Upgrading Your Tires? Start Here

From bumper stickers to body kits, there are many ways to customize your vehicle, but few can make a bigger impact than upgrading your tires. It’s a popular practice among the 4×4 truck and SUV set, who often opt for larger tires to improve their vehicle’s traction and ground clearance. So can you put bigger tires on your vehicle? The answer is yes, but it’s not quite that simple. Whether it’s for improving performance or just a matter of pure aesthetics, there are lots of reasons a driver might choose to up their tire game, but there are a few factors that need to be taken into consideration before you go switching out the factory tires for a new set. So before you start wondering “Is there a tire shop near me?” you need to think about a few things first.

Using different size tires from the ones recommended for your vehicle can have a noticeable impact on vehicle stability, fuel economy, speedometer accuracy, and even safety, so it’s important to make sure you understand how it could affect your experience behind the wheel. Read on as we define terms like “plus sizing” versus “upsizing,” explore some common methods of upgrading tire size, and examine the pros and cons.

Tires 101

Increasing tire size can be achieved in one of two ways: plus sizing and upsizing. These methods might sound like interchangeable terms for the same activity but differ in one important way. Plus sizing involves installing larger wheels, not necessarily larger tires, whereas upsizing sees the tire size increase, but the wheel size remains the same. Each approach has its advantages and disadvantages, though plus sizing tends to be more about functionality and performance, while upsizing is often more of a style choice whose functional benefits don’t always outweigh the drawbacks. For this article, we’re going to focus largely on plus sizing, which is both the more common method and the one far less likely to result in some unexpected headaches down the road.

Before we get into some of the specifics, let’s do a quick refresher on tires, tire sizes, and wheels. First off, a friendly reminder that while the terms “tires” and “wheels” are often used interchangeably by the less automotive-minded, there are two separate components. Wheels are the solid metal cylinders affixed to your vehicle’s axle by large bolts, whereas the tire is the black, rubbery, high-traction surfaces that actually make contact with the road. “Rim” and “wheel” are also often confused, but the rim is actually just the outer edge of the wheel itself.

While the script stamped into the side of every tire might as well be in hieroglyphics for how difficult it is to decipher, we’ll keep it simple by focusing on the four basic metrics used to gauge tire size. A typical tire might read something like 245/40R18, which breaks down as follows:

• 245: Tire width in millimeters when measured at its widest point.
• 40: Aspect ratio, or the tire’s height as a percent of its width.
• R: Indicates radial tire construction. This is less applicable to the plus-sizing process as almost all tires feature radial construction.
• 18: The size of the wheel, in inches, that can accommodate the tire.

How Big To Go?

Plus sizing comes in several different levels, from “plus zero” up to “plus three,” depending on how big you’re looking to take it. Plus zero is probably the easiest version of plus sizing to wrap your head around, as it involves increasing just the tire size while keeping the wheels at their original factory specification. For example, going plus zero with a 205/60R16 tire would involve upgrading to a 215/55R16. If you refer to the tire number guide above you’ll notice that when going plus zero, the tire’s width increases by 10, while the aspect ratio shrinks by 5. This trade-off is important in order for a larger tire to fit on the same size wheel. While opting for plus zero will have the least dramatic impact, it can still provide a noticeable increase in traction and response due to the increased contact area and lower tread profile.

As we get into plus one territory, the wheel size starts to increase along with the tire size. This means that instead of a 17-inch wheel, you’ll need to upgrade to an 18-inch version while also investing in new tires. Like with the plus zero setup, section width will increase inverse to the aspect ratio, though the change is a bit more drastic here. That 205/60R16 tire will become a 215/50R17 as the width increases by 10, the aspect ratio decreases by 10, and the wheel gains one inch in diameter. Plus one tires can improve corners and handling but are often noticeably noisier and less comforting than plus zero or factory-installed considerations.

Plus two upsizing is much of the same, just amped up a little bit. Width increases by 20, the aspect ratio decreases by the same number, and the rim diameter gains two inches, so that 205/60R16 now needs to be 225/40R18. Again, drivers will notice an improvement in cornering and handling, but at the cost of noise and comfort.

At the upper end, plus three upsizing follows the same pattern as the plus one and plus two levels, with a 205/60R16 becoming a 235/30R19. These tires will provide an even less comfortable ride, though this is a fair trade-off for many drivers as plus sizing is often as much a style choice as it is a performance decision. The real risk when going plus three comes from potholes, frost-heaves, and curbs, which can wreak havoc on your wheels due to the narrower tire providing significantly less cushioning.

The Pros of Plus Sizing

Plus-sizing can go a long way in improving a vehicle’s look so let’s take a closer look at some of the pros of plus sizing your vehicle’s tires and wheels:

• Increased ground clearance: By definition, larger tires mean more space between the bottom of your vehicle and the road. This can provide a number of advantages, such as increased visibility and comfort, though many drivers who choose to plus size do so in the name of off-roading. Adding even just an inch or two to a vehicle’s height can make a big difference when it comes to safely navigating the rocks, mud, fallen trees, and whatever else the trail decides to throw at you that day.
• Increased traction and braking: When it comes to off-roading, there are two things you can almost never get enough of: traction and ground clearance. Plus sizing your vehicle’s tires and wheels can have a noticeable effect on both, with larger tires providing improved traction by increasing the amount of the tire that’s in contact with the road at any given time. This can also improve braking and safety since it decreases the amount of time it takes for the vehicle to come to a stop. There are other ways to improve a vehicle’s traction in off-road scenarios, such as investing in all-terrain or max-traction tires, but plus sizing remains popular.
• Improved handling and cornering: Thanks to the wider treads and stiffer sidewalls, plus sized tires can go a long way in improving both cornering and handling. This is particularly noticeable on tight turns where larger tires can help prevent “oversteering” or having the vehicle turn more than the driver intends.
• Aesthetics: For a certain type of driver, there’s just nothing as alluring as a vehicle with nice, big wheels. While it’s sometimes a matter of increasing performance, larger tires and wheels can also be a style choice. Not only do they add to the imposing nature of a pickup truck or SUV, but the larger wheels provide the perfect canvas for some high-end customization. Investing in a plus sizing project could go a long way in increasing your vehicle’s value among a specific set of buyers, which could make all the difference when it comes time to sell.

The Cons Of Plus Sizing

While plus sizing would appear to be an obvious choice in further upgrading your vehicle, it is important to consider these factors to see if plus sizing is the best option when it comes to customization:

• More expensive: Obviously, there’s going to be a cost associated with switching out your tires and wheel for an entirely new set, but that’s just the tip of the iceberg. Larger tires and wheels are, in general, more expensive than their smaller counterparts because they require more materials and, in some cases, different construction techniques. Then there are the unexpected costs. If the tires you’ve picked out are too big for your vehicle’s wheel well, you might have to invest in a lift or leveling kit to make them fit. Plus sizing can also void your manufacturer’s warranty, and as a general rule, larger tires will wear out and need replacement more often than smaller ones.
• Adjustments: In order for your vehicle to perform its best when rolling on plus sized wheels, there are a number of adjustments you’ll have to make to the vehicle itself. This may involve changing the vehicle’s TPMS (tire-pressure monitoring system) to fall in line with the recommended pressure of your new tires. Since larger tires will result in a speedometer reading that’s slower than your vehicle’s actual speed, tweaking the Electronic Control Module (ECM) to accurately reflect your speed and distance on the speedometer and odometer might also be in order.
• Lower fuel economy: The more of your tire that’s in contact with the road, the less fuel-efficient you’re going to be as the wider, deeper tread increases the vehicle’s rolling resistance. Larger tires are also heavier, increasing the vehicle’s overall weight and decreasing fuel efficiency. These same factors also make for a noisier driving experience.
• Worse handling: Increased height brings with it a higher center of gravity, which can affect your vehicle’s handling. This can result in less stability, which means drivers should be more careful when moving at higher speeds. Larger tires also take longer to rotate, add weight, and limit the movement of the vehicle’s drivetrain, which all take their toll on steering. Top speed and acceleration can also suffer, but if these trade-offs are worth it for the increased ride height and traction, you can proceed.

Ready To Plus Size?

Ready to experiment with plus-sizing? Make Thomas Nissan of Joliet your first stop. While customers have come to trust our team when it comes to finding some of the best deals on new and used vehicles from Nissan and more, many don’t realize that we also offer a full-service center complete with our own in-house tire shop featuring leading brands like Continental, Yokohama, and Bridgestone. There are lots of reasons to choose Thomas Nissan when it comes time to invest in a new pair of tires, starting with our team itself.

Our factory-trained technicians know every vehicle on the lot inside and out and are ready to offer their expert advice on how a new set of tires can help take that pickup, SUV, or even sedan to the next level. Their experience and expertise are especially helpful in avoiding some of the pitfalls and precautions unique to plus-sizing your tires and wheels. We also offer free 24-month road hazard coverage on certain tires, fixing or replacing any flat tire you might experience during your first two years of ownership. It’s just part of our commitment to customers that’s made us one of the most trusted, successful dealerships in the area, so stop by today and experience the Thomas Nissan difference.