EmailFirst, experts say you must understand the kind of tire you need. Regular and high-performance all-season tires will satisfy the largest percentage of consumers, but models for SUVs and other trucks are different than those for cars and minivans. Ultra-high-performance summer tires are appropriate only if you're willing to sacrifice all-weather versatility, tread life and price to improve your car's acceleration and handling.
Choose a tire type and size to suit your vehicle and driving conditions:
- Standard all-season tires are best for most people. These tires offer overall good traction (especially in dry conditions), long treadwear and a comfortable ride at a reasonable price. They lack the precise handling and grip of performance all-season tires. Treadwear is between 40,000 and 100,000 miles, and wheel sizes generally range from 14 to 18 inches, with S and T speed ratings.
- High-performance all-season tires are best for those who want better handling and grip without giving up too much comfort and wear. Treadwear is 40,000 to 70,000 miles, and these tires are appropriate for wheel sizes from 15 to 20 inches. They carry speed ratings of H and V.
- Ultra-high-performance tires are for those who want the best wet and dry braking and handling at the expense of tread life. Summer versions are not appropriate for snow or ice. Most models have no treadwear warranty at all. Wheel sizes range from 15 to 22 inches.
- Match new tire specifications to those of your existing tire. You'll need a tire that fits your existing wheels and has an adequate load rating for your vehicle. You'll find these specifications on your existing original tires or in your vehicle's manual.
Understanding tire sizes and speed ratings
Tire sizes are represented by a ratio followed by a whole number. The ratio comprises the width in millimeters and the percentage of that width that makes up the profile (the distance between the rim and the outer edge of the tire); the whole number is the rim diameter in inches. A tire with a size of 215/60-16 is 215mm wide, 129mm (60 percent of 215) from the ground to the rim and is intended for a 16-inch wheel.
Tire manufacturers use letters to represent the maximum speed at which a tire should be driven. There are about twenty different speed ratings, but the most common are Q (up to 99 mph), S (up to 112 mph), T (up to 118 mph), H (up to 130 mph), V (up to 149 mph) and Z (149 mph and above). Some Z-rated tires have an extra rating to show that they can handle even faster speeds: W (up to 168 mph) or Y (up to 186 mph). Experts say that even if you have no intention of driving at speeds of 130 mph or more, tires with a high speed rating are also better performers at more mundane speeds. While snow tires and most all-season tires perform well with Q, S or T speed ratings, performance tires should have at least an H speed rating.
Be cautious when considering plus-sizing
The latest trend is "plus-size" tires and wheels. Drivers buy larger wheels and shorter, wider tires. For example, if your car specifies a wheel size of 16 inches, increasing wheel size by one inch would result in a 17-inch wheel or "Plus One" for your vehicle. The tire you buy will then need to have a shorter sidewall, and usually a wider tread, to accommodate the same load and tire diameter.
Although many drivers are doing this for cosmetic reasons -- a larger wheel and narrower tire has a sportier look -- some experts say you can gain traction and handling by plus-sizing, because a wider tire can get a better grip. However, Consumer Reports magazine says Plus One gains you the most benefit at a lower price. Increasingly larger Plus Two or Plus Three wheels and wider tires cost exponentially more and offer less performance gain over Plus One.
There are many considerations that will factor into a decision to plus-size. First, your car must be able to accommodate the additional offset of a wider tire. You must be sure that the tire's load rating is at least the same as your factory-specified tire. Also, the narrower the tire's sidewall, the more susceptible you are to pothole and curb damage, since wheels can more easily become damaged without the extra rubber. Experts advise buying from a dealer/installer with experience in plus-sizing, who can identify the appropriate size options for your car.