Evolution of Car Tires
Engines and body designs are some of the most visible signs of advances in automotive technologies, but the humble tires that connect your car with the road have gone through just as many changes over the years. The first car tires from the 1800s bear only a superficial similarity to today’s cutting-edge tires. We’ll trace the development of tire designs, from the original air-filled rubber tubes that replaced iron-clad wooden wheels to modern car tires.
1888: The First Pneumatic Tires
When Karl Benz invented the first gasoline-powered car in 1888, the engine wasn’t the only innovation; the car rested on the first pneumatic tires, constructed from metal, covered in rubber and filled with air. The concept of pneumatic tires was first thought up by Robert William Thomson in 1847, but his design never made it to production. Instead, it was John Boyd Dunlop who developed the first practical pneumatic tire; the first tires found their use on Dunlop’s son’s tricycle. These early tires were made possible by the vulcanization process invented by Charles Goodyear and Thomson, which gave rubber enough durability to survive road use.
At that time, the public was still used to wood and iron wheels, so they were excited by the prospect of a ride that wouldn’t send the shock of every bump and pothole running through the vehicle. The popularity of the pneumatic car tires increased after they were featured in the Paris-Bordeaux race of 1895. These first tires were tall and skinny, similar to today’s bicycle tires.
1905: Treaded Tires
As automobiles grew larger, heavier and more powerful, car tires needed to become stronger as well. In 1905, tire makers introduced the first treaded tires. These tires featured a durable, stiff tread on the outer edge of the tire; the tread absorbed the initial shocks and wear from the road, protecting the rest of the tire from road damage. With the tread taking the brunt of the abuse, treaded tires could be stronger and absorb shocks more easily.
1923: Balloon Tires
In 1923, Firestone introduced the balloon tire, a type of low-pressure tire that improved handling and performance. Because these tires used lower air pressures, more of the tire’s surface area was in contact with the road, allowing the tire to grip the road more firmly. These tires were used in mainstream automobiles for some time, but future developments pushed them out of mainstream use. However, balloon car tires are still popular with off-road vehicles and sand buggies; their unique characteristics help with the challenges of driving on sand and other unfavorable surfaces.
1931: Synthetic Rubber
By the 1920s, rubber car tires were a necessity for automobiles, but they relied upon expensive and limited quantities of natural rubber. Throughout the 1920s, the Bayer laboratories worked on producing a synthetic alternative. In 1931, the Du Pont Company successfully industrialized the production of synthetic rubber, increasing both the availability and the quality of tire rubber.
1946: Radial Tires
In 1946, Michelin introduced a tire technology that would soon become the industry standard: the radial tire. By arranging the individual cords of the tire at a 90 degree angle to the direction of travel, Michelin improved steering performance, increased the lifespan of the tread, and increased gas mileage by reducing the rolling resistance of the tires. Radial car tires made their debut on the 1948 Citröen 2CV, and the technology was quickly adopted throughout Europe and Asia. Adoption lagged behind in the United States because of the increased cost of radial tires, but a 1968 review in “Consumer Reports” finally convinced Americans to adopt radial tires. In 1970, Ford offered the first American vehicle with radial tires as standard equipment, the Lincoln Continental Mark III.
1947: Tubeless Tires
Early car tires were composed of two separate parts, a durable outer tire and an inner tube that actually held the air. If the inner tube developed a leak, the entire tire would immediately blow out; because of friction inside of the tire, inner tubes burst with some regularity. In 1947, B.F. Goodrich introduced the first tubeless tire. By reinforcing the outer walls of the tire, the company was able to eliminate the inner tube, storing the pressurized air directly within the tire walls. This improved reliability and tire life while also making the ride more comfortable. As part of the initial testing of these car tires, small groups of the taxis and police cruisers of Ohio used the tires; the feedback was so positive that all of the vehicles soon switched to the tubeless tires. After Goodrich won the patents for their tubeless tires, the design became standard in 1955.
Flat Tire? No problem! Run-flat Tires
As early as 1937, tire manufacturers have made a variety of different run-flat car tires, which allow for limited mobility in the event of a flat tire. There are three main varieties of run-flat tires:
- Self-supporting tires have reinforced internal construction that can support the weight of the vehicle without air for a brief period of time. The extra strength does add weight to the tire, but it allows the vehicle to make its way to a service station in the event of a blowout.
- Self-sealing tires include a liner that seals itself in the event of a small puncture, such as from a nail or screw. As long as the puncture isn’t too large, this lining quickly and permanently seals the puncture.
- Auxiliary-supported tires include a secondary support mechanism inside of the tire, typically a band around the wheel, which allows the vehicle to continue operating without air. These types of tires don’t offer a terribly comfortable ride in run-flat conditions, but they are durable and capable of supporting the vehicle at high speeds.
Run-flat tires do carry several drawbacks, but for certain segments of the transportation industry they’re absolutely indispensable. In 1994, the Chevrolet Corvette became one of the first vehicles to offer run-flat tires as a piece of standard equipment.
Ultra High Performance (UHP) Tires
Traditionally, the biggest and most powerful vehicles required special tires to handle the higher demands that such cars and their drivers placed on their tires. For many years, any tire with a “V” speed rating (rated for 149 mph and above) was considered a UHP tire. However, as vehicle performance has increased, the definition of UHP car tires has changed. Modern UHP tires go beyond speed rating and reflect factors such as improved handling or superior braking performance. UHP tires are available as standard equipment for many vehicles now, and they’re available as aftermarket purchases for almost all vehicles.
The Return of Airless Tires
Air-filled tires have been a mainstay of automotive technology for more than a hundred years. Recently, manufacturers have begun working on car tires that possess all of the desirable characteristics of air-filled tires without the drawbacks of relying on pressurized air. Michelin’s Tweel design replaces the air-filled bladder with high-strength polyurethane spokes; the outer rim of the Tweel remains a durable rubber tread. Bridgestone has introduced a similar concept, which they call the NPT. In both designs, the obvious benefits of not relying on pressurized air are also joined with superior braking performance and greater sustainability for the tire components. However, at high speeds they are prone to producing excessive vibration. Neither technology has seen wide adoption in cars yet, but Michelin’s Tweel has found some applications in military vehicles and heavy-duty construction vehicles.
Fun Tire Trivia
Some interesting tire tidbits:
- The fastest complete tire change, using only hand tools, was completed in 59.62 seconds.
- The most expensive car tires belong to the Bugatti Veyron. The complete set of Michelin PAX run-flat tires checks in at $26,000. The tires had to be custom designed to withstand the extreme performance of the Veyron, such as its 250 mph top speed. Each tire has to offer performance similar to racing car tires while lasting significantly longer than the 70 miles that an average racing tire will last.
- The most expensive tires, period, belong to the Airbus A380. Each of the jet’s tires clocks in at a cool $92,000.
Tires have changed to keep up with advances in automobiles, from simple air-filled tubes to cutting-edge performance tires. What do you think of the latest advances in airless tires?