The dimensional relationship between tire section height and section width. If tire aspect ratio or tire sizing changes from what was found on the OE tires, the recommended inflation pressure may also change. If this occurs, the new recommended inflation pressure should be recorded on the tire placard in the doorjamb and, if possible, updated in the vehicle TPMS system software, to maintain a proper low-pressure warning threshold. Be sure to only use approved tires for your vehicle and verify all safety parameters with any non-OE tires.
Aspect ratio
