The alphanumeric markings found on a tire’s sidewall provide critical information regarding its specifications. An “H” or “T” designation, when appearing within the tire’s speed rating, indicates the maximum speed at which the tire can operate safely under optimal conditions. An “H” speed rating signifies that the tire is designed for a maximum speed of 130 mph, while a “T” speed rating denotes a maximum speed of 118 mph. These ratings are determined through standardized laboratory testing.
Understanding these speed ratings is crucial for selecting appropriate tires for a vehicle and driving style. Exceeding the tire’s maximum speed rating can lead to tire failure, compromising vehicle control and potentially causing an accident. Historically, tire speed ratings have evolved alongside advancements in vehicle performance, ensuring that tires can safely handle the increasing speeds of modern automobiles. Correctly matching the tire speed rating to the vehicle’s capabilities enhances safety and optimizes performance.