How do I know when my tires need to be replaced?

Caring for Your Hardworking Tires

Bald heads are OK. Bald tires are not. The tread on these rubber road-huggers isn't looking good.
Bald heads are OK. Bald tires are not. The tread on these rubber road-huggers isn't looking good.
© iStockphoto/seraficus

In some cases, just paying attention to your car when you drive can clue you in to problems with your tires. For instance, if your car vibrates excessively, your tires might be unbalanced or out of alignment. If you start to feel that your car's handling is unresponsive, check to see if your tires are underinflated. If your car seems particularly bumpy, on the other hand, they might be overinflated. Proper alignment, balancing and inflation can greatly improve your car's handling and extend the life of your tires.

To further extend the mileage you get from your tires, have your tires rotated every 7,000 miles (11,265 kilometers) or so, or consider doing the job yourself if you've got a jack and jack stands. Rotating your tires will ensure that they wear evenly, so you'll get the most out of them before you need to head to the tire store.

Lastly, make sure to avoid potholes and other road debris if you can, since those things can knock your tires out of alignment or damage the tires themselves. Considering that the average cost of a replacement tire has jumped nearly $40 over the past ten years, all the way up to $97.97 per tire, getting more mileage out of your tires makes a lot of sense [source: Welsh].

But what happens when you have a tire with lots of life left on the tread, and you happen to run over a sharp rock or nail on the way home from work? Should you fix the flat yourself, take it into a professional or get it replaced? The answer depends on several factors. If the puncture is located on the tire's sidewall, you're out of luck; you're going to need a new tire. If the puncture is located in the tread of the tire, however, your safest bet is to take the tire into a professional, who will take the tire off the wheel, patch the tire from the inside and plug the hole. This option might be a bit pricier than buying a $5 tire plug kit and doing the job yourself, but the repair will be much stronger. In fact, a study of more than 14,000 scrap tires showed that, while 17 percent of tires had been repaired during their life, only 12.5 percent of those repairs were performed correctly [source: Rubber Manufacturers Association]. Considering all that's riding on your tires, a few extra bucks is a small price to pay for a safe ride.

Keep reading for more links on taking care of your ride. 

Related HowStuffWorks Articles


  • Consumer Reports. "Tires: Big Grippers." Nov. 2007.
  • Consumer Reports. "Tire Safety." (10/15/2009)
  • Department of Transportation. "Many U.S. Passenger Vehicles Are Driven on Under-inflated Tires, NHTSA Research Survey Shows." August 29, 2001. (10/15/2009)
  • "Car Talk Service Advice: Tire Pressure." 4/29/2005. (10/15/2009)
  • Magliozzi, Tom. & Ray. "Cart Talk: When to plug, patch or just buy new tires." Seattle P-I. July 11, 2003. (10/15/2009)
  • Marinucci, Carla. "Tire gauge pumping up campaign rhetoric." San Francisco Chronicle. August 5, 2008. (10/15/2009)
  • National Highway Traffic Safety Administration (NHTSA). "Tire Safety: Everything Rides On It." (10/15/2009)
  • Rubber Manufacturers Association. "Tire Industry Study: Chronological Age Alone Does Not Determine When Tires Are Removed From Service." May 23, 2006.
  • Rubber Manufacturers Association. "Tire Maintenance and Safety." (10/15/2009)
  • Tire Industry Association. "Passenger Tire Replacement." 2009. (10/15/2009)
  • Welsh, Jonathan. "What's Inflating Your Car's Tires." Oct. 7, 2009. (10/15/2009)