To refrain from blowouts.
Rubber
Aircraft tires are the same materials that auto tires are, just with a different tread pattern.
The same materials summer tires are made of. They just have a different tread pattern.
Rubber
The comparison of wholesale tires to premium tires is that premium tires are more costly, but are also made to last longer due to better manufacturing materials used to ensure driver safety.
I have found that Michelin and Bridgestone tires are the most expensive of the tires that they sell at my local dealership.
http://www.epa.gov/osw/conserve/materials/tires/faq.htm try googling next time....
From the research that I have done I have found that the Mastercraft brand of tires is a good tire brand. I have found that they sell a very wide range and selection of tires to suit your needs.
Plies are the construction materials use to make a tire. The body ply is a sheet consisting of one layer of rubber, one layer of reinforcing fabric, and a second layer of rubber. The earliest textile used was cotton; later materials include rayon, nylon, polyester, and kevlar. Passenger tires typically have one or two body plies. They can also be reinforced with steel. Body plies give the tire structure strength. Truck tires, off-road tires, and aircraft tires have progressively more plies. The fabric cords are highly flexible but relatively inelastic.
I have found that Sam's Club and Costco have the lowest prices on new tires. They also will replace the tires for you right at both stores. I have found them to be very quick as well.
Radial ply tires and tubeless tires are made from rubber, fabric, and steel.
Yes, tires are covered in the Toyota extended warranty, as tires are very important in a vehicle and can go wrong at any time. It is necessary to have such materials covered in warranties.