2009 Audi R8 4.2 FSI V8
The 2009 Audi R8 4.2 FSI V8 tire size and wheel specifications below reflect standard OEM reference fitment data for this trim level.
Detailed tire and wheel breakdown for the 2009 Audi R8
Tire geometry â 235/40R18
The 235/40R18 fitted to the 2009 Audi R8 has a section width of 235mm and an aspect ratio of 40%, mounted on a 18-inch rim. That gives a sidewall height of 94.0mm (3.70") and an overall outside diameter of 645.2mm (25.40"). At highway speed this tire completes roughly 493 revolutions per kilometre, which is what your speedometer and odometer are calibrated against.
Plus-sizing window
If you want to upsize wheels on the 2009 Audi R8 while keeping the speedometer accurate, target a 245/33R19 (plus-one). For a softer ride or winter setup, a 225/47R17 (minus-one) keeps the overall diameter within Âą3% of stock, which is the industry tolerance for ABS and stability control to stay calibrated.
Wheel fitment specs
The 2009 Audi R8 uses a 5x112 bolt pattern with a 57.1mm hub bore. Safe rim width range for the OEM tire is 8.0J â 9.0J, and offsets in the ET37 â ET47 window will clear suspension and fender without rubbing on most setups.
Staggered setup notes
The 2009 Audi R8 ships staggered: 235/40R18 up front and 285/35R18 on the rear. That is a 285mm vs 235mm width difference â do not rotate front-to-rear, and replace tires in axle pairs to keep ABS and traction control balanced.
Tire pressure guidance
Manufacturer-recommended cold tire pressure for the 2009 Audi R8 is printed on the driver-side door jamb sticker â always defer to that value, not to the maximum pressure printed on the tire sidewall. Check pressure monthly and before long trips; under-inflation by 20% can reduce tread life by 25%.
Fitment Specifications
| Engine & Trim | Tire Size | Rim Size | Offset (ET) |
|---|---|---|---|
| 4.2 FSI V8 | 235/40R18 Rear: 285/35R18 | 18" x 8.5 | ET42 |
Frequently Asked Questions
What tire size does the 2009 Audi R8 4.2 FSI V8 use?
The 2009 Audi R8 4.2 FSI V8 uses 235/40R18 tires as standard equipment.
What is the bolt pattern of the 2009 Audi R8 4.2 FSI V8?
The 2009 Audi R8 4.2 FSI V8 has a 5x112 bolt pattern with a center bore of 57.1mm.
What is the wheel offset of the 2009 Audi R8 4.2 FSI V8?
The 2009 Audi R8 4.2 FSI V8 has a wheel offset of ETET42.