Hey guys! So, you're cruising in a 2018 Subaru WRX Premium, a fantastic car known for its performance and handling. A key aspect of keeping your WRX performing at its best is ensuring you have the right tires. But, with all those numbers and letters on the sidewall, it can seem like a foreign language, right? Don't worry, we're going to break down the 2018 Subaru WRX Premium tire size and everything else you need to know about your tires, so you can make informed decisions. We'll explore the stock tire size, discuss alternative options, and offer some tips on tire maintenance. Let's get started!

The Stock Tire Size: What Came From the Factory?

First things first: what size tires did Subaru originally equip on the 2018 WRX Premium? The standard tire size for the 2018 WRX Premium is 235/45R17. Let's break down what these numbers mean, because understanding the code is the first step to becoming a tire pro. The 235 represents the tire's width in millimeters. So, your tire is 235 millimeters wide from sidewall to sidewall. Next, we have the 45, which is the aspect ratio. This number indicates the tire's sidewall height as a percentage of its width. In this case, the sidewall height is 45% of 235mm. Finally, the R17 signifies that the tire is a radial tire and fits a 17-inch wheel. That's right, the 2018 Subaru WRX Premium came standard with 17-inch wheels. Now, why is this important? Because when you need to replace your tires, you'll want to stick to the same size, or consider other options. The stock tire size is what Subaru engineers deemed best for performance, handling, and overall driving experience. Sticking to this size ensures your speedometer and odometer readings are accurate and helps maintain the car's intended driving dynamics. Keep in mind that tire size also impacts how your car looks. A proper tire size ensures that the tires fill the wheel wells appropriately, maintaining the vehicle's aesthetic balance. Also, the WRX Premium's suspension is tuned for this size; deviating significantly might alter its feel on the road. Remember, tire size is not just about the numbers; it's about the connection between your car and the road.

Why Stick to the Stock Size?

So, why is it usually a good idea to stick to the stock tire size? Well, Subaru designed the WRX Premium with this specific size in mind. They considered factors like handling, braking, and overall performance. Using the factory tire size ensures that your car's systems, like the anti-lock braking system (ABS) and electronic stability control (ESC), function as intended. Also, keeping the stock tire size can save you money. These tires are widely available, which often means they're more affordable than specialized sizes. It also makes finding replacements much easier and faster. Moreover, sticking to the factory size helps maintain the resale value of your car. Buyers often prefer cars with original equipment, and keeping the stock size demonstrates that you have maintained the vehicle as recommended by the manufacturer. So, unless you have a good reason to change, staying with the 235/45R17 is often the safest and most practical choice. It's a win-win: optimal performance and hassle-free tire shopping! Keep in mind that going to a different tire size can cause some issues. The speedometer reading may be off, or your car may not perform as well. This is because the overall diameter of the wheel and tire combination is changed, which affects the car's gearing and how it measures speed and distance.

Alternative Tire Sizes: Exploring Your Options

Alright, let's say you're looking for a little something different. Maybe you want better grip for track days, or perhaps you're after a wider stance. Are there other tire sizes that fit on the 2018 Subaru WRX Premium? The answer is: possibly! However, it's crucial to proceed with caution. The most common alternative is usually a 245/40R17, which provides a slightly wider tire and a slightly shorter sidewall. This can potentially improve grip, handling, and the overall look of the car. However, you need to ensure the tires don't rub against the wheel wells or any suspension components. Always check with a tire professional to confirm if a different size is compatible with your specific wheels and vehicle setup. If you're considering a change, carefully measure the wheel well clearance before making a purchase. Take into account any modifications you've made to your car, like aftermarket suspension components or spacers. These changes can affect what tire sizes work properly. Going wider can potentially improve your WRX's grip in dry conditions, enhancing acceleration, cornering, and braking performance. But remember, a wider tire isn't always better. It can reduce fuel efficiency and potentially increase road noise. Consider your driving habits and where you do most of your driving before making a switch. If you're unsure, it's always best to consult with a tire expert. They can give you personalized recommendations based on your needs and the limitations of your vehicle. Remember that any change from the stock tire size can influence the accuracy of your speedometer and odometer readings. This is because the overall diameter of the tire changes, which affects how the car measures speed and distance. It's essential to understand the implications before making a decision. The right tire size should enhance your driving experience, not hinder it. So do your homework!

Factors to Consider When Choosing Alternatives

When exploring alternative tire sizes, there are several key factors to consider to ensure you make the right choice. First, think about your driving style and the type of driving you typically do. Are you a track enthusiast who needs maximum grip? Or are you mostly commuting and prioritize comfort and fuel efficiency? Different tire sizes offer different advantages in various driving scenarios. Then there's wheel size. Make sure that any alternative tire size is compatible with your wheels. The wheel width is a major determinant of what tire sizes fit correctly and safely. Using an incorrect tire size on your wheels can lead to poor handling and potential tire failure. Also, think about the load index. Ensure the replacement tires have a load index that meets or exceeds the original tires. This rating indicates the maximum weight the tire can support at its recommended inflation pressure. Using a tire with a lower load index can compromise the car's ability to safely carry its weight. Don't forget the speed rating. This indicates the maximum speed at which the tire can carry a load. Choosing a tire with a speed rating at or above the original rating is crucial for safety and performance. Pay attention to the overall diameter of the tire. Changing this can impact the accuracy of your speedometer and odometer. It can also affect how your car's ABS and ESC systems function. Always do your research and consult with a tire professional to ensure the alternative size is a good fit for your car and driving needs.

Tire Types: Choosing the Right Rubber

Beyond size, you'll also want to consider the type of tire. This will have a significant impact on your driving experience. The 2018 Subaru WRX Premium is a car that benefits from high-performance tires. Here are some of the popular types:

• Summer Tires: Designed for optimal performance in warm weather. They offer excellent grip in dry and wet conditions but are not ideal for cold temperatures or snow.
• All-Season Tires: A good compromise, providing decent performance in various weather conditions. They're suitable for light snow but don't perform as well as dedicated summer or winter tires in extreme conditions.
• Winter Tires: Specifically designed for cold temperatures, snow, and ice. They provide superior grip and handling in winter conditions but should be swapped out when the weather warms up.

Summer tires are usually the best choice for maximizing handling and grip in warm weather. They have a softer rubber compound that offers increased traction. However, this softer compound makes them less effective in cold or icy conditions, and their tread patterns are designed for dry and wet surfaces, not snow. All-season tires offer a balance between performance and all-weather capability. They have a tread design and rubber compound that works well in both dry and wet conditions, as well as light snow. They're a practical choice if you experience varying weather conditions. Winter tires, on the other hand, are a must-have if you live in an area with heavy snow or ice. They have a special rubber compound that remains flexible in cold temperatures. They also have a tread pattern designed to evacuate snow and provide maximum grip on icy surfaces. The choice depends on your local climate and your driving habits. If you experience all four seasons, you might consider having separate sets of summer and winter tires. This ensures you always have the best tire for the conditions. When choosing a tire, consider your driving style, where you live, and the type of performance you're after. Don't hesitate to ask your local tire shop for recommendations. They can suggest tires that best suit your needs.

Understanding Tire Ratings and Markings

Deciphering tire markings can feel like reading a secret code, but it's important for understanding your tire's capabilities. Here’s a rundown of common tire ratings and markings: The tire size, like 235/45R17, is the most obvious marking. As we discussed, this indicates the width, aspect ratio, radial construction, and wheel diameter. Then there's the load index, a numerical code that corresponds to the maximum weight the tire can support at its recommended inflation pressure. Make sure the replacement tires have a load index that meets or exceeds the original tires. You'll also see the speed rating, which is a letter code indicating the maximum speed at which the tire can carry a load. Choosing a tire with a speed rating at or above the original rating is crucial for safety and performance. The tire's DOT (Department of Transportation) code, which begins with DOT, indicates the tire meets U.S. safety standards. It also includes the date of manufacture, a four-digit number. The first two digits represent the week, and the last two represent the year. It's usually a good idea to avoid tires that are more than a few years old. The UTQG (Uniform Tire Quality Grading) system provides ratings for treadwear, traction, and temperature resistance. This allows you to compare different tires based on their performance characteristics. Finally, look for the tire's maximum inflation pressure and load capacity on the sidewall. Remember, the correct tire pressure is essential for optimal performance and safety. Regular tire pressure checks can enhance both your ride quality and your tires' lifespan. Take the time to understand these markings to ensure you're choosing tires that meet your vehicle's requirements and your driving needs. These markings not only provide information about tire specifications but also offer insight into performance capabilities and safety standards.

Tire Maintenance: Keeping Your Tires in Top Shape

Proper tire maintenance is crucial for safety, performance, and extending the life of your tires. Here's what you need to know:

• Check Tire Pressure Regularly: Use a tire pressure gauge to check your tire pressure at least once a month, and always before long trips. The correct pressure can be found on a sticker on your driver's side doorjamb or in your owner's manual. Under-inflated tires wear out faster, reduce fuel efficiency, and can compromise handling. Over-inflated tires can lead to a rougher ride and uneven wear.
• Inspect Tires for Damage: Regularly inspect your tires for any signs of damage, such as cuts, bulges, or uneven wear. These issues can compromise your tire's integrity and lead to a blowout. If you find any damage, have the tire inspected by a professional.
• Rotate Your Tires: Tire rotation involves moving the tires to different positions on your car. This helps ensure that all tires wear evenly. Follow the rotation pattern recommended in your owner's manual. Rotating your tires can extend their lifespan and improve handling.
• Check Tread Depth: Use a tread depth gauge or the penny test to check the tread depth on your tires. If the tread depth is too low, your tires won't be able to effectively grip the road, especially in wet conditions. Replace your tires when the tread depth is worn to the wear bars. This is indicated by a narrow strip of rubber that runs across the tire's tread. These bars become visible when the tread is worn down.

Maintaining your tires doesn't require a lot of effort, but the benefits are huge. Proper tire maintenance will improve your car's handling, increase fuel efficiency, and ensure you get the most out of your tires. These simple habits can save you money in the long run and keep you safe on the road. Don't underestimate the impact of properly maintained tires on your vehicle's performance and safety. Tires are your car's only point of contact with the road. Taking care of them is essential for safe and enjoyable driving. Remember that your tires are an investment in your safety and the longevity of your vehicle. By following a few simple steps, you can keep your tires in great shape and ensure that you have a smooth and safe ride. These maintenance practices also contribute to the overall performance of your vehicle, enhancing handling and improving fuel efficiency. This attention to detail reflects a responsible approach to vehicle ownership and ensures you get the most out of your tires.

The Penny Test: A Quick Tread Depth Check

The penny test is a simple way to quickly check the tread depth of your tires. Here's how to do it: Insert a penny into the tread groove with Lincoln's head facing down. If you can see the top of Lincoln's head, your tread depth is less than 2/32 of an inch, and you need to replace your tires. If part of Lincoln's head is covered by the tread, your tires are still safe. This is a good way to give you a general idea of your tires' condition. The penny test is a quick and easy way to check your tires' tread depth at home. It's an excellent way to determine if your tires are safe and ready for the road. The test is a reminder that regular tire checks are essential for safe driving.

Conclusion: Making the Right Tire Choice

Alright, guys! We've covered a lot of ground today. From the 2018 Subaru WRX Premium tire size (235/45R17) to alternative sizes, different tire types, and essential maintenance tips. Choosing the right tires is essential for maintaining your car's performance and ensuring a safe and enjoyable driving experience. Whether you stick with the stock size or consider an alternative, always prioritize safety and performance. Regularly check your tire pressure, inspect for damage, and rotate your tires to ensure even wear. With the right tires and proper care, you can keep your 2018 Subaru WRX Premium performing at its best for years to come. Remember that your tires are not just about the numbers; they're about the connection between your car and the road. Drive safe, and enjoy the ride!