2018 Audi A6 Quattro Tires

The 2018 Audi A6 Quattro uses three radial tire sizes: 245/45R18, 255/40R19, and 255/35R20. Each size matches a different wheel diameter, so the correct choice depends on whether the car has 18-inch, 19-inch, or 20-inch wheels. Most covered sub-models use all three sizes, while Sport 2.0 and Sport 3.0 use the 19-inch and 20-inch fitments.

Start by reading the tire sidewall already on the car or confirming the wheel diameter directly. That matters more than trim name alone, especially on a later-model sedan that may have had wheels changed. Once the wheel size is verified, the next step is comparing tire series, sidewall style, and rim-width compatibility within that exact size.

A 2018 Audi A6 Quattro can use 18-inch, 19-inch, or 20-inch rims, depending on which tire size is on the car. The 245/45R18 fits an 18-inch rim, the 255/40R19 fits a 19-inch rim, and the 255/35R20 fits a 20-inch rim. All of these are radial fitments for this model range.

Wheel diameter should be confirmed before looking at tread pattern, brand, or sidewall treatment because an 18-inch tire cannot be mounted on a 19-inch or 20-inch wheel. It is also smart to check actual wheel width if the car has aftermarket wheels, since product options within the same size can carry specific rim-width recommendations.

Not every 2018 Audi A6 Quattro sub-model uses the exact same range of tire sizes. Premium 2.0, Premium 3.0, Premium Plus 2.0, Premium Plus 3.0, and Prestige all use 245/45R18, 255/40R19, and 255/35R20. Sport 2.0 and Sport 3.0 use the 255/40R19 and 255/35R20 fitments, but not the 245/45R18 size.

That means sub-model identification helps, but wheel diameter still tells the clearest fitment story. A car may also be wearing a different factory wheel package or a later wheel change, so checking the tire sidewall and the wheel itself is the safest way to narrow the correct size before comparing available tires.

Begin with the correct tire size for the wheel already on the car: 245/45R18, 255/40R19, or 255/35R20. From there, compare the available radial tire series, brand options, sidewall presentation, and any relevant rim-width guidance. On this Audi, the main choice is not bias-ply versus radial, but which modern radial best matches the car’s wheel package and intended look.

A buyer who wants a conventional appearance may stay with a Blackwall tire, while someone aiming for a more customized presentation may look at RWL or Redline options in the 19-inch or 20-inch sizes. It also helps to consider load figures where shown, tire weight, and whether the car is used mainly for daily road driving or more spirited seasonal use.

Sidewall choices for the 2018 Audi A6 Quattro include Blackwall, RWL, and Redline, depending on the tire size. The 245/45R18 options shown here are Blackwall only, while the 255/40R19 and 255/35R20 sizes add Pro-Trac Street Pro III choices with RWL or Redline sidewalls alongside Blackwall performance radials from BFGoodrich and Nitto.

That gives the car owner a meaningful appearance decision even when the size is already fixed by the wheel diameter. Blackwall keeps a more understated modern look, while raised white letter and Redline treatments create a more customized visual statement. The right choice depends on the car’s overall presentation rather than any automatic fitment advantage.

Tires for the 2018 Audi A6 Quattro are available here from BFGoodrich, Nitto, and Pro-Trac. BFGoodrich appears across all three sizes with g-Force and Phenom T/A series, Nitto is offered in NT555 G2 for selected sizes, and Pro-Trac appears in the 19-inch and 20-inch fitments with Street Pro III options in specialty sidewall styles.

Brand choice should still come after confirming the correct size and wheel diameter. Once that is settled, the comparison becomes more useful because the differences are easier to see in terms of series, sidewall style, and rim-width specifications. That approach keeps the decision focused on the tire that matches the car, not just the brand name.

A period-style approach on a 2018 Audi A6 Quattro usually means staying with the wheel diameter and tire proportions that suit the car’s original late-model executive-sedan character. That points first to the correct radial size already on the car, then to a sidewall treatment that matches the desired presentation. Blackwall options keep the most restrained modern look across all three available sizes.

For a more individualized appearance, the 19-inch and 20-inch sizes also offer RWL and Redline choices that change the visual tone without changing the basic size category. Because appearance preferences on modern collector cars can vary widely, it helps to consider the wheel design, ride height, and overall build theme before choosing a sidewall style.

On a 2018 Audi A6 Quattro, tire construction does not create a bias-ply-versus-radial appearance choice because the fitments here are all radial. The visual difference comes more from the size and sidewall treatment than from the construction itself. An 18-inch Blackwall setup presents differently than a 19-inch or 20-inch package with RWL or Redline sidewalls.

That makes wheel diameter and sidewall styling the main appearance tools when refining the car’s look. Keeping the tire matched to the wheel size already on the car preserves proper mounting, while the sidewall choice shapes whether the finished presentation feels understated, performance-oriented, or more customized. Those details tend to matter more than construction on this particular Audi.

Yes, modifications can affect tire fitment on a 2018 Audi A6 Quattro even when the tire size itself is one of the sizes used on this model. Aftermarket wheels, changes in wheel width, altered offset, lowered suspension, or body modifications can all change how an 18-inch, 19-inch, or 20-inch tire sits in the wheel opening and under steering movement.

A car with non-original wheels should be checked for actual rim diameter and width before a tire is selected. It is also wise to inspect fender and suspension clearance at full steering lock and under compression. That extra verification matters most with the wider 255-section sizes, where a wheel change can affect fitment even when the sidewall size looks familiar.

Before driving a 2018 Audi A6 Quattro on new tires, confirm that the installed size matches the wheel diameter and that each tire is seated correctly on the rim. Tire pressure should be set properly, and the wheels should be checked for damage, bent flanges, or other issues that could affect sealing or balance. Lug torque and general suspension condition also deserve attention.

A short test drive should include listening for rubbing, feeling for vibration, and checking that the steering remains smooth and centered. After a few miles, it is smart to recheck pressure and look for any sign of contact around the inner fender, suspension, or wheel liner. That is especially worthwhile on cars wearing 19-inch or 20-inch wheel packages.

Tires on a 2018 Audi A6 Quattro should be inspected regularly, not just when tread looks low. A visual check for uneven wear, cuts, punctures, bulges, and sidewall damage is good practice throughout the year, especially on a car that may alternate between daily use and longer parked periods. Pressure loss should also be watched closely on low-profile fitments.

Inspection becomes even more important if the car has larger wheels, lower-profile tires, or a modified suspension. Checking tread wear across the full width of the tire can also reveal alignment or inflation issues before they become expensive. Frequent inspections help preserve ride quality, protect the wheels, and catch small problems before a longer road trip exposes them.