Table of contents: Wheel bolts and rims are a system ↓ Rims for winter tires ↓
An important measurement value of the rim is the pressing depth "d". It denotes the distance between the center of the rim and the adjacent surface on the wheel hub.
This is what a steel rim for an Audi A4 looks like. You will find the following information stamped into the metal
- 1 - rim designation;
- 2 - pressing depth;
- 3 - part number.
Genuine Audi wheel bolts for steel and light metal rims can be identified by the notches on the bolt head.
The Audi A4 can be equipped with rims with the following designations: 6 J X 15 ET 45 or 7 J X 15 ET 45. Sometimes the rim also has the additional designation "H2". The numbers and letters mean the following:
- 6 or 7: The width of the rim in inches, measured across the base of the rim flange across the direction of travel of the wheel.
- J: designation of the height of the rim flange.
- X: rim recess depth.
- 15: The rim diameter in inches, measured from bead to bead of the tire.
- ET 45: pressing depth 45 mm.
- H2: Double hump rim designation. Two bulges inside the rim bed prevent the tire beads from sliding off the rim flange under lateral load (sharp turn at low air pressure).
Wheel bolts and rims are a system
Wheel bolts and rims are a structural unit and therefore cannot be separated. The conical socket in the rim mounting holes exactly matches the cone of the wheel bolt. Other cone shapes cannot guarantee a secure fit of the bolt and therefore the fastening of the wheel. For rims (steel and light metal), factory-fitted bolts on the Audi A4 are only suitable for so-called crown-head bolts (part no. 431 601 139 A). These can be identified by the notches on the top of the bolt head.
Rims for winter tires
Winter tires should be purchased with the corresponding steel rims. At first glance, this is more expensive, but on the other hand, it eliminates the need for regular wheel rotation and balancing. Tire shops often offer sets at a reasonable price. For winter tires, they offer standard rims 6 J x 15. Or used rims are purchased.
Rims made of light metals can corrode to a state unsafe for road traffic when exposed to salts. Therefore, damage to the varnish covering the rim must be repaired as soon as possible.