Every Nissan vehicle’s original equipment (OE) tire features specific design choices that best fit it’s intended use. Nissan of LaGranges’s Service Team can help you choose the best tire for your Nissan, but here’s the lowdown of how to pick a tire if you want all the details.
The main design factors that come into play when selecting appropriate replacement tires include:
- Tire size
- Tread pattern
- Load index and performance rating
Every tire has a series of letters and numbers on the sidewall that define its size and construction. Nissan’s recommended tire size can be found within the Owner’s Manual and on a tire information label on the driver’s door jamb.
The “best” tread pattern for a tire depends on various factors, including the weather and road conditions in which the tire will be used and the performance expectations of the driver.
On a clean, dry road, a completely smooth tire provides the maximum grip because it puts the maximum amount of rubber in contact with the road. (This is why smooth tires are often used on racing cars.)
In the presence of even a little moisture, however, a smooth tire will suffer from hydroplaning. Hydroplaning occurs when water builds up in front of a tire and acts as a wedge, lifting the tire off the road surface.
To prevent hydroplaning, a tire must be able to displace water — as well as mud, snow, and other debris — that lies between it and the road surface. The tread pattern provides this drainage.
When a tire is rolling on a wet surface, the tread pattern is designed to perform three functions:
1. Channel away most of the water through large grooves in the tread. To provide maximum drainage, the large grooves in the tread pattern must be as straight as possible. This allows the water to channel through them unrestricted.
2. “Mop up” the remaining water through a series of smaller channels and slits in the tread (sipes).
3. Provide the actual grip.
The subtleties of tread pattern design have a significant effect on a tire’s performance. For example, if the large grooves in the tread pattern are perfectly straight for optimum water drainage, the tire’s ability to grip during acceleration and braking will be diminished. If, on the other hand, the tread grooves are set in a highly angular pattern for optimum grip during cornering, the tire’s ability to channel water and help prevent hydroplaning will be diminished.
Four Basic Types of Tread Patterns
The four basic types of tread patterns are all-season, all-terrain, high-performance, and winter tires.
1 . All-season
All-season tires are designed for both dry and wet surfaces and can usually handle some amount of snow. They feature a tread pattern designed to channel moderate amounts of water to help keep the tire from hydroplaning. All-season tires provide a balance of performance, ride comfort, and long service life.
All-terrain tires are intended for both on- and off-road use in a variety of weather conditions, including rain and snow. However, when used on dry pavement, all-terrain tires tend to be noisy and may wear more rapidly than all-season tires.
Traction in off-road conditions depends on a tire’s ability to penetrate shallow layers of mud or debris and grip any firm surface that lies beneath. In all-terrain tires, this is accomplished by using large grooves and channels in the tread design. These enlarged grooves usually form a “block” or “knobby” pattern that helps optimize tire grip during off-road acceleration and braking.
Because mud and debris tend to collect in the channels of a tire, an all-terrain tread design must be able to clean itself so that the tire can continue to perform effectively. This self-cleaning action relies upon centrifugal force as the tire rotates to “throw off” debris collected inside the tread. To maximize the ability to “throw off” debris, all-terrain tires are very tall, and their tread is as wide and deep as possible. The added height also helps the tire absorb shock from bumps and rocks.
High-performance or “summer compound” tires are designed to provide superb traction on dry pavement. They can handle moderate amounts of water on the road, but are not intended for use in snow.
Their limited water channeling ability maximizes rubber-to-road contact, increasing grip for added traction. For additional grip, high-performance tires also tend to use a softer tire compound (the chemical make-up of the tread material). This can further shorten overall tread life.
Winter tires are recommended when temperatures remain below 45 degrees F for most of the winter season. You won’t find these in LaGrange or most of Georgia and Alabama. Their special compound remains flexible in cold weather and their tread pattern contains a high proportion of sipes to enhance grip in snowy and icy conditions. Winter tires carry a unique graphic designation (a snowflake inside a stylized mountain).
Tread patterns can also be classified by the direction in which they are designed to rotate.
A symmetric tread pattern is a mirror image from left to right. This allows the tire to be mounted with either side out, on the left or right side of the vehicle. Symmetric tires can be rotated from position to position on the vehicle as desired.
The left side of the tread differs from the right side. Typically, one side of the tread is designed for enhanced cornering performance. The tire will be marked to show which sidewall must face outward. If the tires are rotated, these markings must be observed.
The tread is designed for only one direction of rotation. An arrow on the sidewall shows which direction is “forward.” Typically, directional tread patterns are the hallmark of a high-performance tire.
LOAD INDEX AND PERFORMANCE RATING
Additional information available from sidewall markings includes the tire’s load index and speed, or performance, rating.
- 109 = Load index, an indication of how much weight the tire can support when inflated to maximum recommended pressure. It is based on an index rather than actual weight, with higher numbers indicating greater load capacity. Typical load indexes for passenger car and light truck tires range from 71 to 110 (the 109 in our example indicates that this tire is capable of supporting 2271 lbs at the manufacturer’s recommended maximum pressure).
It is important to match or exceed the OE tire’s load index. While lower load-rating tires tend to be lower in cost, tires must be able to support the weight of the vehicle, passengers, and cargo. Load index is particularly important when selecting tires for electric vehicles, SUV’s, and trucks.
- V = Speed rating (more accurately “performance rating”) technically indicates that the tire, when properly inflated, is capable of sustained speeds up to the rating.
Calling this the “performance rating” will help customers better understand its importance. Besides being able to sustain a certain speed, performance ratings indicate a tire’s stopping, cornering, and heat dissipation qualities.
Performance ratings do not always increase with alphabetical order; for example, H is greater than T. Always check a rating chart when selecting tires to meet or exceed the OE rating. It’s important to meet or exceed the OE rating because different vehicles put different forces on their tires. The tires must be able to deal with these forces in order to provide OE levels of safety, ride quality, and handling.
- Lower speed-rated tires tend to be less expensive than higher-rated tires. Some aftermarket shops may undercut dealer pricing by specifying inadequate tires. Educating vehicle owners on the importance of performance ratings will help them get the proper tires for their vehicle, regardless of where they purchase.
Nissan of LaGrange, Georgia offers new Nissan cars, trucks, SUVs and crossovers to LaGrange, Newnan, Columbus, Auburn, the Valley, and Atlanta. We also offer Genuine Nissan Service and Maintenance in our Auto Repair Shop. Nissan of LaGrange should be your first stop for a new or used vehicle, oil changes using Genuine Nissan Oil Filters and factory recommended oil, brake service, car battery sales, tires, and auto glass replacement. Nissan of LaGrange where “You Come First!” Always open at http://www.nissanoflagrange.com.You can also reach us at 706-884-1744.