Share This Article


This article is from our archives and has not been updated and integrated with our "new" site yet... Even so, it's still awesome - so keep reading!

Published on Sun, Feb 17, 2008

By: The LACar Editorial Staff

THE RUBBER MEETS THE ROAD By Reed Berry, "The Traffic Guy" If you were asked to list the most important safety systems on your vehicle, you may think of the cup holder that prevents a steaming latte from spilling on your Hugo Boss slacks, or even the GPS navigation system that helps you reach your destination without going through "bad" neighborhoods. In my opinion, however, one of the most important - and certainly one of the most technically sophisticated - systems on any automobile is the set of tires on which you ride. Consider the fact that your tires are the only part of the vehicle to make contact with the road. That alone should make you realize the importance of buying good quality tires and maintaining them properly. In addition, the tires you select will be a primary factory in your vehicle's performance and comfort. And while all tires may be round in shape, they are definitely not the same. Never buy a set of tires just because they look "cool" or because you saw tires at a bargain price in a newspaper ad. Less expensive tires may appear to help you save money, but a cheap tire isn't necessarily a good value. You should select tires based on your driving style, the amount of driving you do, and the weather conditions in which you normally drive. And never buy only one tire. Tires should be purchased in pairs or a set of four. Placing a new tire on the same axle with a worn tire can affect your vehicle's overall performance.

It's All In The Numbers There's no guesswork involved in obtaining important details about the tires on your vehicle as there is unique identifying information embedded on the sidewalls. But what do all those letters and numbers mean, you ask. If your tire reads P185/70R14 87S for example, it tells you the following:

  • "P" stands for P-Metric. This is one of the two most commonly used systems to identify passenger tire sizes. The other is European-Metric, commonly called Euro-Metric.
  • "185" is the tire's section width in millimeters. This is the distance from the edge of the sidewall to the edge of the opposite sidewall when the tire is mounted and properly inflated.
  • "70" designates aspect ratio. Also called the profile or series, this is the ratio of the tire's section height to section width. This tells you that this 70 series tire is 70 percent as tall as it is wide.
  • "R" refers to radial - the tire's type of construction. Radial construction has dominated the American marketplace since the 1970s, when rising gas prices triggered consumer demand for radial tires.
  • "14" is the rim diameter in inches. It tells you the tire must be mounted to a 14-inch wheel. But be aware that not every 14-inch tire fits every 14-inch rim. The width of the rim is also important.
  • "87" is the load index. When referenced with the tire's specified maximum inflation pressure, such as 35 psi, the load index indicates the maximum weight in pounds the tire is designed to support at that pressure. For example, this tire will carry 1,201 pounds at 35 psi.
  • "S" is the speed rating. This is an alphabetical system describing a tire's capability to travel at established and predetermined speeds - allowing vehicle owners to compare the performance capabilities of different tires.

Frequently Asked Questions (and Bridgestone Firestone Answers) When you want answers to tire questions, why not go to straight to a respected source of information. Founded in 1931, Bridgestone is known for quality tires and is clearly the choice for many of the world's most prestigious automobile brands. Before running out to purchase the next set of tires for your vehicle, consider the following information provided by Mike Filipek, OE Account Manager, Sales Engineering, Bridgestone Firestone North American Tire. LA Car: How do I know which tire is right for my vehicle? Filipek: Tire manufacturers suggest choosing the original equipment (OE) tire with which your vehicle is fitted from the manufacturer to optimize performance and to maintain the feel for which your vehicle was designed. Normally a vehicle manufacturer works in concert with the tire company to design a tire suitable for a specific vehicle application to optimize the vehicle handling. In some circumstances a customer may desire different performance characteristics from the OE tire, perhaps one with better grip, wet handling or that handles on unique surfaces (snow, off-road). It is wise to consult your local tire retailer for suggestions. LA Car: As long as I pick the right size, will any type of tire work? Filipek: Typically the tire and vehicle are designed by the automotive manufacturer as a package. Depending on the consumer's preference and driving styles, many tires may fit the vehicle, but some may be more suitable than others for the specific application. Distinct designs, tread patterns and compounds all offer unique performance characteristics in tires and some may be of greater significance to the end user. Some of these characteristics include mileage, performance, handling, wet traction, etc. Tires are designed for specific uses. A reputable tire retailer can offer insight into the best tire fitment for your vehicle based on your driving habits. For example, if an individual lives in a snowy climate, choosing a winter tire would be more sensible than choosing an all season tire. LA Car: What is the best way to maintain my tires for maximum life? Filipek: Checking the air pressure each month is advised since tires can lose 1 psi (pound per square inch) monthly. Additionally, tire pressure can drop 1 psi for every 10 degrees F drop in temperature. Compound this loss over time and your vehicle may be riding on a very under inflated tire. Tire rotation and balancing can improve the life and performance of your tires and are important factors as well. For maximum mileage, rotate your tires every 5,000 miles. LA Car: How often should I check the inflation of my tires? Filipek: You should check your air pressure at least once a month, and before taking a trip (don't forget the spare). For accuracy, check your air pressure with a tire gauge when tires are cold (vehicle has been parked for three or more hours or driven less than one mile). Driving heats up tires and increases tire pressure readings. The proper inflation pressure for your vehicle is listed in the owner's manual of your vehicle or the door jamb. Some vehicles may recommend different inflation front and rear. The tire sidewall lists MAXIMUM inflation pressure and should not be used as an inflation guide. LA Car: What should I look for to determine if its time for new tires? Filipek: Always check for obvious signs of wear: exposed tread bars, shoulder wear, center wear and irregular shoulder wear or cracking. You can also perform the Lincoln Penny test. Place a penny in the tire's tread (with Lincoln's head facing down), if you can see the top of Lincoln's head, the treads are worn and need replacing. LA Car: How can I tell if my tires are over inflated or under inflated? Filipek: Start by checking inflation pressure with a tire gauge. The proper inflation pressure can be found on the vehicle door jamb or in your owner's manual. Never use the number on the sidewall of your tire - this is the maximum pressure. Not only should you test the pressure with a tire gauge, but you should frequently perform visual inspections of your tires. If your tire is under inflated, the shoulders of the tire will be more worn. If the tire is over inflated, the center begins to wear more quickly.

Product Review: Bridgestone Turanza EL400 All-Season Tires As someone who has driven in California for over thirty years, I am well aware that the claims a tire company makes about their products may differ slightly - or even greatly - from a tire's actual road performance. A good set of tires, in my opinion, must provide exceptional handling in a variety of driving conditions as well as a comfortable ride. Combine these characteristics with good looks and you have Bridgestone Turanza EL400 all-season tires. When it comes to automobile tires, one must sometimes make certain sacrifices. If you want tires that deliver superior handling and performance, you may find yourself settling for a ride that is less than comfortable and even a bit noisy. And if you buy tires for a smooth, comfortable ride, you may sacrifice performance. Bridgestone seems to have found the proper balance in this tire. I am impressed by both the performance and comfort. I can definitely feel the road, yet the ride is smooth and fairly quiet. A noise reduction system incorporated into the tires produces noise canceling soundwaves to reduce tire noise. As a hard rain begins to fall, I can't help but notice that the tires are as confident on wet roads as they are on dry surfaces. Bridgestone claims that this is due to a specially formulated compound designed to improve traction on wet surfaces and because of a "rounder" tire shape. are round, aren't they? Can something actually be rounder than round? Hey, I'll believe anything. As a safety expert, I have a healthy respect for any company that places a high degree of importance on safety. The innovative construction and unique tread design have created a quality tire that seems to live up to the company's claims and gives me a feeling of security as I drive. Bridgestone Turanza EL400 all-season tires appear to provide exceptional performance at an affordable price. For information on Bridgestone Tires: For tire safety information:

You Might Also Like These Articles:

image of Tesla factory

Top 4 Car Recalls in 2024

image of a person working on a car at a mechanic shop

The Risks to Your Tires When Shipping a Car

two cars on a road

Breaking Down the Statistics

the inside of an engine

Horsepower Meets Actual Horses

vintage car parked with the sundown in the background.

Vintage Cars, High Stakes