How Tires Work
Anaheim Hills Tire & Automotive Center

Goodyears' successful tire introductions in recent years can be credited in part ot developing our products from the "market back". This is done by talking directly to consumers and determining what kinds of features and benefits they desire from their tires. So Goodyear responded with the new introduction of Assurance®, Wrangler®, Fortera®, and the new Eagle® Featuring ResponseEdge Technology™. Goodyear Eagle® featuring ResponseEdge Technology™ has precise handling and luxury performance with a carbon fiber reinforced sidewall. This tire is for high-performance touring drivers who desire crisp maneuverability and handling without sacrificing a smooth, quick ride. The outer sidewall is reinforced with carbon fiber cords that help stiffen the sidewall and help deliver a better feel for the road, while an Insulayer made with DuPont KEVLAR® helps absorb road noise and vibration. Technology Brand Benefit Assurance® Passenger Tires Assurance® featuring TripleTred Technology Assurance® featuring ComforTred Technology® Superb traction in any weather condition- wet, snow and dry Smooth and luxurious ride Wrangler Truck Tires Wrangler® featuring SilentArmor Technology™ Rugged toughness and a quiet, comfortable ride Fortera SUV Tries Fortera® featuring SilentArmor Technology™ Fortera® featuring TripleTred Technology™ Rugged toughness and a quiet, comfortable ride Superb traction in any weather condition- wet, snow and dry Eagle® Performance Tires Eagle® featuring ResponsEdge Technology™ Helps provide crisp, responsive handling with a smooth, quiet ride   TESTING RESULTS Eagle® featuring ResponsEdge Technology™ vs   Michelin Energy™ MXZV4 Plus® Michelin Pilot® HXMXM4 Plus™ Bridgestone Turanza® LSH™ Cooper Lifeliner touring SLE H Wet Handling Test Outperforms Comparable Comparable Significantly Outperforms Dry Handling Test Significantly Outperforms Comparable Significantly Outperforms Outperforms Ride Test - Broken Concrete @ 40 MPH Comparable Outperforms Comparable Comparable Interior Noise Test - Smooth Road @ 50 MPH Significantly Outperforms Comparable Comparable Comparable Wet Stopping Test - ABS On Comparable Comparable Comparable Significantly Outperforms Goodyear/Industry 100 FT. Slalom Test Significantly Outperforms Outperforms Significantly Outperforms Significantly Outperforms Goodyear Emergency Lane Change Test Outperforms Significantly Outperforms Outperforms Outperforms   If you're in the market for new tires, all of the variables in tire specifications and the confusing jargon you might hear from tire salesmen or "experts" might make your purchase rather difficult. Or maybe you just want to fully understand the tires you already have, the concepts at work, the significance of all of those sidewall markings. What does all this stuff mean in regular terms? On this page, we will explore how tires are built and see what's in a tire. We'll find out what all the numbers and markings on the sidewall of a tire mean, and we'll decipher some of that tire jargon. By the end of this article, you'll understand how a tire supports your car, and you'll know why heat can build up in your tires, especially if the pressure is low. You'll also be able to adjust your tire pressure correctly and diagnose some common tire problems! How Tires are Made As illustrated below, a tire is made up of several different components. The Bead Bundle The bead is a loop of high-strength steel cable coated with rubber. It gives the tire the strength it needs to stay seated on the wheel rim and to handle the forces applied by tire mounting machines when the tires are installed on rims. The Body The body is made up of several layers of different fabrics, called plies. The most common ply fabric is polyester cord. The cords in a radial tire run perpendicular to the tread. Some older tires used diagonal bias tires, tires in which the fabric ran at an angle to the tread. The plies are coated with rubber to help them bond with the other components and to seal in the air. A tire's strength is often described by the number of plies it has. Most car tires have two body plies. By comparison, large commercial jetliners often have tires with 30 or more plies. The Belts In steel-belted radial tires, belts made from steel are used to reinforce the area under the tread. These belts provide puncture resistance and help the tire stay flat so that it makes the best contact with the road. Cap Plies Some tires have cap plies, an extra layer or two of polyester fabric to help hold everything in place. These cap plies are not found on all tires; they are mostly used on tires with higher speed ratings to help all the components stay in place at high speeds. The Sidewall The sidewall provides lateral stability for the tire, protects the body plies and helps keep the air from escaping. It may contain additional components to help increase the lateral stability. The Tread The tread is made from a mixture of many different kinds of natural and synthetic rubbers. The tread and the sidewalls are extruded and cut to length. The tread is just smooth rubber at this point; it does not have the tread patterns that give the tire traction. Assembly All of these components are assembled in the tire-building machine. This machine ensures that all of the components are in the correct location and then forms the tire into a shape and size fairly close to its finished dimensions. At this point the tire has all of its pieces, but it's not held together very tightly, and it doesn't have any markings or tread patterns. This is called a green tire. The next step is to run the tire into a curing machine, which functions something like a waffle iron, molding in all of the markings and traction patterns. The heat also bonds all of the tire's components together. This is called vulcanizing. After a few finishing and inspection procedures, the tire is finished. What All the Numbers Mean Each section of small print on a tire's sidewall means something: How To Read A Sidewall: P-Metric (example 1) P215/65R15 95S P = Passenger Car 215 = Section width measured in millimeters (25.4 millimetes per inch) 65 = Aspect Ratio, which means the sidewall height is 65 percent of the section width. R = Radial Carcass Construction 15 = Rim Diameter 95 = Load Index S = Speed Rating - View Speed Rating Chart Below A. Passenger car tire. B. Width of tire diameter. C. Ratio of height to width. D. Radial. E. Diameter of wheel in inches. F. Load index & speed symbol G. U.S. DOT safety standard code. H. Max. cold inflation & load limit. I. Treadwear, traction and temperature grades. J. Tire ply composition and materials used. Speed Rating Chart: Speed Symbol A7 A8 B C D E F G J Speed (km/h) 35 40 50 60 65 70 80 90 100 Speed (mph) 22 25 31 37 40 43 50 56 62 Speed Symbol R S T U H V W Y ZR* Speed (km/h) 170 180 190 200 210 240 270 300 Open Ended Speed (mph) 106 112 118 124 130 149 168 186 Open Ended * Contact Les Schwab Tire Centers for top speed capability. Traction There are a lot of different terms used today in the tire industry. Some of them actually mean something and some do not. In this section, we'll try to explain what some of the terms mean. All-Season Tires with Mud and Snow Designation If a tire has MS, M+S, M/S or M&S on it, then it meets the Rubber Manufacturers Association (RMA) guidelines for a mud and snow tire. For a tire to receive the Mud and Snow designation, it must meet these geometric requirements (taken from the bulletin "RMA Snow Tire Definitions for Passenger and Light Truck (LT) Tires"): 1. New tire treads shall have multiple pockets or slots in at least one tread edge that meet the following dimensional requirements based on mold dimensions: a. Extend toward the tread center at least 1/2 inch from the footprint edge, measured perpendicularly to the tread centerline. b. A minimum cross-sectional width of 1/16 inch. c. Edges of pockets or slots at angles between 35 and 90 degrees from the direction of travel. 2. The new tire tread contact surface void area will be a minimum of 25 percent based on mold dimensions. The rough translation of this specification is that the tire must have a row of fairly big grooves that start at the edge of the tread and extend toward the center of the tire. Also, at least 25 percent of the surface area must be grooves. Severe winter traction icon The idea is to give the tread pattern enough void space so that it can bite through the snow and get traction. However, as you can see from the specification, there is no testing involved. To address this shortcoming, the Rubber Manufacturers Association and the tire industry have agreed on a standard that does involve testing. The designation is called Severe Snow Use and has a specific icon (see image at right), which goes next to the M/S designation. In order to meet this standard, tires must be tested using an American Society for Testing and Materials (ASTM) testing procedure described in "RMA Definition for Passenger and Light Truck Tires for use in Severe Snow Conditions": Tires designed for use in severe snow conditions are recognized by manufacturers to attain a traction index equal to or greater than 110 compared to the ASTM E-1136 Standard Reference Test Tire when using the ASTM F-1805 snow traction test with equivalent percentage loads. These tires, in addition to meeting the geometrical requirements for an M/S designation, are tested on snow using a standardized test procedure.They have to do better than the standard reference tire in order to meet the requirements for Severe Snow Use. Hydroplaning A tire designed to help prevent hydroplaning Hydroplaning can occur when the car drives through puddles of standing water. If the water cannot squirt out from under the tire quickly enough, the tire will lift off the ground and be supported by only the water. Because the affected tire will have almost no traction, cars can easily go out of control when hydroplaning. Some tires are designed to help reduce the possibility of hydroplaning. These tires have deep grooves running in the same direction as the tread, giving the water an extra channel to escape from under the tire. How Tires Support a Car You may have wondered how a car tire with 30 pounds per square inch (psi) of pressure can support a car. This is an interesting question, and it is related to several other issues, such as how much force it takes to push a tire down the road and why tires get hot when you drive (and how this can lead to problems). The next time you get in your car, take a close look at the tires. You will notice that they are not really round. There is a flat spot on the bottom where the tire meets the road. This flat spot is called the contact patch, as illustrated below. A tire showing the side and bottom of the contact patch If you were looking up at a car through a glass road, you could measure the size of the contact patch. You could also make a pretty good estimate of the weight of your car, if you measured the area of the contact patches of each tire, added them together and then multiplied the sum by the tire pressure. Since there is a certain amount of pressure per square inch in the tire, say 30 psi, then you need quite a few square inches of contact patch to carry the weight of the car. If you add more weight or decrease the pressure, then you need even more square inches of contact patch, so the flat spot gets bigger. A properly inflated tire and an underinflated or overloaded tire You can see that the underinflated/overloaded tire is less round than the properly inflated, properly loaded tire. When the tire is spinning, the contact patch must move around the tire to stay in contact with the road. At the spot where the tire meets the road, the rubber is bent out. It takes force to bend that tire, and the more it has to bend, the more force it takes. The tire is not perfectly elastic, so when it returns to its original shape, it does not return all of the force that it took to bend it. Some of that force is converted to heat in the tire by the friction and work of bending all of the rubber and steel in the tire. Since an underinflated or overloaded tire needs to bend more, it takes more force to push it down the road, so it generates more heat. Tire Problems Underinflation can cause tires to wear more on the outside than the inside. It also causes reduced fuel efficiency and increased heat buildup in the tires. It is important to check the tire pressure with a gauge at least once a month. The wear patterns of an underinflated, properly inflated and overinflated tire Overinflation causes tires to wear more in the center of the tread. The tire pressure should never exceed the maximum that is listed on the side of the tire. Car manufacturers often suggest a lower pressure than the maximum because the tires will give a softer ride. But running the tires at a higher pressure will improve mileage. Misalignment of the wheels causes either the inside or the outside to wear unevenly, or to have a rough, slightly torn appearance.

Anaheim Hills Tire & Automotive Center Phone: 714-777-1711 19721 Esperanza Rd. Yorba Linda, CA. 92886 (1 Block East of Imperial Hwy.)