matters as much as fitment, choose the correct size first, then decide whether you want a modern OEM-style sidewall or a more individualized look.

2018 Subaru tire sizes are covered by BFGoodrich, Michelin, Nitto, American Classic, and M&H Racemaster. BFGoodrich appears across the widest range of Subaru fitments, while Michelin appears in 205/55R16, Nitto appears in several sport-oriented 18-inch and 19-inch sizes, American Classic appears in 205/50R17, and M&H Racemaster appears in 245/40R18. Brand availability changes by size, not just by model.

That matters because a BRZ, WRX, or STI owner may have multiple brand choices in the same size, while an Outback running 225/65R17 has a much narrower path. The practical approach is to identify the exact size first and then compare the brands that exist in that fitment. Once you do that, you can sort by intended use, whether that is everyday street driving, a more aggressive performance feel, or a specialized application.

In 245/40R18 for the 2018 Subaru WRX, BFGoodrich and Nitto both offer Blackwall radials, but their spec details are not identical. BFGoodrich options include W-rated and Y-rated versions, with rim width ranges generally spanning 8.0 to 9.5 inches and load figures up to 1,609 pounds at 50 psi on some products. Nitto's NT555 G2 is W-rated to 130 mph, carries a 1,609-pound maximum load at 50 psi, and also fits an 8.0 to 9.5-inch rim range.

The comparison comes down less to basic fitment than to the kind of product you want within the same size. A buyer deciding between these brands should compare the exact speed rating, intended use, and wheel width on the car rather than assuming every 245/40R18 behaves the same. That is especially important on a WRX, where the 18-inch package sits squarely in the performance side of the Subaru lineup.

Rim width requirements for 2018 Subaru tires vary by size. 205/55R16 and 205/50R17 fit 5.5 to 7.5-inch rims; 215/45R17 fits 7.0 to 8.0-inch rims; 215/40R18 fits 7.0 to 8.5-inch rims; 225/40R18 fits 7.5 to 9.0-inch rims; 225/55R17, 225/50R18, and 225/65R17 fit 6.0 to 8.0-inch rims, with one 225/55R17 whitewall extending to 9.0 inches; 235/45R17 fits 7.5 to 9.0-inch rims; and 245/40R18 plus 245/35R19 generally fit 8.0 to 9.5-inch rims.

Those ranges show why the tire size alone is only part of the fitment picture. A wheel can have the correct diameter but still fall outside the ideal width for a given tire. Before ordering, confirm the exact wheel width on the car and compare it to the acceptable range for the specific tire you want, especially on WRX and STI applications where wider wheels and lower-profile tires are common.

2018 Subaru tire fitments here are radial applications, and at least one size includes an explicit tubeless marking. The Michelin 205/55R16 carries a TL designation, while many of the other Subaru-size products do not spell tube status out in the size marking. There is no sign here of a dedicated tube-type Subaru fitment in the 2018 range.

For most late-model Subaru wheels, the normal expectation is a tubeless radial setup, but the final check should always be made against the wheel design and the exact sidewall marking on the tire you choose. That is more important after wheel swaps, aftermarket refinishing, or custom builds. If the tire and wheel do not clearly point to a standard tubeless arrangement, have the combination reviewed before mounting.

A 2018 Subaru stored with its tires fitted should be kept in a cool, dry, dark space away from direct sunlight, electric motors, welders, battery chargers, and other ozone-producing equipment. Maintain the tires at proper inflation and keep the car off damp soil or bare concrete for long stretches when possible. Because all of the Subaru fitments here are radial, they generally tolerate storage better than older bias-ply tires, but they still age from environment as much as mileage.

For seasonal storage, roll the car periodically so one section of tread does not carry the load continuously. If the Subaru will sit for an extended period, tire cradles or properly placed stands can reduce stress on the casing while protecting the suspension and wheel finish. A little storage discipline goes a long way, especially on lower-profile WRX, STI, and BRZ fitments that are more sensitive to pressure loss and impact damage.

On a 2018 Subaru, age is usually a better guide than mileage for replacement planning, especially on enthusiast cars or lightly driven seasonal vehicles. A good rule is to start evaluating tires closely once they reach five to seven years of age and to treat about 10 years as the outer limit for serious continued use. The DOT date code on the sidewall tells you when the tire was built.

That matters because a WRX STI or BRZ might wear low-mileage tires that still look decent but have already aged beyond their best years. Exposure to sun, heat cycling, and long periods of inactivity can shorten useful life even before tread depth becomes an issue. If a tire is aging out, replace it based on condition and date rather than waiting for obvious wear alone.

Tires on a 2018 Subaru should be checked before every drive and given a more thorough inspection before any longer trip. Look for sidewall cracking, cuts, bulges, uneven tread wear, punctures, and signs of pressure loss. Lower-profile sizes such as 245/35R19 and 245/40R18 also deserve a close look for impact damage from potholes or curb contact.

Regular inspection is especially helpful on all-wheel-drive Subarus, since major tire condition differences can affect how evenly the car operates. Use a gauge rather than a visual guess, and pay attention to any vibration, pull, or sudden change in road feel. If one tire shows irregular wear, inspect alignment and suspension components before fitting another set so the replacement does not wear the same way.

Yes, the 2018 Subaru tire sizes here are highway-capable when the tires are in good condition and used within their ratings. Most of the sport-oriented sizes carry W speed ratings, which are rated to 130 mph, one 205/55R16 Michelin carries a Y rating to 186 mph, and the Outback's 225/65R17 BFGoodrich all-terrain tire carries an S rating to 112 mph. Those limits are well above normal U.S. highway speeds.

Real-world safety still depends on more than the letter rating. Inflation, age, damage, alignment, load carried, and the Subaru's overall mechanical condition matter just as much, especially on performance models that invite spirited driving. For highway use, make sure the tire size matches the model, the speed rating suits the intended use, and the tires have been inspected recently rather than relying on appearance alone.

Inflation pressure for a 2018 Subaru should follow the vehicle placard or owner's manual first, because Subaru set its recommended pressure around the car's weight distribution, suspension tuning, and intended use. Tire product ratings show the pressure tied to each tire's maximum load, not the everyday operating pressure for every Subaru. Examples include 1,356 pounds at 50 psi for some 215/45R17 tires, 1,819 pounds at 50 psi for one 225/55R17, and 2,150 pounds at 65 psi for the 225/65R17 all-terrain tire.

Those numbers should not be transferred from one size to another or treated as a blanket setting for the whole 2018 Subaru range. A BRZ, Outback, and WRX have different needs even when their tires look broadly similar. Use the tire's rated pressure as a capacity reference, then set the car according to Subaru's specifications unless a tire manufacturer gives a specific adjustment for that exact product and application.

Before a longer drive in a 2018 Subaru, inspect all four tires for cracking, cuts, punctures, sidewall bulges, abnormal tread wear, and correct cold inflation pressure. Check the spare as well, since many owners discover an underinflated or neglected spare only after a roadside problem. On lower-profile BRZ, WRX, and STI sizes, also look closely for wheel lip damage that can follow pothole impacts.

Tires are only one part of the pre-drive picture on a modern Subaru, so fold that inspection into a broader look at brakes, fluids, battery condition, and alignment behavior. If the car has been sitting, a short local test drive before a highway trip can reveal vibration, pull, or pressure loss while you are still close to home. Catching those issues early is far easier than sorting them out mid-trip.