History
Believe it or not, the tire was invented approximately in the 9th century by Celtic tribes in western Europe. The tires were made of iron bands placed around wooden wheels while still red hot from the forge. They were quenched once on the wheel to make them contract into the rim of the wheel. The iron band prevented damage to the wheel, and allowed the wheel to be re-tread over and over making the wheels last longer. Eventually, Roman engineers copied the tire and spread it across the world. There are, however, other ancient examples of tires such as leather, hemp cordage, and bronze being used throughout the classical era.
The word tire is simply the shortened word "attire" meaning a dressing on the wheel. The earliest mention of the word "tyre" (from middle English) was in the 14th century when wheel dressings were applied to carriages in order to protect the wheel just as they had in the 9th century. The tire did not change until the mid 19th century, when rubber was first used as tires on carriage wheels.
In 1888, John Dunlop of Belfast, Ireland filed a patent for the pneumatic bicycle tire. He invented the pneumatic tire because his son would get headaches riding his bicycle with solid rubber tires. Dunlop realized that the cushion of air in a tube inside the rubber tire would provide a more comfortable ride. In 1895 Frenchmen Andre and Edouard Michelin developed and applied the first pneumatic tire at the Paris-Bordeaux road race. Their car did not win the race, but they did generate huge interest in their pneumatic automobile tire which government officials in Europe realized was safer and caused less damage to roads, prompting western governments to first regulate tires for automobile use. In 1898 Frank Sieberling started the Goodyear Tire and Rubber Company (named for George Goodyear, whom discovered vulcanized rubber) followed by Harvey Firestone founding the Firestone Tire and Rubber Company in 1900.
The first automobile tires were made with a rubber inner tube which held compressed air and an outer rubber casing that protected the inner tube and provided traction. The outer casing of the tire had fabric cords made of hemp or cotton known as plys. These tires were known as bias ply tires as the cord plys ran in an alternating pattern at acute angles from inner to outer bead (the part of the tire that seats against the wheel rim). In 1948 Michelin introduced the steel-belted radial tires marking the first major improvement to tire design in nearly 50 years. Radial tires' were so named for the pattern of the ply cords radiatating at 90 degree angles from the wheel rim across the tire. Radial tires' plys were then made from synthetic materials such as nylon improving tire durability and lateral strength. These tires also were the first to use a belt of steel wire wrapped around the circumference of the tire. Steel-belted radial tires had longer tread life, better handling, and improved fuel economy, however, they had a stiffer, less comfortable ride and were more expensive.
Steel-belted radial tires quickly became the standard tire of vehicles manufactured worldwide, except in the U.S. The American public was resistant to more expensive, hard-riding tires and American manufacturers saw them as a novelty and continued to produce bias-ply tires. By the mid 60s American automotive manufacturing was falling behind the rest of the world in innovation and development. In 1967 Goodyear improved upon the bias-ply design by adding a fiberglass mesh belt thus improving durability of the tire while maintaining low production costs, but did not improve safety or handling characteristics. Goodyear's improved bias-ply tires became the American standard tire and by the early 70's 87 percent of new American cars featured these tires.
The 1973 gasoline crisis spurned Americans to demand more economical vehicles. Imports of European and especially Japanese automobiles skyrocketed, and, of course, those vehicles were delivered with standard installed steel-belted radial tires. Over the course of 25 years foreign auto manufacturers had overcome the problem with harder ride by developing improved vehicle suspension systems and components while American made vehicles lagged behind. Import vehicles began to rapidly overtake market share from domestic manufacturers. In the mid 70's Firestone attempted to introduce it's own radial tire which ended up being a spectacular failure that destroyed the company resulting in its purchase by Bridgestone Tire of Japan. It wouldn't be until 1977 that Goodyear managed to deliver a tire competitive with foreign tire companies, and by 1983 all American vehicles would have radials standard, but only after import vehicles had secured approximately 30% of market share.
Essentially, modern tires, are the same as Michelin's first radial tire made in 1948. Modern radial tires contain plys and cords of stronger and more durable synthetic fibers even including Kevlar. Modern steel is stronger and can be manufactured for optimum performance in the tire then in previous decades. The biggest improvement in modern tires is the development of chemical elastomers added in the rubber manufacturing process which improve durability, tire grip characteristics, safety, fuel economy, and reduced damage to road surfaces.
Types of Tires
There are many different types of tires. For the purposes of this blog, we will focus on tires for standard consumer vehicles and exclude those for tractors and other heavy equipment. Consumer tires are divided into a few categories: passenger, light truck and SUV, and specialty. Those categories are then divided into sub-sections and are listed as follows below.
-Passenger-
All-Season: All-season tires are designed for maximum comfort on the highway as well as all-season traction and usually have a symmetrical tread pattern with several circumferential grooves for optimal traction in wet conditions. These tires will also have moderate siping (small etched patterns in the road or ground contact blocks).
Touring: Touring tires won't provide as much comfort and traction in wet weather as all-season tires and are designed for better handling capabilities in higher performance vehicles. These tires usually have non-symmetrical tread patterns with little siping but still have hydro grooves running the circumference of the tire.
Performance: Performance tires are designed with higher speed ratings then other passenger tires. They typically have larger tread grooves with little to no siping both lateral and circumferential to maximize grip in all conditions, and they have additives in the rubber compound that also improve grip. These tires are designed for high performance vehicles and will have stiffer ride compared to other passenger street tires.
Summer: Summer tires are optimized for driving on warm and wet road surfaces as they have a larger surface area of the tire without grooves and no siping at all for greater contact on the road. Summer tires can come in several speed ratings, but they are usually designed for higher performance vehicles.
Track: Track tires are designed to provide maximum grip and road contact in dry conditions. Track tires are made of higher quality materials including Kevlar for delivering the highest performance under extreme driving conditions. They are D.O.T. approved but are not ideal for road driving. They will have little to no tread grooves and likely will have no circumferential hydro grooves. Track tires with no tread at all are known as "slicks".
-Light Truck-
Highway: Highway truck tires are similar to all-season passenger car tires in that they provide maximum comfort and durability for daily driving in all conditions. They will typically have symmetrical tread patterns with moderate siping and several circumferential hydro grooves.
Ribbed: Ribbed tires are designed for maximum highway durability and safety. Ribbed tires are named for the uniform symmetrical tread pattern. Ribbed tires are designed for safety and comfort under heavy loads and are most often seen on commercial vehicles such as utility vans and cargo trucks.
Sport Truck: Sport truck tires are similar to passenger car touring tires. They typically have non-symmetrical tread pattern with lots of siping and higher speed ratings than highway tires. Sport tires will have a stiffer ride than other truck tire types and often have a shorter length sidewall similar to low-profile tires on a passenger tire as they are designed for better performance handling of the vehicle.
All-Purpose/Trail: All-purpose or trail tires are slightly more aggressively tread with little siping then highway tires for light off-road use, and they also feature hydro grooves for safety and stability on wet road conditions.
All-Terrain: AT truck tires are optimized for off-road use but are also designed for road use as well. They have fairly aggressive tread patterns without hydro grooves for dirt, gravel, and sand but still provide stability and comfort on paved roads. These tires usually have a severe weather symbol embossed in the tire sidewall.
Mud-Terrain: Mud tires feature very aggressive, deep tread patterns with large ground contact blocks. Mud tires are optimized for very loose off-road driving conditions such as soft sand and mud. They have reinforced sidewalls to resist punctures and damage from extreme off-road conditions. While D.O.T. approved for road driving, they are far less comfortable and noisy then all-terrain tires and will drastically affect vehicle fuel economy.
-Specialty Tires-
Winter: Winter tires are made for both passenger vehicles and light trucks. They feature symmetrical tread patterns with lots of siping in the road contact blocks but will have larger lateral and circumferential grooves for pushing snow, ice, and water away from the tire surface to optimize grip in poor road conditions. Winter tires can also be studded with small metal studs or pins to deliver maximum grip and stability in icy conditions, however, studded tires are illegal for road use in many states. There are also all-weather winter tires available for most vehicles that are optimized for temperatures below 45 degrees Fahrenheit and are less aggressively tread than snow and ice tires. All-weather tires are not well suited for extreme winter weather or warmer, fair weather.
Temporary Spare: Temporary spare tires or "donuts" as they are often referred to are general use road tires. They are designed to be used only temporarily until a full size standard tire can be repaired or replaced and refitted. These tires are much smaller and are only rated for 45-50mph and require higher air pressure than standard tires.
Run-Flat: Run-Flat tires are designed to keep the vehicle on the road even in the event of a puncture. Run-flats come in three different construction types; self-sealing, self-supporting, and auxiliary supported. Self-sealing tires have a special lining inside the tire that when punctured re-seals the puncture even around the object responsible for the puncture if still present. Self sealing tires may still slowly leak but may go a very long time before requiring replacement depending on the damage to the tire. Self-supporting tires feature a stiffer construction technique that allow the vehicle to continue driving in the event of air loss, however, they are only designed to support the vehicle temporarily (usually approximately 50 miles) until the tire can be replaced. Self-supporting tires can not be repaired and must be replaced as the tire structure will rapidly degrade when in run-flat condition. Auxiliary supported run-flat tire systems are highly specialized tire and wheel combinations. A specialized wheel is required to attach to a tire with a support structure inside the tire. In the event of air pressure loss the the tread of the tire rests on the internal support structure placing the weight of the vehicle on the wheel rather than the tire itself. This type of run-flat system is very expensive and usually only installed on high-end luxury vehicles.
Reading and Understanding Tire Sidewalls
All tires sold worldwide are embossed with vital information for the consumer and is uniform across all types and manufacturers of road vehicle tires. Listed below is a brief explanation to understanding that information. Shown are pictures of the tire sidewall in two sections and are listed as read from left to right.
Tire Specifications
1. Tire Type: Indicates type of tire, "P" passenger, "LT" light truck, "T" temporary, "ST" special trailer. If no letter is listed then the tire is a European metric passenger tire.
2. Tire Width: Indicates the width of the tire from outer to inner sidewall in millimeters.
3. Aspect Ratio: Indicates the aspect ratio of sidewall height to tire width. The lower the ratio, the lower the sidewall height. Lower sidewall height provides better handling in cornering but has a stiffer ride. Low aspect ratio tires are often referred to as low-profile.
4. Construction: Indicates tire construction type, "R" radial, "D" diagonal, "B" belted or bias-ply
5. Wheel Diameter: Indicates wheel diameter in inches.
6. Load Index: Indicates the maximum load on the tire corresponding to the Tire Load Index Chart (not as weight per tire).
7. Speed Rating: Indicates the speed rating of the tire "A" being the lowest to "Y" the highest. However there is an exception, "H" is actually between "U" and "V".
UTQG Code (Uniform Tire Quality Grading)
1. Department of Transportation stamp.
2. Tire manufacturer and production plant code.
3. Refers to tire size.
4. Optional code that refers to brand and other tire characteristics.
5. Week of the year tire was produced.
6. Year the tire was produced.
The history of tires goes way back in human history but their purpose remains the same. Tires are designed to get you where you need to go safely and to prevent damage to your vehicle and the roads. For whatever vehicle moves you, Full Blown carries all brands, types, and sizes of tires. Stay safe under any driving conditions and in any vehicle, and bring your vehicle to Full Blown Advanced Automotive Repair Center to get your next set of tires installed by our tire experts...For everything that moves you...