What is the explanation of tire specification parameters?

[LeMiranda]

The explanation of tire specification parameters is: The international standard tire code, expressed in millimeters for the section width and the percentage of the aspect ratio, followed by the tire type code, rim diameter (in inches), load index (allowable load mass code), and allowable vehicle speed code. Taking 215/70R15 as an example: The meanings of 215/70R15 are respectively: 215 represents the tire section width, the unit is mm, with an interval of 10mm; 70 is the aspect ratio, which is the ratio of the tire sidewall height to the tire section width, 70 represents 70%, generally the aspect ratio of tires ranges from 30% to 80%. Under normal circumstances, ordinary cars should not use tires with an aspect ratio greater than 75%, while luxury cars and high-performance sports cars are recommended to use tires with an aspect ratio less than 60%; R is the abbreviation of Radial, indicating that the tire has a radial structure, and 15 is the outer diameter of the rim, the unit is inches.

[DiLondon]

Tire specifications are actually quite important. After driving for so many years, I've accumulated some experience. For example, take 205/55R16 91V: 205 indicates the tire width is 205 millimeters—the larger the number, the wider the tire, which provides better stability at high speeds; 55 is the aspect ratio, meaning the tire height is 55% of the width—a higher percentage offers a more comfortable ride; R stands for radial construction, which most cars use nowadays; 16 is the rim diameter in inches, which must match the wheel hub; 91 is the load index, equivalent to a carrying capacity of 615 kilograms; and V is the speed rating, with a maximum of 240 km/h. Choosing the wrong size, like a slightly smaller rim diameter, can cause the tire to rub against the body, leading to a bumpy ride and potentially affecting the braking system. I think checking the manual or the label on the door frame is the most reliable way to avoid safety hazards. Always inspect the wear condition before replacing tires. Don’t compromise on the wrong specs to save money—once, I rushed into replacing tires with the wrong size, and it caused a sharp increase in fuel consumption and noticeable steering wheel vibrations. I had to visit a professional shop to fix it before I could drive normally again. In short, don’t overlook these small parameters—they directly impact driving safety.

[DelBrielle]

As a car owner, I take tire parameters seriously. Take 225/60R17 103H for example: the 225mm width affects grip and gives an advantage when off-roading; the 60 aspect ratio provides better shock absorption on bumpy roads; R stands for radial tire standard; the 17-inch rim diameter must match the vehicle model; the 103 load index can bear 875kg; and the H speed rating has a maximum of 210km/h. Wrong parameters make driving uncomfortable—for instance, too low an aspect ratio makes tires stiff, causing backaches on city roads. I’ve also found that insufficient load index increases the risk of blowouts when fully loaded due to low tire pressure. Last year during a trip, the tire pressure monitor suddenly alarmed, and the mechanic said the tire size didn’t match the factory recommendation—only after switching to the correct specs did it feel stable. Now during every service, I check the parameter label to ensure consistency. It’s not just a habit but also a matter of safety.

[EdenFitz]

I often help friends choose tires, so I need to understand the specifications. Take 195/65R15 92T for example: 195mm width ensures agile handling; 65 aspect ratio is moderate; R stands for radial construction; 15-inch rim matches the size; 92 load index equals 630kg capacity; T speed rating means 180km/h max. Simply put: width in millimeters affects stability, aspect ratio percentage impacts comfort, rim inches must be precise, load index numbers correspond to weight capacity via chart, and speed rating letters indicate speed limits. Mistakes can be costly—like incorrect sizing throwing off the odometer. Once, I replaced rear tires with larger rims, only to hear terrifying scraping noises against the fenders during turns, forcing me to revert to original specs. Always check the manual first—don’t experiment blindly.