The tires on your vehicle are reaching the end of their useful life. But what do you do next? How do you make an educated choice about which tires to purchase? Use this guide to help you the next time you are in the market for new tires.
The first thing you should know is the size of tire you need. You can find the tire size on the inside frame of the driver’s side door or on the sidewall of your tire.
The first three-digit number in a tire size is the width from sidewall to sidewall in millimeters. A tire with the size 255/55 R18/82S has a width of 255 millimeters.
After the slash mark, the two-digit number is the aspect ratio, which measures the tire’s cross-section to its width. In the example above, the 55 means the height is 55% of the tire’s width. The larger the aspect ratio, the larger the tire’s sidewall will be.
The next part of the tire size is a letter, either R for Radial or B for Bias. Radial means the layers of the tire run in straight lines across the tire. Bias means the layers run diagonally across the tire.
The two-digit number after the letter is the wheel size or the diameter of the rim. In the example of 255/55 R18/82S, the wheel is 18 inches in diameter.
The next two-digit number shows the load rating or the maximum weight that the tire can support when it has been inflated. The 82 in our example would be the load rating, and it would mean the tires have a maximum capacity of holding 1,047 pounds. The higher the load rating, the greater load-carrying capacity the tires have.
The last letter in the tire size indicates the maximum speed at which the tire can perform optimally. In the 255/55 R18/82S example, the S would indicate the maximum speed for this vehicle is 112 mph.
Seasons and Driving Condition
The next factor to consider in your tire buying process is the type of weather you will be driving your vehicle through.
- Summer tires. These tires are good for three of the four seasons. They do well to provide traction in dry and wet weather when the temperature is moderate or warm. They have a sharp steering response and stop your vehicle quickly. But summer tires work best at temperatures above 40° F. When the temperature gets closer to freezing (or below), the tires can behave inconsistently and lose their grip.
- Winter tires or snow tires. These tires provide excellent traction in snow and icy or slippery conditions. They perform better than any other type of tire in snowy weather conditions, but when warm weather hits, they don’t handle wear as well. If you live in an area with a long winter season, you might consider buying a set of winter tires to swap out your existing tires with when the temperatures cool.
- All-season tires. Most vehicles use all-season tires, which facilitate quality driving in most weather conditions. They are, however, subpar to winter tires when it comes to having enough traction to drive in the snow.
Two numbers can help you gauge how many miles a new set of tires is likely to provide. The tread-wear rating is listed on the tire sidewall, and the higher the number, the longer the tire should last. The tread-life warranties offered by the manufacturer can give a better estimate of how far these tires will take you.
When you are needing new tires, you can either replace the ones you had straight across (same style, brand, etc.), or you can choose to upgrade. Here are some things to consider if you want to upgrade your tires.
- You can upgrade to high-performance tires instead of standard tires straight across if you find the same size.
- The diameter (or two-digit number after the letter) must remain constant. This cannot be changed.
- Lower profile rubber will almost always require a larger-diameter wheel.
- Wider, low-profile tires are more prone to damage and wear down faster. They also make the car ride rougher and the steering harder.
If you are considering your upgrade options, it is best to consult a tire expert to ensure the tires will be compatible with your vehicle and that they will provide the quality of driving you need for your circumstances.
If you are in the market for not only new tires but also a new car, check out our inventory of used branded cars online (for delivery nationwide) or in-person in Salt Lake City, Utah. In addition to being a used car dealer, we also offer a wide range of services in our auto shop. Contact us for help with any car needs you may have.