How do I check my tire tread?
Ready to talk about tire tread depth? Let’s dive in.
What is Tire Tread Depth?
The tread depth of the tire is a vertical measurement between the top of the tread and the lowest groove. In the U.S., tire tread depth is measured in 32nds of an inch. When tires are brand new, they have tread depths from 10/32 to 11/32.
What is a Tread Wear Indicator?
In the United States, tires are required by law to have easily recognizable tread wear indicators. As the tire tread wears down, it eventually becomes level with the tread wear indicator. At this point, the tire should be replaced. It has too little tread left to provide traction. If safety weren’t persuasive enough, keep in mind that it is also illegal to drive with bald tires.
When is Tread Depth Too Low?
The minimum legal limit is 2/32 of an inch. This doesn’t mean that tires are perfectly safe if they have 3/32 left of tread. This is simply the limit at which you won’t pass your state safety inspection. Your tires become incrementally less safe as the tread wears down.
What Does Tread Depth Affect?
When it comes to safety, your tires are literally where the rubber meets the road. Sufficient tire tread depth is necessary for safe turning and braking.
Low tire tread depth =
- Reduced stopping distance
- Less traction in snowy or icy conditions
- Increased risk of hydroplaning in wet conditions
- Increased risk of tire blowout
- Reduced acceleration power
- Decreased fuel efficiency
If you live wear it rains or snows frequently, consider replacing tires when they reach 4/32 of an inch. With worn tires, you are at risk of hydroplaning on wet roads. This is when the tire can’t channel the water through the grooves. The car rides along the top of the water instead of staying in contact with the asphalt. As such, the tires can’t respond to the steering system. If you have experienced it, you know how terrifying it can be. In icy or snowy conditions, low tread depth makes it harder to stop. You can also fishtail when accelerating or slide sideways when turning.
There are special considerations for driving in hot weather as well. If you are heading into summer and your tires are near the end of their lifespan, be aware that they wear down faster on hot roads.
How Do I Check My Tire Tread?
Easy peasy. All you need to check your tire tread depth is a penny. Insert the penny with Abraham Lincoln’s head upside down. If the top of Abe’s head is showing, it’s time for new tires. Tamara shows you how to do it in this video.
Be thorough when you measure your tread depth. Insert the penny in several places around the tire. It’s not uncommon to have uneven tread wear. Measuring in several places will compensate for this.
Why Does Tire Air Pressure Matter?
Having the proper air pressure in your tires is also critical. Tire air pressure is expressed as a number followed by PSI. This stands for pounds per square inch. 28 PSI means 28 pounds per square inch. It is a measurement of the force inside the tire applied to one square inch. You can check the recommended tire pressure for your car in your owner’s manual or on a sticker inside the driver’s side door. For most vehicles, it is around 32 PSI.
The Problems With Underinflated Tires
If your pressure is too low, your tires will wear out quicker. You will also get poorer gas mileage. This is because it’s harder for your engine to propel a vehicle riding on squishy tires. Low air pressure also results in a jerkier ride.
The Problems With Overinflated Tires
If you discover that your tires are too low, fill to the correct pressure. Don’t assume ‘more is better’. There are problems with overinflation as well. When a tire has too much air, it doesn’t have as much surface area in contact with the pavement. This makes it more difficult to handle. It also increases the risk of a blowout. At high speeds, a blowout can be deadly.
Tire Pressure Monitoring Systems (TPMS)
Since the early 1970’s the National Highway Traffic Safety Administration (NHTSA) and international counterparts were concerned about the dangers of low air pressure. They were seeking technology that could warn drivers. Evidence was mounting that underinflated tires were a factor in thousands of car accidents each year. At the end of the decade, the NHTSA was also motivated by the energy crisis. Tire air pressure affects fuel economy.
Tire pressure sensing technology became available in the 1980’s and was first used by Porsche on the 1987 Porsche 959. In the U.S., TPMS was federally mandated beginning with the 2007 model year.
There are two types of TPMS, indirect and direct. Direct pressure detectors are located on the tire stems. If the sensor detects a significant drop in pressure, it sends an alert to the engine computer. The indirect type uses the antilock brake system to detect low pressure by measuring wheel speed. Tires revolve at different speeds depending on air pressure. The indirect method is less reliable and has been largely phased out among manufacturers.
Let Chapel Hill Tire Serve Your Tire Needs
At Chapel Hill Tire, we have been providing professional automotive service to North Carolina drivers since 1953. We help our valued clients choose the right tire and protect their tire investment with alignment and wheel balancing services.
Need new tires in Chapel Hill, Raleigh, or Durham? Schedule an appointment at one of our seven service centers. Thanks for visiting our blog!