2009 Audi S4 Wheel Fitment Guide

This page compiles the known factory wheel and tire specs for the 2009 Audi S4 and explains how to use the on-page calculator to check interchangeability and custom sizes safely. If a value is not listed here or varies by trim, confirm it with your VIN using OEM sources and the calculator before purchasing.

Known OEM Fitment Specs

Notes:

• Bolt pattern 5x112 means 5 wheel bolts on a 112 mm circle.
• Audi typically uses wheel bolts rather than nuts. The thread size above is the bolt spec. Always match the bolt seat type to the wheel design. If seat type is not known, check the wheel manufacturer documentation or your OEM parts catalog.
• If your trim has larger brakes or a special package, confirm spoke and barrel clearance with the calculator and a physical test fit.

How to Use the Wheel Interchange Calculator

The calculator lets you compare a donor wheel and tire to your 2009 Audi S4. It updates overall tire diameter as you change rim diameter, so you can visualize fit and speedometer impact.

Basic comparison

• Set “Installed on” to your vehicle and load the known OEM spec above if not prefilled.
• Enter the donor wheel and tire specs under “Wheels from.” If you do not know the donor offset or center bore, get them from the wheel maker or an OEM catalog for that donor vehicle.

Custom wheel and tire sizing

• Open “Custom wheel size” to adjust rim diameter, width, and offset. The tool will show inner clearance change and how far the wheel face moves outward.
• Open “Custom tire size” to change section width and aspect ratio. The calculator updates tire diameter automatically when you change rim diameter.
• Aim to keep overall tire diameter close to stock and ensure there is sufficient inner and outer clearance. Check both static and full-lock steering positions and suspension compression.

What to watch in the results

• Inner clearance to strut, spring perch, and liners.
• Outer “poke” relative to fender lips and arch liners.
• Brake caliper and spoke clearance. Barrel and spoke shapes vary by wheel design, so verify physically when possible.
• Speedometer change and ground clearance changes due to tire diameter differences.

Safety and Compatibility Checklist

• Center bore 66.6 mm. The wheel’s center bore must be equal to or larger than 66.6 mm. If larger, use quality hub-centric rings sized to your wheel’s bore down to 66.6 mm. Do not force a smaller bore onto the hub.
• Bolt pattern 5x112 only. Patterns like 5x114.3 will not fit safely.
• Thread size M14x1.5. Use correct-length, correct-seat bolts for the wheel design. If unknown, consult the wheel manufacturer.
• Load rating. Wheel and tire load ratings must meet or exceed the Audi S4 requirements for your market and trim. Confirm via OEM documentation or the tire and wheel technical sheets.
• TPMS. System type and sensor frequency can vary by market and build. Reuse compatible sensors or program new ones per OEM specs. If unsure, check your owner’s manual or dealer by VIN.
• Brakes. Some trims or markets may have different rotor and caliper sizes. Always verify spoke and barrel clearance with the calculator and a test fit.

Understanding Offset and Backspacing

Offset ET45 means the mounting pad is 45 mm toward the street side from the wheel centerline. Increasing offset moves the wheel inward. Decreasing offset moves it outward. Backspacing 5.77 in is the distance from the hub mounting pad to the inner wheel lip. Use the calculator to visualize how changing offset and width alters inner clearance and outer poke.

Popular Change Scenarios

Upsizing to 19 inch

You can evaluate 19 inch options by setting a 19 inch rim in the calculator, then choosing a tire size that keeps the overall diameter close to stock. Confirm inner clearance, fender clearance, and speedometer change. Check brake clearance on the actual wheel.

Wider wheels for more grip

Increasing width changes both inner and outer positions. Use the calculator to balance offset so the inner edge clears suspension while the outer edge remains within the fender. Then choose a tire width and aspect ratio that maintains adequate clearance and proper load index.

Install Tips

• Clean the hub face and center spigot. Remove rust and debris for proper seating.
• If using hub-centric rings, seat them fully on the hub or wheel per the ring design.
• Hand start bolts to avoid cross-threading. Tighten in a star pattern.
• Use the factory wheel bolt torque from your owner’s manual. If you do not have it, contact an Audi dealer with your VIN.
• Recheck bolt torque after initial driving on new wheels.

How to Confirm Any Missing Specs

• Use the calculator on this page to load your 2009 Audi S4 and compare candidate wheels and tires.
• Check your owner’s manual and the OEM parts catalog using your VIN for wheel, tire, TPMS, and brake details.
• Ask the wheel manufacturer for exact offset, width, center bore, and seat type for the specific part number you plan to buy.

Helpful Tools and Supplies

• 1/2 inch drive torque wrench
• Wheel hanger guide pin M14x1.5
• Digital caliper for measuring center bores and studs
• M14x1.5 wheel bolts, correct seat type for your wheel

Always verify tool and part compatibility with your exact wheel and vehicle configuration.

Summary

Your 2009 Audi S4 is known to use a 5x112 bolt pattern, 66.6 mm center bore, M14x1.5 wheel bolts, and commonly an 18x8 ET45 wheel with 235/40R18 tires. Before purchasing or installing different wheels or tires, use the calculator to compare dimensions, confirm brake and fender clearance, and verify any unknown values with OEM sources. Do not assume compatibility without measurements and documentation.