Wider Tires: How Going Big With Rubber Affects Installation, Driving Feel and Performance
There's no question that wide tires look great. Whether you're driving a slammed sports car or a lifted truck or SUV, a wide tire provides attitude and style while also improving handling and acceleration on the street, or grip and control on the trail.
As with all things automotive you can't just slap on a set of wider tires without considering how it will impact your vehicle's performance. Tires are one of the most important components of a car or truck's suspension system, and installing a new set should be part of an overall plan that takes into account how they will change the driving experience.
Let's take a deeper dive into the world of wider tires and look closely at the main considerations when choosing what rubber to install under your automobile.
Contact Patch Plus
Aside from esthetics, there's one very compelling reason to slap on a set of wider tires: boosting the size of your contact patch. As the old cliché goes, tires are the only part of your car that actually touch the road, and you might be surprised to find out that the total area of rubber in contact with the asphalt is typically no larger than a single sheet of letter paper.
Naturally, a wider tire helps to solve this issue by stretching out that patch as much as possible. In turn, that gives your rubber a better chance at finding traction under acceleration, but also at maintaining grip while cornering, and digging in when your foot hits the brake. It's often one of the most cost-effective ways to improve your vehicle's overall performance and safety, and combined with the stylish look of a fatter tire, it's also a very popular modification to make.
Staggered vs. Square
There are two ways to deploy a wider tire strategy. The first is to choose a section width that meshes well with your front and rear suspension details and body work, and install a same-size tire at each of your car's four corners. This is called a 'square' setup, and it helps balance the contact patch between handling and acceleration for rear-wheel drive cars. It's also non-negotiable for all-wheel drive vehicles, which require the same tire diameter (which is a function of section width) at each corner in order to prevent damage to differentials.
You may also notice that some enthusiasts instead choose a much wider tire for the rear axles as compared to what they put up front. The theory behind this is that it gives you as much rubber as possible to transmit power to the pavement, thus ensuring excellent traction for higher horsepower, rear-wheel drive cars. It's especially common for anyone running drag radials or a tire with a wrinkle sidewall, which isn't needed at the front of the vehicle.
There are a few caveats to this strategy. You won't be able to properly rotate your tires, which can lead to increased wear, especially if you're regularly at the race track. Depending on your suspension setup, a wider tire at the rear can also introduce understeer into your vehicle's handling, so make sure that your suspension is aligned and dialed-in to alleviate that if at all possible.
There are a very few cars out there that used a reverse-staggered setup (wider tires at the front), but they are exceedingly rare from the factory. That being said, some front-wheel drive track, autocross, and drag cars can be found with this layout, almost always installed by a chassis builder or tuner who knows exactly how it will affect performance.
Wet And Wild (And Snowy, Too)
Wider tires offer excellent traction on dry pavement, but there are a couple things to keep in mind about how they can affect your driving experience. With larger treadblocks, a wider tire will transmit more 'information' about the surface you are traveling over, which means imperfections, rough roads, and bumps will be more noticeable. You may also encounter greater 'tramlining,' which is the term used to describe a tire being moved around by ruts or grooves in asphalt (a common side effect of using a much wider tire).
In wet weather, wider rubber can occasionally be a liability. Although the grooves in a wide tire are larger, allowing for better channeling of water away from the treadblocks, with more surface area the potential for hydroplaning when hitting standing water on the road is greater. On a snow-covered road, the increased surface area of a wide tire is less effective at cutting through the white stuff as compared to a narrower option, which is why some people choose to install a smaller tire during the winter months.
Roll Out, Or Cut Out
If you're installing a wider tire than what you car was originally designed to accommodate, you may encounter a situation where the rubber doesn't quite fit under the lip of your fender. Most of the time, a wider tire that needs rolled fenders will be installed on a vehicle that rides on a lowered suspension, which brings the fender lip even closer to the rubber.
The most common way to deal with this issue is to 'roll' the fender lip. Since it's usually the inner fender lip that is making contact with a wider tire, you need to use a roller, either a specialized tool that mounts to the hub, providing you with a controlled arc, or even a heat gun and a cylindrical hand-roller, to gently push it back away from the tire. By flattening the metal in this way, it prevents gouging of the tire, or damage to the fender due to suspension travel.
What if rolling still won't accommodate your wider tire? The next option is to install a set of fender flares. If you own an extremely low car and are using seriously wide tires, flares may be your only option. Likewise, if you're driving a lifted truck and want to install taller, wider mud or off-road tires, and are concerned about fender contact at full suspension compression, you'll also want to look at flares. This process is a little more involved than fender rolling, because you'll most likely have to cut metal from your wheel wells to accommodate the tire, and then conceal those cuts with the new flares.
Making Space
If you're installing a wider tire, you may also have to consider more than just its impact on your body panels. Depending on the offset of the wheel you are using, and the position of the suspension components, wheel spacers could be a part of the conversation, too.
Some wider tires look fine when the front wheels are pointed straight, but when the steering is turned at full lock they can come into contact with the vehicle's chassis. It's here that wheel spacers come in, adding extra millimeters between the wheel and the hub in order to provide you with the clearance that you need.
Keep in mind your application when shopping for spacers. You'll want to make sure that the parts you buy are strong enough for off-roading or high performance driving, as some spacers are simply intended for the 'hard parked' crew that won't be doing anything more strenuous than street driving.
You'll also want to consider adding longer aftermarket wheel studs, because as the spacers push your wheel away from the hub it also reduces the number of threads available for your lug nuts to grab onto. Some wheel spacers offer a bolt-on design that actually extends the hub, helping to strengthen your wheel's connection.
Naturally, if your tire is wide enough to require a large spacer, you'll most likely be incorporating either a flared or rolled fender to complete the installation.
Want to learn more about suspension setup? Check out our feature on the basics behind wheel alignment.
