The heat generation index refers to the ability of a tire to resist heat generation when tested under standard conditions on experimental wheels in a designated laboratory. Continuous high temperatures can cause aging, thereby shortening the service life of tires, while excessively high temperatures can lead to tire blowouts. Therefore, the US Department of Transportation (DOT) stipulates that all tires must meet the minimum heat generation level of "C" - the speed requirement of 136 km/h specified in US Federal Motor Vehicle Safety Standard 109. B "and" A "grades indicate that the tire exceeds the minimum performance specified by DOT, with" A "grade being the best.
