Load Index and Speed Rating?
2 Answers
1. Meaning of Load Index: The numerical value indicating the maximum load that a tire can bear under specified conditions when inflated to its maximum air pressure. It is usually represented by a number. If the total weight of the vehicle exceeds this value, the tire deformation will be significant, leading to increased heat generation during prolonged operation, ultimately causing tire fatigue damage, reduced lifespan, and even structural failure resulting in a blowout accident. 2. Meaning of Speed Rating: It is denoted by a letter, ranging from J to Z. Under the corresponding load capacity of the relevant load index, each letter represents the maximum permissible speed of the tire.
I found that the load index indicates the maximum weight a tire can bear, while the speed rating represents its allowed top speed. For example, if your tire sidewall has markings like 91H, the 91 is the load index, meaning each tire can carry about 615 kilograms; the H stands for 210 km/h. These details really can't be ignored. Last time I drove my family on a trip, we overloaded the tires with too much luggage, nearly causing a problem on the highway—luckily, I checked the specifications and matched the original factory requirements. When changing tires, I always advise friends to first check their car's manual. Choosing the wrong grade can lead to rapid wear or even blowouts, which is not only dangerous but also costly. At high speeds, the speed rating also affects stability; switching to a lower-grade tire can make the car feel unstable and scary at high speeds. In short, these specifications are designed to ensure your driving safety. Taking a moment to understand them before choosing tires can save a lot of trouble.
