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P ASSENGER C AR T IERS. Prepared by : Majid Al Jabr Supervised by: Dr.Sadi Assaf. O UTLINE. INTRODUCTION VE Job PLAN Selection Investigation Evaluation Development Implementation Life Cycle NEW TECHNOLOGY CONCLUSION. I NTRODUCTION. I NRODUCTION. Air craft tires
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PASSENGER CAR TIERS Prepared by : Majid Al Jabr Supervised by: Dr.Sadi Assaf
OUTLINE • INTRODUCTION • VE Job PLAN • Selection • Investigation • Evaluation • Development • Implementation • Life Cycle • NEW TECHNOLOGY • CONCLUSION
INRODUCTION • Air craft tires • Truck tires • Passenger tires • Racing tires • Motor Cycles tiers
INRODUCTION • When do we need to Replace Tires? • Tires are typically replaced when their natural lifespan has come to an end. There are however any number of factors that can affect this including storage, temperature, surfaces they are driven on, how aggressive of a driver you are, punctures, etc. • The usual recommendation for replacing tires is when they no longer feel safe to the driver. You can see when they are legally worn out using the tread wear indicator. A typical set of tires under normal driving conditions will last approximately 40 000 miles or 64 000 km. Some tires of-course are designed for much longer, even up to 80 000 miles or 128 000 kilometers.
SELECTION • The process of selecting the right tires for your car is simply a matter of knowing where and how you're going to use those tires. • What is the weather usually like? • Are the roads in good condition? • How far do you drive on an average day? • Do you have a sports car or a station wagon? • Knowing the answers will steer you to the right tires.
TIRE TYPES • All-Season Tires: One of the most popular types of tires sold today, all-season radials, are designed to handle dry and wet surfaces, and some amounts of snow. • Performance Tires: These tires are designed to provide more grip. They let you "feel the road" and drive with confidence. The trade-off is that these tires are generally more expensive, their tread may wear down faster, and some ride comfort is sacrificed. But for enthusiast drivers, performance tires are the choice.
TIRE TYPES • All-Season Performance Tires: This new breed of tire combines the features of performance tires with the features of all season tires. It meets the needs of high performance cars in dry conditions, but also handles rain and light snow. • Snow Tires: These tires are specially constructed to grip snowy surfaces. Even the rubber is specially formulated to stay pliable in the cold and give you better traction on icy roads. However, this same construction makes snow tires prone to more rapid treadwear than other tires on dry surfaces.
PASSENGER TIRE SIZES • Most passenger vehicles come equipped with P-Metric and Euro-Metric tire sizes. It is important to understand these sizing systems in selecting the proper tire for your vehicles. • P Metric • With the P-Metric system, Section Width is measured in millimeters. To convert millimeters into inches, divide by 25.4. The Aspect Ratio (Section Height divided by Section Width) helps to provide more dimensional information about the tire size. • Aspect ratio is expressed as a percentage (75%, 70%, 60%) and is commonly referred to as the tire series (75, 70, 60 series). Lower aspect ratio tires tend to look shorter and wider.
TIRE SIZES P 205 / 65 R 15 89 H Speed Symbol Load Index Rim diameter in inches Radial Construction Aspect Ratio (Conversion: 7.28" X .70 = 5.10" Section Height) Section Width (mm) Conversion: 185 mm ÷25.4 = 7.28") Passenger Car
TIRE SIZES • Euro-Metric • This system originated in Europe and is also referred to as the European Metric System. Most European tire manufacturers build tires that conform to this system. • The Metric System is very similar to the P-Metric System, except in terms of load carrying capacity. Load carrying capacities of Metric and P-Metric tires are sometimes not the same, even for two tires of the same size designation. • Size dimensions of P-Metric and Metric tires are basically the same. It is important to note, however, that actual size dimensions can vary slightly from one manufacturer to another
INVESTIGATION • Gathering data • Function • Rim size 15” – 16” • Compare different types
DESCRIPTION Of TIRE DIMENSIONS • Static Loaded Radius: distance from the center of the axle to the ground under specified load and inflation pressure. • Rim Diameter: diameter of the rim from bead seat to bead seat. • Overall Diameter: diameter of the tire from tread surface to tread surface while inflated but unloaded. • Overall Section Width: distance between the outer sidewalls of an inflated tire. • Rim Width: distance between the inside of the rim flanges. • Section Height: distance from the bead seat to the outer tread surface of the inflated tire. • Section Width: distance between the outer sidewalls of an inflated tire, less any ornamentation or curb ribs. • Tread Width: the width of the tread surface, designed for contact with the road.
SERVICE DESCRIPTION • The service description provides two important facts about the tire. First, the number designation is it's load index. Second, the letter designation indicates the tire's speed rating. The rating will appear with the load index following the size designation in the Service Description. (NOTE: In the past, speed ratings appeared in the tire size before the construction designation, as in P185/70HR14 or 205/60VR15.)
Speed Ratings Many of today's automobiles come equipped with speed rated Original Equipment tires. Speed rating passenger tires originated in Europe, where highway speeds can exceed 100 mph(160kph). The speed rating indicates the maximum speed a properly inflated tire will withstand for a determined time. Testing for speed rating certification is conducted in a laboratory setting.
FUNCTION • Tires perform four important functionswith the assistance of the air contained within them: • Tires support the vehicle chassis off the ground. • They help absorb shocks from the road surface. • They help transmit traction and braking forces to the road surface. • Finally, they help change and maintain the direction of travel.
FUNCTION VerbNoun • support chassis • absorb shocks • transmit traction • change direction
EVALUATION CriteriaRaw ScoreAssigned Wt A Initial cost 5 10 B Performance 4 8 C Average Distance 3 6 D Speed Limit 1 2 How Important Scoring Matrix B C D 3. Major A A/B A-2 A-2 2. Medium B B/C B-2 1. Minor C C-2
EVALUATION MATRIX IC P AD SL IDEAS Assigned Value Total Wt 10 8 6 2 Present Idea 5 E E E E Rank 4 VG VG VG VG 3 G G G G 2 F F F F 1 P P P P ST 40 24 24 4 92 5 E E E E 4 VG VG VG VG 3 G G G G 2 F F F F 1 P P P P ST 50 32 24 8 114 5 E E E E 4 VG VG VG VG 3 G G G G 2 F F F F 1 P P P P ST 40 40 24 6 110 5 E E E E 4 VG VG VG VG 3 G G G G 2 F F F F 1 P P P P ST 30 40 24 8 102 4 1 2 3
How do I compare price vs. value? • Why is it that the price of fuel for our vehicle seems relatively inexpensive while the cost of its tires seems high? • (Of course we already know that The Tire Rack tries to keep our tire costs as low as possible!) If we keep track of our total costs we will find that typical total fuel costs for just 10 to 20 thousand miles of driving actually exceed our tire costs. And believe it, it had found that the quality and performance of our tires has a lot more to do with driving satisfaction than fuel does. • We think that much of the misperception has to do with the fact that we buy fuel one tank full at a time, and don't really look at its total cost for thousands of miles. Our tires are paid for "up front" and then last for tens of thousands of miles. • When you are selecting new tires and find one that is perfect, although more expensive than another tire that appears to be a close second; consider evaluating your situation by comparing "how much per mile" each tire will cost. If you plan to drive your vehicle another 30,000 miles and are considering the "perfect" tires at $100 each, and the other at $90 each; you may be surprised to find out that the cost of the "perfect" set costs just 1.3¢ per mile...while the close set costs 1.2¢ per mile. Will saving the $40 today make up for not having selected the "perfect" tire that you will be driving on for the next two years?
LIFE CYCLE • When outdoor temperature changes occur, your tire's inflation pressure is affected. For every 10 degree (Fahrenheit) drop in temperature, tire pressure will drop one pound per square inch. In hot weather, tires can lose up to two pounds of air per month. Underinflation is the leading cause of tire failures so check inflation pressure regularly.
MAINTENANCE • Valves New valve stem, core and cap are recommended for all new tubeless tires. • Lubricant Tire beads and rim flanges should be treated with a recommended lubricant inside and out. Beads should be lubricated both during mounting and dismounting (in case you wish to remount the tire and also to protect the wheel from damage). • Do not, under any circumstances, use liquids such as oil, gasoline, spirits, or water.
MAINTENANCE • Tire rotation is vital to achieving even tread wear and long tread life. Rotation is necessary because of the uneven wear characteristics of each wheel position on the vehicle. A good example is Front Wheel Drive vehicles which places braking, steering and driving forces on the front axle tires. Rear axle tires only receive braking forces resulting in a much faster wear rate for the front axle tires. Tire rotation for these vehicles therefore becomes very important for optimum tire life.
MAINTENANCE • The "Cross Pattern" provides the best results and can be performed on any Front or Rear Wheel Drive vehicle.
MAINTENANCE • 5 Tire Rotation • If the vehicle owner has a regular tire as a spare tire and wishes to include it in the tire rotation process, the proper procedure is to use the appropriate rotation pattern shown for 4 Tire Rotation, BUT insert the spare in the right rear position. Place the tire which would have gone to the right rear in the trunk as the new spare. • Note: Never include a temporary spare tire in the rotation.
CONCLOSUION • The selection of tire depend on several factors. • All tires achieve optimum life if maintenance done periodically.
SPEED SYMBOL *Current tire speed rating markings include the use of the service description to identify the tire's speed capability (P215/65R15 95V -maximum speed 149 mph). Previous customs included the speed symbol in the size designation only(P215/65VR15) and the speed capability was listed as "above 130 mph(240kph)." **Any tire with a speed capability above 149 mph(240(kph) can, at the tire manufacturer's option, include a "ZR" in the size designation (P275/40ZR17). If a service description IS NOT included with the size description, the tire manufacturer must be consulted for the maximum speed capability (P275/40ZR17--speed capability is >149mph). If a service description is included with the size description, the speed capability is limited by the speed symbol in the service description (P275/40ZR17 93W = maximum speed 168 mph(270kph).)
