Most manufacturers recommend replacing the tires on car, truck, SUV or van with compatible tires based on the information printed on the tire's sidewall. The letter imprinted on the sidewall of the tire contains information about the tire's class, width, aspect ratio, construction and wheel diameter. These letters also indicate the tire's load index and speed rating.
Most people go with the recommended tire size found on the sidewall of the tires on their cars.
The sidewall of the tires that are on the car indicate the size, radius, ply and other information to match the new tires to the old. Going with the manufacturer's recommendations ensures proper tire fit, load balancing and maximum traction.
While it is important to choose tires that fit, some drivers opt for recommended tire sizes in seasonal tires for summer, winter or all-season driving. When selecting all-season or winter tires, drivers should look at the worst possible driving conditions that they may drive in, and select tires accordingly. Some drivers purchase a winter-driving set of tires for use in periods of inclement weather, switching them out for all-season tires during the non-wintry months of the year.
Select the highest quality tire possible, based on price. In general, higher quality tires cost more but last longer.