According to conventional advice, if the tire tread wears down to a groove length of only 2/32 inches (in some states this is the tire tread depth law), or if it is displaying the tread wear indicator bar, enter: New tires for your car.
However, with many tires, the driver loses great traction and braking ability sooner than that in rain or snow. Loss of traction is an alternative to having the vehicle stop for a penny, as the tires gradually wear out and many vehicle owners do not regularly check the tread depth or uneven wear. It may not be apparent until you slip on them.
New tires typically have a tread depth of 10/32 to 11/32 inches when new. In addition to the deep tread, grooves, and indentations on the sides of the tread allow water and snow to escape under the tire and maintain proper grip. As the tread wears down and the grooves and grooves get shallower, more water is trapped under the tire. The tires then roll over slippery water (“hydroplaning”) or snow instead of “biting” the pavement.
As a result, the stopping distance is greater, the wheel turns more when accelerating, and grip when cornering is reduced.
When this slip or skid begins to occur, and the severity of the lack of traction, depends on the design of the tire and can occur before it appears that there are broken tires that need to be replaced. For some tires, for example, if the tread depth is still 5/32 inches, it can be dangerous. This seems to be more than enough to avoid buying new tires. However, some tires have better traction on wet pavement and snow than others, keeping them for longer miles and less depth.
The mechanic will inspect the tire for abnormal or excessive wear, measure the depth of the tread with a gauge, and inform you of the tire’s remaining life. Depth gauges to check for worn tires are available at your own auto parts store. Also, there is always a penny test. Insert a Lincoln head penny (the top of the head should reach the headfirst) into the groove of the tread. If you can see the top of Abe’s head honestly, you need new tires.
Having the correct tire pressure is very important for good fuel economy and maximizing tire life. Your car has recommended tire pressures that give you optimal fuel economy, handling, and tire life, which is written directly on the vehicle door. This is what you should follow when filling air to the recommended pressure measured in pounds per square inch (psi).
For newer cars, the recommended tire pressure is most found on the label inside the driver’s door. If there is no sticker on the door, the specifications are usually listed in the owner’s manual. Most passenger cars recommend 32 psi to 35 psi for cold weather tires. The reason to check the tire pressure when the tire is cold is that when the tire rolls on the road, the friction between the tire and the road generates heat, which increases both the temperature and the pressure. To get the most accurate reading (not to mention the most consistent), make sure the car is stopped overnight or parked for at least a few hours.