Simple Answers from Greentech Automotive for Santa Rosa: Tire Tread DepthMay 6th, 2017
How can I tell when my tires are worn so much that they need to be replaced?
Greentech Automotive Answer:
That is question for Santa Rosa drivers. As we discuss the matter, keep in mind that one of the jobs of your tire tread is to move water. The channels in the tread act as passages for water to escape from underneath the tire. The deeper the tread, the deeper the channel – and the more water that can be evacuated.
When enough water can't be moved from underneath the tire, the tire can ride on the water – often called hydroplaning. The tire is literally not contacting the road but rather is “floating” on the water, so there is little traction and the vehicle can slide.
So somewhere between a brand new tire and a bald tire lies the point at which the tire should be replaced. Some governmental jurisdictions have minimum tread depth requirements for tires; others do not. So check the laws where you live in CA to learn the legal minimum.
Tire manufacturers are required to mold a tread wear bar into the tire. This bar appears across the tread when the tire is worn down to 1.6 mm (2/32 of an inch). Santa Rosa drivers can easily do the coin test. In the US, insert a penny into one of the grooves with Lincoln's head pointing down. If you can see the top of Lincoln's head, your treads are very worn and the tires need replacing.
In Canada, use a quarter with the caribou's head pointing down. If you can see the tip of the nose of this great northern animal, it is a sign of very worn treads. That means it is high time to bid adieu to your tires.
Studies have shown, however, that there is difference in stopping distances for in wet Santa Rosa conditions with tires that have less wear. For example, in controlled, wet conditions a vehicle with 3.18 mm (4/32 of an inch) of tread traveling at speeds was able to stop in about 26 metres (85 feet) less distance than the same car with tires with 1.6 mm (2/32 of an inch) of tread. That could easily be the difference between a safe stop and hitting the vehicle in front of you.
Santa Rosa drivers can gauge 3.18 mm (4/32 of an inch) by inserting a US quarter upside down into the tread. If it covers George Washington's head, you have more than 3.18 mm (4/32 of an inch) of tread.
New tires are a big ticket item for Santa Rosa drivers, so it's natural to want to get as much value out of them as possible. Just remember that a huge part of that value is the ability to stop safely in wet Santa Rosa conditions. You can with your friendly and knowledgeable Greentech Automotive tire professional for help with tire replacement.
Give us a call.
501 Barham Ave
Santa Rosa, CA 95404