Selecting The Right Tires For You

When do you need tires

The legal limit is 2/32 inch minimum tread depth.

In wet conditions 4/32 inch or less tread means a significant loss of wet traction due to shallower grooves and sipes.

In snow conditions, traction noticeably diminishes at 6/32 inch tread-depth; shallower lug and groove depths limit a tire’s ability to “bite” into snow and clean out snow compressed into the tread.

Irregular wear necessitates early tire replacement.

How Many Tires Do You Need

One tire due to irregular wear, defect or damage: replace with exact brand, line and speed rating and load capacity of the other three. Poor handling (pulling, instability) often occurs if you use a different tire.

Two tires due to poor/irregular wear: replace with same or better quality.

Replacing four tires is the best case: you are open to a wide range of options.

What Size

Most people replace their old tires with the same size that was on the vehicle. If this is your choice, see your owner’s manual or tire placard in the vehicle (see door or glove box locations) or the tire itself for the size. You can often improve ride and performance, however, by changing tire size.

By selecting a tire of the next lower profile, you can significantly improve the ride quality and handling of your vehicle. On small cars, a good example is to replace the original equipment 155/80R-13 size with 175/70R-13. The tread is almost an inch wider and the tire has a proportionately lower sidewall (however the tire’s height remains the same); both these features improve handling and stability.

Plus sizing, where a larger diameter wheel replaces the original equipment, has become very popular. In this application, the plus size tire is the same height as the original but its sidewalls are shorter. This change delivers the greatest improvement in tire response attainable. Plus sizing up to three inches is possible on many vehicles.

Selecting a larger tire is a common option, especially for van and truck owners; taller, wider tires can improve performance as well as ride quality. On trucks, larger tires can improve traction, load carrying capacity and appearance. Because cars and trucks are equipped with computerized systems (ABS for example) that use feedback from tire rotation, use these guidelines to select a larger tire.

1. For cars stay within 3 percent of the original equipment tire height. This is up to 3/4 inch taller tire for larger sizes.
2. For pick-ups and SUVs, a 15 per cent increase in tire diameter is usually acceptable. See your dealer for your vehicle’s specifications.

Think About Driving Conditions

Analyze your average driving conditions: dry roads most of the year, mixed wet and dry, or mostly wet. Then factor in seasonal extremes. Most tires purchased today are the all-season type that appeal to the great majority of drivers who seek acceptable performance and traction across the spectrum of possible driving conditions in all four seasons. Look for the M&S symbol on the sidewall to ensure the tire’s mud and snow rating for winter use.

Consider seasonal tires. All-season tires have performance and traction disadvantages since their design elements are averaged. In the fast-growing performance market segment two newer strategies have become popular. In non-snow climates, summer or dry type designs are emerging as year round favorites. Performance enthusiasts who live in more extreme winter climates also use these new designs when seasons allow and change over to winter tires once the snow begins to fly.

If you drive a pickup truck or SUV, chances are you’ll be considering a purpose-built tire design to match your driving needs. These designs have tradeoffs including traction (both on and off the road for various conditions), highway ride quality and, fairly recently, performance. In terms of traction, designs range from HT (highway tread) to AP (all-purpose) to AT (all-terrain) to MT (mud terrain) in order of aggressive tread design. Highway ride quality diminishes, as the tread design becomes more aggressive.

Obviously you can pick tread aggressiveness according to your needs; just be mindful of the highway ride quality tradeoff. Most SUV owners select AP type tires for their balanced highway ride and all-season traction. Sport Truck tires with all-season tread designs are quickly gaining popularity among SUV owners, however. They want sports car handling when on the highway and are willing to settle for less traction off-road. Pickup truck owners continue to sustain their “purpose-oriented” tire selection, with AT tires remaining the most popular type in this market segment. But here again, Sport Truck tires are showing gains among those who like great highway handling and need a tire that can handle truck load capacities.

Performance and Speed Ratings

Most people are aware of speed ratings. It is highly recommended that you buy a tire with the appropriate speed rating for your vehicle. In Europe replacing the original equipment tire with the same or higher speed rating is mandated by law. However in the US, you can buy a lower (and less expensive) speed rated tire of the same size. If you do this, be aware that you are limiting your vehicle’s performance in terms of handling and speed capacity. Generally speaking, a tire’s handling response is commensurate with its speed rating. Look at it this way, you’ll lose that crisp handling the manufacturer designed into the vehicle and you will not be able to safely achieve the speeds the vehicle was designed for if you use a lower speed rated tire than the original design. Conversely, you can improve your vehicle’s handling with a higher speed rated tire.