The 2009 Audi A6 sits in the era when Audi’s midsize sedan blended understated executive styling with confident road manners and available larger-wheel sport presentations. For owners today, tire choice is less about vintage sizing conventions and more about matching the car’s exact wheel setup. This 2009 Audi A6 uses radial tires in either 245/40R18 or 245/45R17, depending on configuration. That opens up useful choice in blackwall performance-oriented tires, plus redline and raised white letter options for a more customized look. The key is confirming whether the car is on 17-inch or 18-inch wheels before comparing series, sidewall style, and intended use.
Which Tire Size Is Right for The 2009 Audi A6
Two tire sizes apply to the 2009 Audi A6, and the first thing to confirm is wheel diameter. The car uses either a 245/40R18 radial on an 18-inch rim or a 245/45R17 radial on a 17-inch rim. Since both sizes appear on the Audi A6 Base, the real decision starts with the wheels currently on the car, then moves to sidewall style, tire series, and how the car will be used.
A 245/40R18 tire uses a 245-millimeter section width, a 40-series aspect ratio, radial construction, and an 18-inch rim. On a 2009 Audi A6, this size suits cars running the larger wheel setup and keeps the fitment in a modern radial format. Available choices include blackwall performance and drag-oriented tires, along with Pro-Trac Street Pro III options in redline or raised white letter styling. This size is the right starting point when the car already has 18-inch wheels and the goal is to match that setup while comparing appearance and use-case differences.
A 245/45R17 tire carries the same 245-millimeter nominal width but uses a taller 45-series sidewall on a 17-inch rim. It is also a radial fitment, making it appropriate for 2009 Audi A6 configurations equipped with 17-inch wheels. Product choices include blackwall tires from brands such as BFGoodrich, Nitto, and M&H Racemaster, plus Pro-Trac Street Pro III options with redline or raised white letter treatment. This size should be evaluated when the car is running 17-inch wheels and the buyer wants to balance correct fitment with style and intended driving use.
Sub-model fitment is simple here in one sense and important in another. The 2009 Audi A6 Base can use both covered tire sizes, so identifying the wheel diameter on the car matters more than sorting through multiple trim-specific tire programs.
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2009 Audi A6 Base
The 2009 Audi A6 Base uses radial tires in either 245/40R18 or 245/45R17, depending on which wheel package is on the car. That makes wheel confirmation the first step, followed by choosing among available blackwall, redline, or raised white letter tire options in the correct size.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 2009 Audi A6 Tires for Sale
Available 2009 Audi A6 tire choices cover both 245/40R18 and 245/45R17 radial sizes, with offerings from BFGoodrich, Nitto, M&H Racemaster, and Pro-Trac. The product grid is most useful for comparing blackwall, redline, and raised white letter styles along with series such as g-Force, NT555 G2, Street Pro III, and Drag Radial.
These FAQs focus on the exact tire sizes used on the 2009 Audi A6, how 17-inch and 18-inch wheel fitment affects selection, and what to consider when comparing tire style, performance focus, and road-use readiness.
Tire Size & Fitment
What tire size fits a 2009 Audi A6?
The 2009 Audi A6 uses two radial tire sizes: 245/40R18 and 245/45R17. Both sizes appear on the Audi A6 Base, so the car is not limited to a single fitment across all covered configurations.
The deciding factor is the wheel diameter currently on the car. A 17-inch wheel takes 245/45R17, while an 18-inch wheel takes 245/40R18. Before choosing a tire, check the wheel size stamped on the rim or confirm the size printed on the existing tire, especially if the car has been changed from its earlier wheel setup.
What size rim does a 2009 Audi A6 use?
A 2009 Audi A6 can use either a 17-inch or 18-inch rim with the tire sizes covered here. The 245/45R17 tire is paired with a 17-inch rim, and the 245/40R18 tire is paired with an 18-inch rim.
Rim diameter needs to be confirmed before anything else because the two tire sizes are not intended for the same wheel. Once diameter is verified, compare the tire’s rim-width range against the wheel on the car and look at sidewall style, intended use, and any changes from aftermarket wheels or suspension modifications.
Why does the 2009 Audi A6 have more than one tire size?
The 2009 Audi A6 has more than one tire size because it could be equipped with different wheel diameters. That is why both 245/45R17 and 245/40R18 appear for the same model year and core model.
The two sizes are very close in overall diameter, but they are built for different rim diameters and should not be treated as interchangeable by default. For the buyer, that means the first job is verifying the actual wheels on the car now, not assuming every A6 from this year uses the same tire simply because the model name is the same.
Choosing the Right Tire
What should I consider when choosing a 245/40R18 tire for a 2009 Audi A6?
Start with the basics: the car must be on 18-inch wheels, and the tire should be the correct 245/40R18 size. From there, choices in this size include blackwall tires from M&H Racemaster, BFGoodrich, and Nitto, along with Pro-Trac Street Pro III options in redline and raised white letter form.
Selection comes down to how the Audi A6 is used and how you want it to look. Some tires in this size lean toward performance street driving, while the M&H option is drag race focused. It also helps to compare the wheel’s width with the tire’s approved rim-width range so the tire chosen matches the wheel as well as the intended character of the car.
What sidewall styles are available for 2009 Audi A6 tires?
The available sidewall styles for the 2009 Audi A6 sizes covered here are blackwall, redline, and RWL, which means raised white letter. Those styles appear across both 245/40R18 and 245/45R17 fitments.
Blackwall keeps the presentation closer to modern OEM-style appearance, while redline and raised white letter options create a more customized look. Sidewall style does not change the need to match the correct tire size to the wheel diameter, so appearance choices should come after confirming whether the car is on 17-inch or 18-inch wheels.
What brands offer tires for the 2009 Audi A6?
Tires for the 2009 Audi A6 in these sizes are available from M&H Racemaster, BFGoodrich, Nitto, and Pro-Trac. The lineup covers both 245/40R18 and 245/45R17 radial fitments.
Brand choice is only one part of the decision. It helps to compare tire series, sidewall treatment, rim-width compatibility, and the intended role of the tire, since the selection ranges from drag-oriented products to more conventional street-performance options. Matching the brand to the exact size and wheel setup matters more than picking by name alone.
Restoration & Appearance
Which tire should I choose for a period-style 2009 Audi A6?
A period-style 2009 Audi A6 usually starts with staying in the correct modern radial size for the wheel on the car, either 245/45R17 or 245/40R18. For a more understated original-era look, blackwall tires generally suit the A6’s executive-sedan character better than more overt sidewall treatments.
The next step is deciding how strictly the car’s appearance is being preserved. Redline or raised white letter options can create a custom presentation, but they shift the visual character away from a typical 2009 luxury-sport sedan look. Owners pursuing a highly faithful restoration should compare tire appearance with period photos, window-sticker documentation, or marque-specific reference material.
How does tire construction affect the appearance of a restored 2009 Audi A6?
For the 2009 Audi A6, tire construction is straightforward because the covered primary fitments are radial. That means the appearance question is less about bias-ply versus radial and more about profile, wheel diameter, and sidewall presentation within the correct radial size.
A blackwall radial usually keeps the car looking closest to its model-year character, especially on a clean factory-inspired restoration. Redline and raised white letter versions in the same size can still fit the visual goal for a custom build, but they make a noticeably stronger styling statement than a plain black sidewall.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2009 Audi A6?
Yes, modifications can affect tire fitment on a 2009 Audi A6 even when the tire size itself is correct. Aftermarket wheels, altered offsets, suspension lowering, brake changes, or fender work can all change how a 245/40R18 or 245/45R17 tire sits in the car.
That makes it important to inspect the actual setup rather than relying only on the model year. Check wheel diameter and width first, then look at inner clearance, outer fender clearance, and turning clearance at full steering lock. A tire that suits a stock-wheel A6 may need closer scrutiny on a car that has been visually or mechanically modified.
What should I inspect before driving a 2009 Audi A6 on new tires?
Before driving a 2009 Audi A6 on new tires, inspect the wheels for correct diameter and condition, confirm the tires are mounted in the proper size, and set inflation pressure for the car’s actual application. It also helps to verify that there is no rubbing at rest or during steering movement.
A short road test should be followed by another quick visual check. Look for uneven seating on the rim, signs of contact in the wheelwell, vibration, or air loss. On a car with 17-inch and 18-inch fitments both in circulation, that extra confirmation step is worthwhile because an incorrect assumption about wheel size can lead to the wrong tire being chosen.
What should I check before a longer drive in a 2009 Audi A6?
Before a longer drive in a 2009 Audi A6, confirm the tires are the correct size for the wheels, inspect tread and sidewalls for cuts, cracking, or bulges, and make sure inflation pressure is appropriate. Pay attention to any vibration, pull, or unusual noise during shorter local driving before setting off.
Longer trips put more heat and sustained load into the tire, so condition matters as much as fitment. It is smart to recheck pressure when the tires are cold, verify lug hardware is secure after recent wheel work, and inspect the spare or roadside equipment as well. Cars that sit for extended periods deserve especially careful pre-drive tire inspection.
