Every tire you see has numbers and letters on the sidewall. What most people don’t know is that these numbers reveal information about the size, model and brand of the tire. As such, the U.S. Department of Transportation requires all tires to have these markings as standard.
The first letter usually means the class of the tire. For instance, the letter P means the tire is meant for passenger cars. There are instances where the letters LT appear before these markings. In this case, these letters mean the tire is meant for light trucks.