New Testing Conducted at Treadwell Research Park Reveals Driving on Worn Tires in Wet Conditions Can Worsen Stopping Distance by a Staggering 140 Feet

Simulating heavy rainfall on roads, worn tires needed as much as 90% more stopping distance

PHOENIX, June 25, 2026 /PRNewswire/ -- New testing conducted at Treadwell Research Park, a 900-acre research and testing facility owned by retailer Discount Tire, shows how detrimental driving on worn tires in wet conditions can be to stopping a vehicle. In conditions simulating roads that experienced recent light rain, worn tires required 30%-45% more stopping distance — equating to 44-67 additional feet, depending on the tire model — to bring a car to a full stop when braking. Decreases in stopping performance of worn tires compared to new tires of the same model were more dramatic in testing conditions simulating recent moderate and heavy rain on roads, requiring more than 140 feet of additional stopping distance in some tests.

"The differences we observed in stopping distance nearly doubling with an additional 140 feet needed, and even an additional 40 feet needed in conditions of light rain on the roads, can be the difference between safely braking your vehicle or not," said Josh Sortor, product and quality director for Discount Tire. "If you live in an area experiencing seasonal storms or heavy rain, this latest data from Treadwell Research Park shows your tires' tread is the true difference-maker in the safety of your tires."

May and June are the rainiest months in the U.S. on average, according to historical data from the National Climatic Data Center. Discount Tire's tire recommendation tool, Treadwell, allows drivers to view stopping distance performance data on hundreds of popular tire models, including comparing the stopping distance on wet roads between a new and a worn tire of the same model.

Any person researching or shopping for new tires can use Treadwell to compare the performance of multiple tire models and get a personalized tire recommendation based on where they drive, what vehicle they drive, and how they prefer to drive.

"At Discount Tire, we continuously evaluate tire performance through rigorous research, including independent wet-new and wet-worn testing conducted at Treadwell Research Park. These insights enhance our understanding of real-world tire performance and support our commitment to customer safety," said Tom Williams, chief experience officer at Discount Tire. "By translating complex research into clear, actionable information, Treadwell empowers drivers to make confident, informed tire decisions—delivering both peace of mind and greater trust in one of the most important safety investments they make."

Tests used Toyota Camrys outfitted with popular tire models from multiple tire manufacturers to simulate the performance of an everyday sedan. Water levels were controlled using Treadwell Research Park's advanced wet braking lanes, flooded to a consistent water height in simulation of light, moderate, or heavy recent rain, resulting in wet road conditions. Worn tires were professionally buffed to 4/32 of an inch of tread. Discount Tire recommends replacing tires worn below 4/32-inch tread depth.

Discount Tire developed Treadwell using decades of data and results of independent testing conducted at sites including Treadwell Research Park to deliver a hassle-free tool giving drivers personalized tire recommendations. Actual results may vary for an individual based on their specific driving location. More than 20 million people used Treadwell online and in-store last year.

How Treadwell Research Park Data Was Collected 

Discount Tire commissioned Smithers, an independent third party, to conduct variable water depth stopping-distance testing at Treadwell Research Park using multiple new and worn tire models. Each test consisted of an anti-lock braking system stop performed from 60 miles per hour. During each test, the stopping distance required by the vehicle to go from 60 to 0 miles per hour was measured in feet.

Tests used controlled water depths to simulate wet road conditions, ranging from light rain or mist, which is when the Federal Highway Administration observes 77% of weather-related crashes occur, to highways with standard drainage experiencing a recent period of heavy rain. Water depth on roadways is impacted by rainfall intensity, pavement slope and drainage, and surface texture.

A brand-new set of each tire model was installed on the test vehicles to collect the new tire wet stopping-distance data. An additional set of brand-new tires of each tire model was professionally buffed to approximately 4/32-inch tread depth and installed on the test vehicles to collect the worn tire wet stopping-distance data.

ABOUT DISCOUNT TIRE
Discount Tire is a leading independent retailer of tires, wheels, and windshield wipers. Founded in 1960 by Bruce T. Halle, the company serves customers at more than 1,275 stores in 40 states. The company does business as Discount Tire in most of the U.S. and as America's Tire in parts of California, Pennsylvania, New Jersey, and New York. Treadwell, the company's proprietary online tire recommendation tool, uses decades of data and individual driving habits to recommend the right tires for each driver's unique needs. Discount Tire is a primary sponsor of the No. 2 Ford Mustang in the NASCAR Cup Series and the Official Tire Retailer of Major League Soccer. For more information, visit www.discounttire.com.

Media Contact
Kerry O'Malley Gleim
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SOURCE Discount Tire