What is the tire J value reference table?
2 Answers
Below is the tire J value reference table. Wheel width (J value) refers to the distance between the flanges on both sides of the wheel hub, which determines the tire width. 1. The "7.0" in the wheel hub refers to 7 inches, and "J" represents the shape and height of the wheel hub flange (there are also C, JJ, JK, K, etc., with C being the lowest and K being the highest). The wheel width determines the installable tire width. 2. In addition to J, there are also C, JJ, JK, K, etc., mainly differing in the height of the protrusion, with C being the lowest, K being the highest, and J being the most common wheel hub type.
The tire J-value chart is essentially a reference tool for rim width and tire compatibility. The J-value is the code for rim width, such as 5J, 6J, where the "J" represents the design standard for the rim edge. I frequently use this chart during routine vehicle maintenance because mismatched tire widths can lead to unstable driving or increased wear. Generally, the corresponding tire width ranges for common J-values are as follows: 5J is approximately 155-175mm wide, suitable for small cars; 5.5J is 165-185mm, ideal for compact cars; 6J covers 175-195mm, which most family cars use; 6.5J is 185-205mm, and 7J is 195-215mm wide, suitable for SUVs or modified vehicles. I always advise car owners to first check their vehicle manual or the original rim specifications rather than relying solely on the chart when purchasing tires, as improper sizing can lead to safety issues—especially at high speeds, where tires that are too narrow or too wide can significantly affect handling. It's best to measure and confirm at a professional shop before replacing tires.
