The 2018 Audi A6 sits in the modern sport-luxury sedan category, blending understated executive styling with the road manners buyers expect from a contemporary German performance sedan. For tire selection, that means fitment is tied closely to the wheel package on the car rather than a single universal size. The 2018 Audi A6 uses radial tires in three primary sizes: 245/45R18, 255/40R19, and 255/35R20. Available choices range from blackwall performance-oriented radials to raised white letter and redline options in the larger sizes. The key is matching the exact wheel diameter and setup on the car before choosing for appearance, handling character, or everyday road use.
Which Tire Size Is Right for The 2018 Audi A6
The 2018 Audi A6 uses three primary tire sizes, and the right one depends first on the exact wheel diameter on the car. All three are metric radial sizes, but they span 18-inch, 19-inch, and 20-inch fitments, with some variation by sub-model. Before choosing a tire, confirm whether the car is on 18-, 19-, or 20-inch wheels and then compare the available brands, series, and sidewall treatments within that size.
In 245/45R18, the 245 identifies the tire's nominal section width in millimeters, 45 is the aspect ratio, R denotes radial construction, and 18 is the wheel diameter in inches. On the 2018 Audi A6, this is the 18-inch radial fitment and suits cars equipped with the smaller wheel package. Available choices center on blackwall performance radials from BFGoodrich and Nitto across series such as g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, and NT555 G2. This size is the one to evaluate when maintaining the 18-inch setup rather than moving to a larger wheel diameter.
In 255/35R20, the 255 is the nominal section width in millimeters, 35 is the aspect ratio, R marks radial construction, and 20 indicates a 20-inch wheel. For the 2018 Audi A6, this size belongs to the largest primary wheel package covered here and gives buyers a wider selection of appearance treatments. Along with blackwall choices from BFGoodrich, Nitto, and Pro-Trac, this size is also available with raised white letter and redline sidewalls in the Street Pro III series. It is the correct place to start when the car already wears 20-inch wheels and the goal is to balance style with proper size matching.
In 255/40R19, the first number is the nominal section width in millimeters, 40 is the aspect ratio, R means radial, and 19 identifies a 19-inch rim. On the 2018 Audi A6, this 19-inch radial size shares the same nominal width as the 20-inch option but is built for a different wheel diameter. Product choices include blackwall BFGoodrich offerings in several g-Force series as well as Pro-Trac Street Pro III options with raised white letter or redline sidewalls. This size deserves a close look when the car uses 19-inch wheels and the buyer wants either a conventional blackwall presentation or a more distinctive sidewall style.
Sub-model fitment on the 2018 Audi A6 is mostly straightforward, but it is not identical across every version. Premium and Premium Plus can use all three sizes, while the Sport trim is limited to the 19-inch and 20-inch radial fitments, so confirming the exact sub-model and wheel package still matters.
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2018 Audi A6 Premium
The 2018 Audi A6 Premium can use 18-inch, 19-inch, or 20-inch radial tire fitments depending on the wheel setup on the car. Tire selection starts with confirming actual wheel diameter, then narrowing the choice by brand, series, and whether a blackwall, raised white letter, or redline sidewall suits the car's intended look.
The 2018 Audi A6 Premium Plus shares the same broad fitment pattern as the Premium, with 18-inch, 19-inch, and 20-inch radial sizes used across covered configurations. That makes wheel confirmation the first step, followed by comparing the available performance-oriented tire lines and sidewall treatments within the correct size.
The 2018 Audi A6 Sport uses the larger radial fitments and does not share the 18-inch size used elsewhere in the range. For this sub-model, tire selection centers on confirming whether the car is on 19-inch or 20-inch wheels and then choosing among blackwall, raised white letter, or redline options where available.
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 2018 Audi A6 Tires for Sale
Available 2018 Audi A6 tires span 245/45R18, 255/40R19, and 255/35R20 radial fitments from BFGoodrich, Nitto, and Pro-Trac. Buyers can compare blackwall performance series such as g-Force and NT555 G2, with raised white letter and redline options offered in the larger sizes.
These FAQs focus on the 2018 Audi A6 tire sizes, wheel-diameter differences, product selection, sidewall choices, and the fitment checks that matter before putting the car back on the road.
Tire Size & Fitment
What tire size fits a 2018 Audi A6?
The 2018 Audi A6 uses three primary radial tire sizes: 245/45R18, 255/40R19, and 255/35R20. The correct one depends on the wheel package on the car, since these sizes are tied to different rim diameters rather than being interchangeable versions of the same fitment.
Start by checking the wheel diameter actually installed on the car and then match the tire size to that rim. Premium and Premium Plus can use all three sizes, while Sport uses the 19-inch and 20-inch fitments, so trim and wheel setup both matter before choosing a tire.
What size rim does a 2018 Audi A6 use?
The 2018 Audi A6 uses 18-inch, 19-inch, or 20-inch rims, depending on the tire size and vehicle configuration. The 245/45R18 fits an 18-inch wheel, the 255/40R19 fits a 19-inch wheel, and the 255/35R20 fits a 20-inch wheel.
Wheel diameter should be confirmed before anything else because the three primary sizes are built for different rims. If the car has been changed from its original wheel package, read the wheel and tire markings directly so the next tire purchase matches the actual setup rather than the trim name alone.
Do all 2018 Audi A6 sub-models use the same tire size?
No. The 2018 Audi A6 Premium and Premium Plus can use 245/45R18, 255/40R19, or 255/35R20, while the Sport trim uses 255/40R19 and 255/35R20. That means the covered sub-models overlap, but they do not all share the same full range of tire sizes.
This matters because a buyer cannot assume every A6 in this model year takes the same tire just because the body style looks the same. Check the exact sub-model and the current wheel diameter, especially if the car has optional wheels or has been changed since new.
Choosing the Right Tire
What should I consider when choosing a 2018 Audi A6 tire?
Begin with the correct tire size for the wheel on the car: 245/45R18, 255/40R19, or 255/35R20. From there, compare radial construction details such as brand, tire series, rim-width compatibility where stated, weight, and any load figures that appear in the product specifications.
The best choice depends on how the A6 is used and how the owner wants it to look. Some buyers will want a straightforward blackwall performance radial, while others may prefer the visual character of raised white letter or redline sidewalls in the larger 19-inch and 20-inch sizes.
What sidewall styles are available for 2018 Audi A6 tires?
Sidewall choices for the 2018 Audi A6 include blackwall across all three primary sizes, plus raised white letter and redline treatments in the 255/40R19 and 255/35R20 fitments. Those larger sizes offer more visual variety than the 245/45R18 fitment, which stays with blackwall-only options.
Appearance can change the car's presentation more than many buyers expect, so the sidewall style is worth choosing deliberately. A blackwall keeps a more understated modern look, while raised white letter or redline options create a much more noticeable visual statement without changing the underlying size category.
What brands offer tires for the 2018 Audi A6?
The 2018 Audi A6 tire options here come from BFGoodrich, Nitto, and Pro-Trac. BFGoodrich appears across all three sizes in several g-Force series, Nitto is available in the NT555 G2 line, and Pro-Trac appears in the larger 19-inch and 20-inch fitments.
Brand is only one part of the choice, so compare it alongside tire series, sidewall style, and wheel compatibility. On this A6, that matters because the 18-inch fitment has a different mix of options than the 19-inch and 20-inch sizes, especially if sidewall appearance is part of the decision.
Restoration & Appearance
Which tire should I choose for a period-style 2018 Audi A6?
A period-style approach on a 2018 Audi A6 usually starts with keeping the correct wheel diameter and matching tire size already used on the car, whether that is 245/45R18, 255/40R19, or 255/35R20. Since this is a modern radial-fitment car, the main appearance decision is typically within the available radial product styles rather than between vintage constructions.
For a restrained, factory-inspired look, blackwall tires are the most natural visual fit. Buyers who want a stronger custom presentation can look at the raised white letter or redline options in the 19-inch and 20-inch sizes, but the wheel package should still be confirmed first so appearance does not override proper fitment.
How does tire choice affect the appearance of a 2018 Audi A6?
Tire choice affects a 2018 Audi A6 visually through wheel diameter, sidewall height, and sidewall treatment. An 18-inch setup presents the car differently than the 19-inch and 20-inch packages, and blackwall, raised white letter, and redline options can further shift the car from understated executive sedan to a more customized look.
That makes size selection and style selection separate decisions. First keep the tire matched to the wheel on the car, then choose the sidewall presentation that suits the build. On a newer collector or enthusiast A6, that balance often matters just as much as brand when shaping the finished appearance.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 2018 Audi A6?
Yes. Wheel changes, suspension lowering, altered offset, or body modifications can affect how 245/45R18, 255/40R19, or 255/35R20 tires sit on a 2018 Audi A6. Even when the tire size is correct in principle, a modified car can have different clearance conditions than a stock vehicle.
Check wheel diameter, wheel width, and the tire's relationship to the fenders, struts, and steering components before finalizing a replacement. That is especially important if the A6 has aftermarket wheels, because the correct size category alone does not guarantee the same inboard and outboard clearance.
What should I inspect before driving a 2018 Audi A6 on new tires?
Before road use, inspect inflation pressure, tread condition, bead seating, and overall sidewall condition, and make sure all four tires match the wheel diameters installed on the car. It is also wise to confirm there are no cuts, bulges, or signs of mounting damage before the first serious drive.
A quick clearance check at full steering lock is worthwhile on any A6, especially if the car uses 19-inch or 20-inch wheels or has been modified. After the first miles, recheck pressure and look for any rubbing or uneven wear so small fitment problems are caught before they become larger issues.
How often should tires on a 2018 Audi A6 be inspected?
Tires on a 2018 Audi A6 should be inspected regularly, not just when tread looks low. A visual check for pressure loss, uneven wear, cuts, cracking, and sidewall damage should become routine, especially on a car that sees seasonal use or long periods of sitting between drives.
Stored enthusiast cars can age their tires without adding many miles, so condition matters as much as mileage. Make a habit of checking the tires before longer trips and after storage, paying close attention to any changes in ride feel or visible wear that could point to alignment, inflation, or clearance issues.
