DETROIT — If you're cutting corners by canceling cable or clipping coupons, it might seem natural to skip replacing your tires, too. Don't. Worn treads can be dangerous, especially when they lose their grip as you're trying to brake or steer around danger. It's true that replacement tires are pricier than in the past because they've grown taller and wider. But it's still prudent to put new rubber on the road before treads wear down too much. Here are four tips on how to get the most for your money when shopping for replacements. Tom Krisher, AP Auto Writer
When the tread depth reaches 2/32 of an inch, tires are worn out and need to be replaced, experts say. You can test their depth by sticking a penny in the tire grooves, pointing the top of Abraham Lincoln's head toward the rubber. If you can see all of his head, you need new tires because they don't have enough rubber left to stop or start safely. Tires also have "wear bars" that are perpendicular to the tread, so you'll see a stripe across the tread if they're worn out.
Start looking for tires when the tread depth reaches 4/32 of an inch, experts say. Put a quarter in the grooves like you did with the penny. If you can see all of George Washington's head, start tire shopping.
Match tires to driving needs
Figure out what you like and dislike about your current tires before you start shopping. Original tires are designed by the tire and auto makers specifically for your car, but you can switch depending on your needs.
Companies make tires for summer, snow and for all seasons, so consider the climate where you live. Bob Toth, manager of passenger tire marketing for the Goodyear Tire & Rubber Co., said he makes a list of pros and cons. Did the tires wear out faster than you thought they should? Did they slide when it rained? Were they noisy? Generally there's a tradeoff between handling, fuel economy and treadwear, and you need to come up with the best compromise for your needs. Tires that handle and stop better generally have softer rubber that grips the road better but wears out more quickly. But gripping the road can cut into fuel economy. Higher mileage tires with harder rubber don't handle as well but can get better mileage.
Toth suggests looking at Web sites for reviews from consumers and independent testers. He uses online store Tire Rack's site (www. tirerack.com) because the company performs its own tests and lists customer reviews.
Stick close to original tires, sizes and ratings
The outside diameter and width of the tires generally need to be the same as original tires, and the load-carrying capacity must be the same or better. If the diameter is too far off, new tires will make speedometers and other gauges inaccurate because they are set to a certain number of tire revolutions per mile. A different width can hurt the vehicle's handling. If the load capacity is too low, it could be unsafe or make tires wear faster.
Tire sizes are stamped on the sidewall like this example: 225/60-R15 89H. In this case:
225 is the width of the tire, in millimeters.
60 is the aspect ratio, or profile size. The higher the number, the taller the tire. Generally tires with low aspect ratios handle better, while those with higher ratios ride more smoothly.
R stands for radial, a description of the way the tire is constructed.
15 is the wheel diameter.
89 is load rating index that your tire dealer can translate into pounds.
H is the maximum speed rating. There are different letter codes, but H stands for 130 mph. Some of the most common are S (112 mph) and T (118 mph).
• There also are temperature and traction letter ratings stamped on the sidewall, determined by the manufacturer. These can be used to compare tires between brands. An "A'' tire is the highest rated. But numerical treadwear ratings vary by tire maker and can't be used for comparison purposes. A 100 rating is supposed to equal 30,000 miles, but Toth suggests looking at the mileage that the tire maker will guarantee as a better gauge of wear.
Be careful with cheaper brands
The tire quality can vary wildly in rubber compounds, tread design and the supporting structure. Prices also vary by size, ranging from around $50 for smaller tires to over $500 for certain high-performance tires. Goodyear's Toth says for safety reasons, it's best to stick with a major brand that has engineering expertise and backs its products.
But others say that lesser-known companies make good tires as well, so you can go with some off-brand tires, like Yokohama and Kumho.