2008 Audi R8 Wheel Fitment and Interchange Guide | wheelinterchange.com

Goal

You want to know if a wheel and tire set will safely fit a 2008 Audi R8 without rubbing, vibration, or hardware issues. The main risks are brake clearance, incorrect offset, hub mismatch, and tire diameter changes that affect handling and speedometer. We will use the on-page calculator to model changes, then validate on the car.

Prerequisites

• Confirm your vehicle’s exact trim and any factory options. Check the driver door placard and the owner’s manual.
• Gather the donor wheel and tire specs: diameter, width, offset, bolt pattern, center bore, and tire size.
• Have measuring tools and safe lifting gear ready.

• 1/2 inch drive torque wrench
• Digital caliper
• 57.1 hub-centric rings if your aftermarket wheels have a larger bore
• M14x1.5 wheel bolts if you need longer hardware for spacers

Safety first. Support the car on stands, not a jack. Wear eye protection and torque wheels only on the ground.

Known OEM fitment for 2008 Audi R8

Use these values as a baseline. If your car differs by trim or package, confirm with the door placard, the owner’s manual, or Audi service information.

Note a potential mismatch: the listed wheel is 19x8.5 ET42, while the listed tire size implies an 18 inch rim. Factory setups can vary by trim and axle. Do not assume. Validate your exact factory size on the door placard and with the on-page calculator.

Step by step

1) Set your baseline in the calculator

In the “Installed on (your vehicle)” side, select 2008 Audi R8. Enter the known OEM wheel values above. If your placard shows different sizes, use those instead. This gives you the reference for inner and outer clearance, scrub position, and rolling diameter.

2) Enter the donor wheel and tire

In the “Wheels from (donor vehicle)” side, enter the donor specs. If you only know diameter, width, and offset, start there. Add tire size when available. The calculator will show how far the inner barrel moves toward the suspension and how far the outer edge pokes toward the fender.

3) Adjust custom wheel size to manage offset and width

• Width change rule of thumb: each 0.5 inch of wheel width equals about 6.35 mm. Half the added width goes inward and half outward if offset is unchanged.
• To keep inner clearance similar, increase offset as width increases, or reduce offset as width decreases. The calculator applies this visually, so iterate until inner clearance stays acceptable.
• Watch outer poke. Keep fender and liner clearance with suspension loaded and during steering.

4) Set custom tire size and check diameter

• Changing rim diameter updates tire diameter in the comparison. Keep overall tire diameter near stock to maintain gearing and speedometer. A common workshop threshold is around 2 percent change, but confirm what you are comfortable with.
• Match tire load index and speed rating to or above the OEM values on the placard.

5) Confirm hardware and hub fit

• Center bore: the R8 hub is 57.1 mm. Larger-bore wheels need 57.1 hub-centric rings. Smaller-bore wheels will not fit.
• Fasteners: thread size is M14x1.5. Verify fastener seat type on your wheels. Audi applications often use a specific seat profile, but it can vary by wheel. Do not mix seat types.
• If using spacers, use hub-centric spacers and lengthened hardware. Validate thread engagement. Many technicians look for about 7 to 8 full turns minimum on M14, but confirm per your hardware supplier’s guidance.

6) Brake and suspension clearance

• Use the calculator to estimate inner barrel movement. Then measure on the car. You want clearance to calipers, knuckle, and control arms under full lock and compression.
• Spoke-to-caliper shape varies by wheel design. Do a physical test fit before mounting tires if possible.

Validation

• Clearances: with wheels installed, check inner barrel, spokes, and outer fender with the car on the ground. Turn lock-to-lock. Compress the suspension if practical.
• Runout and seating: ensure the wheel seats fully on the hub. No gap between wheel and hub face.
• Torque: tighten in a star pattern with a calibrated torque wrench. Use the torque specification from the owner’s manual or Audi service information. Re-torque after 50 to 100 miles.
• Road test: listen for rubbing. Verify straight-line stability and no vibration from 50 to 70 mph.
• Speedometer check: compare GPS speed to the cluster. The calculator estimate should be close if diameter stayed near stock.

Troubleshooting

• Vibration above 50 mph: check hub-centric rings, wheel balance, and that the wheel is truly hub-centric. Re-seat and re-torque.
• Rubbing on lock or bumps: reduce width, increase positive offset slightly, or select a narrower tire. The calculator helps you test these trade-offs.
• Wheel will not seat: confirm center bore is at least 57.1 mm and remove any hub corrosion. Lightly clean the hub face and pilot lip.
• Insufficient thread engagement: measure engagement depth. Use appropriate length fasteners when spacers are installed. Match seat type exactly.
• Brake caliper contact: choose a wheel with more spoke clearance or add a small hub-centric spacer with proper hardware. Validate again in the calculator and on the car.
• Tire warning or TPMS issues: sensor type and programming can vary. Refer to the owner’s manual or Audi service information for the correct procedure.

Wrap up

The calculator lets you compare donor wheels against your 2008 Audi R8 with clear visibility into offset, width, and tire diameter trade-offs. Start from the known OEM baseline, validate against your placard, and model changes until inner and outer clearances look safe. Confirm hub fit, fastener spec, and brake clearance with a careful test fit. With methodical checks and proper hardware, your new setup will drive straight, run quiet, and clear everything under real road conditions.