Audi Q3: Tires with emergency running characteristics, PAX

  Caution

It is mandatory for run-flat tires to have a tire pressure monitoring system in the vehicle.

Work on tires with emergency running characteristics (PAX) must only be performed at skilled facilities.

These have the corresponding trained personnel and necessary tools available.

PAX Tires, Construction

  Caution

It is mandatory for run-flat tires to have a tire pressure monitoring system in the vehicle.

PAX tires involve specially developed system that exhibits the following differences in comparison to conventional tires:

Pax tires with supporting ring

- -I- PAX tires with air

- -II- PAX tires without air

- The tire is anchored to a special rim that prevents it from sliding off when pressure is lost. The rubber supporting ring ensures stability in emergency operation.

• The inner and outer bead diameter are different sizes. This makes it possible to place the tire in a supporting ring.
• The tire is anchored to the rim differently.
• In this way, the tire height could be reduced considerably. That was possible because the area near the bead could be considerably smaller due to the special connection between the tire and rim.
• The tire bead is formed so that it can engage in the rim seat. Therefore, it remains firmly in the seat when pressure is lost.

Standard tire, beat area construction

1 - Rim flange

2 - Fabric shell

3 - Bead bundle

PAX tire, bead area construction

1 - Loop

2 - Fabric shell

3 - Bead bundle

4 - Rim flange

PAX tires, anchoring

The secure seating of the tire in the rim is ensured in all driving situations due to the type of construction.

A wedge-shaped component of the tire is pressed between the bead bundle and rim when loaded. This happens independently of the pressure in the tire.

PAX tires, dimensions

In contract to conventional tires, tires with emergency running characteristics (PAX) exhibit differences in regard to dimensions and designations.

Therefore, PAX tires can only be mounted on special rims (PAX).

1 - Width in mm: the tire width from flank to flank on standard rim (corresponds to width specification on standard tire)

2 - Outer circumference in mm: maximum diameter of a new tire

3 - Designated diameter in millimeters on standard rim seat

4 - Smaller bead diameter in millimeters: rim seat on outer side

5 - Larger bead diameter in millimeters: rim seat on inner side

PAX Tires, Designations

In contrast to conventional tires, other designations are found on the tire flanks of PAX tires. In this way, these tires can be allocated clearly.

PAX tires, designations

245 - Tire width in millimeters

690 - Outer diameter in millimeters

R - Radial construction

500 - Designated diameter on standard rim seat

A - Tire quality grading for PAX tires (A- "asymmetrical") because both rim seats have different diameters

99 - Indicator of maximum load permitted for this tire (99 = 1550 kg (3417 lb)

Y - Speed code letter ("Y") corresponds to a permitted maximum speed of 300 km/h (186 mph)

Support Ring on PAX Wheels

Dimensions

Overview of the most important dimensions:

Designations

Example: 90-500(35) CLI A 1 876107

  90 - Designated width in millimeters

 500 - Designated diameter in millimeters

  35 - Height in millimeters

 CLI - Support ring versions: CLI - Clip supporting ring/FL - standard supporting ring

  A - Build type index, asymmetrical. Indication of wheels with emergency running characteristics (PAX)

  1 - Supporting ring versions

876107 - CAI, international item code

Dimensions and Designations on PAX Rims

Example: 235 x 500 A - 5 - 41

235 - Designated width in millimeters

  x - One-part

500 - Designated diameter of standardized rim seat in millimeters

  A - Asymmetrical

  5 - Number of bolt holes

  41 - Offset in millimeters

Tire Inflation on PAX Wheels

When filling tires, pay special attention to the following points:

- After mounting the tires with inserted valve insert, fill with air. At 1 bar (14.5 psi), check whether both beads are seated correctly.

- If one of the beads is not seated correctly, do not deflate air from tire but rather position the assembly roller on the affected beat and press on by rotating slightly. The bead then seats itself.

- Then continue filling until the tire pressure recommended for the vehicle is reached. Tires can also be filled with tire filling gas as with conventional tires.

  Note

Do not briefly overinflate tires to 3.5 bar (50.76 psi) as is common with conventional tires.

Vehicle Alignment and Adjustment

The chassis adjustment is done on vehicle with tires with emergency running characteristics (PAX) in the same way as on vehicle that are equipped with conventional tires.

Generally, the same gauge heads and mounts that are suitable for conventional tires with a rim protection strip can be used for tires with emergency running characteristics (PAX). (Supports on inner side, mount in tire tread).

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