The 2018 Subaru WRX sits in the modern sport-compact tradition, blending turbocharged all-wheel-drive performance with everyday usability in a way that keeps owners attentive to both handling feel and appearance. Tire choice matters on this car because the WRX uses two different primary fitments depending on sub-model: 235/45R17 or 245/40R18, both in radial construction. That makes the first decision less about vintage-style construction and more about confirming whether the car is a Base, Premium, or Limited and matching the wheel diameter already on the car. From there, the real comparison comes down to brand, series, sidewall style, and how the tire suits street driving, seasonal use, or a more performance-focused setup.
Which Tire Size Is Right for The 2018 Subaru WRX
The 2018 Subaru WRX uses two primary tire sizes, and the correct one depends on sub-model as well as wheel diameter. The Base model uses a 17-inch fitment, while Premium and Limited models use an 18-inch fitment, so the first step is confirming the exact trim and checking the wheels currently on the car, especially if it has been modified or fitted with aftermarket rims.
In 235/45R17, the 235 identifies the tire's nominal section width in millimeters, 45 is the aspect ratio, R marks radial construction, and 17 is the wheel diameter in inches. This is a modern radial performance size used on the 2018 Subaru WRX Base, pairing a relatively short sidewall with a 17-inch rim. Available choices center on Blackwall tires from BFGoodrich and Nitto across series such as g-Force Sport Comp 2, g-Force Comp 2 AS, and NT555 G2. This size is the right place to focus if the car retains its 17-inch wheel setup and the goal is to balance proper fitment with the preferred driving character.
In 245/40R18, the 245 is the nominal section width in millimeters, 40 is the aspect ratio, R indicates radial construction, and 18 is the wheel diameter in inches. This size belongs to 2018 Subaru WRX Premium and Limited models and places the car on an 18-inch rim with a lower-profile modern performance fitment. Product choices include Blackwall options from BFGoodrich, Nitto, and M&H Racemaster, along with Pro-Trac Street Pro III versions in Redline and RWL sidewall styles. This is the size to evaluate when the car is on the larger factory-style wheel diameter and appearance or performance emphasis is part of the decision.
Sub-model fitment matters on the 2018 Subaru WRX because tire size changes with trim level rather than staying uniform across the lineup. Confirming whether the car is a Base, Premium, or Limited is the quickest way to narrow the correct size and wheel diameter before comparing specific tire options.
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2018 Subaru WRX Base
The 2018 Subaru WRX Base uses the 235/45R17 radial fitment on a 17-inch rim. That keeps tire selection focused on modern performance-oriented choices in the correct wheel diameter, with brand and series differences becoming more important than construction type.
The 2018 Subaru WRX Limited uses the 245/40R18 radial fitment on an 18-inch rim. Tire choice here centers on confirming the 18-inch wheel setup and then deciding among available performance-oriented options, including Blackwall, Redline, or raised white letter presentations.
The 2018 Subaru WRX Premium also uses the 245/40R18 radial fitment on an 18-inch rim. That means selection is less about finding the right construction and more about comparing tire series, intended use, and sidewall style within the proper size.
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 Subaru WRX Tires for Sale
Available 2018 Subaru WRX tire choices focus on 235/45R17 and 245/40R18 radial fitments, with BFGoodrich, Nitto, M&H Racemaster, and Pro-Trac represented. The product grid is most useful for comparing tire series, Blackwall versus Redline or RWL sidewalls, and rim-width compatibility within the correct wheel diameter.
These FAQs focus on 2018 Subaru WRX tire size by sub-model, 17-inch versus 18-inch rim fitment, available radial tire choices, sidewall styles, and the practical checks to make before road use or after modifications.
Tire Size & Fitment
What tire size fits a 2018 Subaru WRX?
A 2018 Subaru WRX uses one of two primary tire sizes: 235/45R17 or 245/40R18. The Base model uses 235/45R17, while the Premium and Limited models use 245/40R18. Both are radial tire fitments, but they are not the same wheel diameter, so the correct choice starts with the exact trim and wheel setup on the car.
That difference matters because a 17-inch tire cannot be mounted on an 18-inch wheel, and an 18-inch tire cannot be mounted on a 17-inch wheel. Cars that have seen wheel changes, winter wheel packages, or other modifications should be checked directly at the wheel before selecting a tire.
What size rim does a 2018 Subaru WRX use?
The 2018 Subaru WRX uses either a 17-inch or 18-inch rim, depending on sub-model. The 235/45R17 fitment uses a 17-inch rim, and the 245/40R18 fitment uses an 18-inch rim. The Base model is tied to the 17-inch fitment, while Premium and Limited versions use the 18-inch fitment.
Rim diameter should be confirmed before anything else because it determines which tire size family you can use at all. Wheel width also matters once the diameter is confirmed, especially when comparing performance tires with different approved rim-width ranges or when the WRX has aftermarket wheels.
Do all 2018 Subaru WRX sub-models use the same tire size?
No, 2018 Subaru WRX sub-models do not all use the same tire size. The Base uses 235/45R17, while the Premium and Limited use 245/40R18. That means there are two correct fitment paths within the same model year, and they are separated by both tire size and wheel diameter.
This is why trim identification is important before comparing tread design, brand, or sidewall style. A WRX that has been fitted with different wheels than its original trim package should be matched to the wheel actually on the car, not just the badge on the trunk.
Choosing the Right Tire
What should I consider when choosing a tire for a 2018 Subaru WRX?
Start with the correct primary size for the car: 235/45R17 for the Base, or 245/40R18 for the Premium and Limited. After that, compare the tire's intended use, construction details within the radial category, and the wheel-width range that matches your rims. On a performance car like the WRX, those basics matter before any appearance or brand preference.
Once the fitment is confirmed, the choice becomes more specific. Some owners want an all-season style of road use, while others want a more aggressive performance-oriented series or a distinctive sidewall treatment. Matching the tire to the car's actual wheel setup and how it will be driven usually leads to the best comparison.
What sidewall styles are available for 2018 Subaru WRX tires?
Sidewall style depends on the size and tire selected. The 235/45R17 options are Blackwall, while the 245/40R18 fitment includes Blackwall choices as well as Pro-Trac Street Pro III versions with Redline and RWL sidewalls. That gives 18-inch WRX owners more appearance variety within the proper fitment.
Appearance should still come after the correct size and wheel match. A sidewall treatment can change the visual character of the car significantly, but it should be compared alongside the tire series, rim-width compatibility, and the intended role of the car rather than treated as the only deciding factor.
What brands offer tires for the 2018 Subaru WRX?
Available brands for the 2018 Subaru WRX include BFGoodrich and Nitto in both primary fitments, with M&H Racemaster and Pro-Trac also appearing in the 245/40R18 size. Those brand choices span several tire series, so the comparison is broader than simply picking a name on the sidewall.
Brand should be considered alongside the actual product series, sidewall style, and wheel specifications. Two tires from the same brand may serve different purposes, and two different brands may overlap closely in fitment. The useful approach is comparing each tire within the correct WRX size rather than trying to rank brands in the abstract.
Restoration & Appearance
Which tire should I choose for a period-style 2018 Subaru WRX?
A period-style 2018 Subaru WRX still needs to begin with the correct modern radial size for the sub-model and wheel diameter already on the car. That means 235/45R17 for the Base or 245/40R18 for Premium and Limited. Once that is settled, the visual direction comes from the tire series and sidewall treatment rather than from changing to an older construction type.
For a clean contemporary look, Blackwall tires keep the presentation close to what most buyers expect from a late-model sport sedan. A 245/40R18 owner looking for a more customized appearance can also consider Redline or RWL options, while making sure the wheel and overall setup still suit the intended use of the car.
How does tire construction affect the appearance of a restored 2018 Subaru WRX?
On a 2018 Subaru WRX, construction is less of an appearance debate than it would be on an older collector car because the primary fitments are already modern radial sizes. The visual difference comes more from sidewall treatment, tread character, and overall stance than from choosing between bias-ply and radial construction.
That keeps the styling decision fairly straightforward: preserve the proper size and wheel diameter, then choose the look that fits the car's personality. Blackwall maintains a more understated modern appearance, while Redline or raised white letter options on the 18-inch fitment create a more customized and attention-grabbing presentation.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Subaru WRX?
Yes, modifications can affect tire fitment on a 2018 Subaru WRX. Aftermarket wheels, suspension lowering, altered ride height, brake changes, or body modifications can all change how much room the car has for a given tire. Even when the tire size matches a standard WRX fitment, the full package still needs to work with the car's current setup.
A modified WRX should be checked for wheel diameter, wheel width, and clearance at steering lock and full suspension travel before a tire is selected. Changes in offset or stance can matter as much as the tire size itself, especially on an 18-inch fitment with a lower-profile sidewall.
What should I inspect before driving a 2018 Subaru WRX on new tires?
Before driving a 2018 Subaru WRX on new tires, inspect the wheel size, verify the tire size matches the sub-model or current wheel package, and confirm inflation is set properly for the tire and vehicle application. It is also worth checking that there is no interference at the strut, fender liner, or steering components once the tires are mounted.
A short initial road check helps catch issues early. Listen for rubbing, feel for vibration, and recheck pressure after the tires have been in service briefly. On a performance-oriented car like the WRX, alignment condition and even tread wear matter quickly, so those should be monitored from the start.
How often should tires on a 2018 Subaru WRX be inspected?
Tires on a 2018 Subaru WRX should be inspected regularly, not just when tread looks low. Pressure, sidewall condition, tread wear pattern, and any cuts or bulges deserve routine attention, especially on a car that may see spirited driving or seasonal wheel changes. A quick visual inspection and pressure check are sensible habits throughout the year.
More frequent inspection is wise when the car has aftermarket wheels, suspension changes, or uneven wear from alignment issues. The WRX's fitment is size-specific by sub-model, so any sign of rubbing or unusual shoulder wear should prompt a closer review of wheel setup, inflation, and clearance before longer road use.
