Tires may seem like a boring necessity that you need to keep your car, truck, or motorcycle on the road.  If you delve into automotive history, you'll find some interesting facts about those rubber wheels.

1. Early cars used “artillery wheels” that had the tire bolted to the wheel. Have fun changing that flat.
2. For the first 25 years of the car, all tires were white. Zinc oxide was added to the rubber for strength, but had a side effect of making bright white tires.
3. By the second decade of the 21^st Century, researchers were looking for more ways to increase durability. Carbon black, a waste product of the petroleum industry, added longevity to the tire, but changed the color to black.
4. Originally, the whitewall tire was invented when a carbon black tread was melded with a zinc white sidewall. The result was the world’s first whitewall tire, made by Vogue Tyres of Chicago, in 1914.
5. Whitewalls were originally on both sidewalls. The cars had open fenders, and pedestrians could see both sides of the tires as a car drove by.
6. Raised white letter tires are made in the same fashion as whitewalls. An extra step covers the sidewall with black, then grinds the rubber off the letters to let the white show through.
7. In 1961, Goodyear experimented with an illuminated tire. Lit from the inside by glass incandescent bulbs, the softly glowing white tires never left the show circuit.
8. Run-flat tires can temporarily drive without air, as the thicker sidewall supports the vehicle’s weight for up to 100 miles. Despite the performance disadvantages, BMW fits the most run-flats to their vehicles.
9. Over 250 million tires are discarded each year. Recent recycling programs melt the rubber for asphalt, or shred them for garden mulch. Some companies even make new tires out of old tires.
10. Most new cars do not come with spare tires. Manufacturers are desperate to shed weight, and sell new cars with a patch kit and can of compressed air.
11. The classic Mini Cooper rode on a 165 millimeter wide tire, on a 10 inch diameter wheel. The new Mini Cooper Clubman rides on a 225 millimeter tire, wrapped around an 18 inch wheel.
12. Speed ratings are set in kilometers per hour. This is why speed ratings are unusual mile per hour figures, like Q: 99 mph, or R: 106 mph.
13. The Space Shuttle’s main wheels are approximately the size of those found on an 18-wheeler. However, one Space Shuttle tire can support 142,000 pounds, and is rated for 259 mph.
14. Michelin is working on producing the “tweel”, a one-piece airless wheel and tire. The tweel offers the possibility of no flat tires, and replaceable treads.
15. The highest speed rating is Y, at 186 miles per hour. Z rated tires came out first, rated at 149+ mph, back when they thought no one would ever need a higher rated tire.
16. A Moto GP racing motorcycle has two tire contact patches (the part that is on the ground at any one time), each the size of a deck of cards. A Formula 1 racecar has four contact patches, each approximately the size of a sheet of 8.5” by 11” paper.
17. NHRA Top Fuel teams get only four to six runs out of their tires. That means fresh tires become worn out tires after only 2 miles of use.
18. Lego is the largest manufacturer of tires. The toy company produces 306 million of the little tires every year.