Tires are mostly made of what?
AnswerRubber
Natural and synthetic rubber are the main ingredients.
Vehicles · Facts & stats
Tire facts & stats
7 fact-checked facts about tires, treads and tire care, each with the reason behind it. 5 more are in today's round and join this page after it closes.
The basics
In the US penny test, the penny goes in the tread with whose head pointing down?
AnswerAbraham Lincoln
If you see all of Lincoln's head, the tread may be too worn.
Going deeper
Charles Goodyear is known for developing which process for rubber?
AnswerVulcanization
Vulcanization with sulfur makes rubber durable.
Where is a car's recommended tire pressure usually listed?
AnswerOn a sticker in the driver's door jamb
The sidewall number is the tire's maximum, not the target.
Why are tires rotated between positions?
AnswerTo help them wear evenly
Front and rear tires wear at different rates.
Expert level
What additive makes most tires black and more durable?
AnswerCarbon black
Carbon black strengthens rubber and resists UV damage.
In a tire size like 205/55R16, what does the 55 mean?
AnswerSidewall height as a percentage of tire width
It is the aspect ratio; 16 is the wheel diameter.
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