2018 Audi A7 — 3.0T Prestige
The 2018 Audi A7 3.0T Prestige shipped with 2 different factory tire sizes, depending on the wheel package it left the factory with (this can also reflect a staggered front/rear setup). Check your tire sidewall or door placard to confirm which one applies to your vehicle.
This trim shipped with more than one tire size (staggered fitment, front/rear, or optional wheel package). Confirm which one matches your vehicle by checking your tire sidewall or door placard.
255/40R19
| Section width | 255 mm |
|---|---|
| Aspect ratio (sidewall height) | 40% (102 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~27" |
| Revolutions per mile | ~746 |
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265/35R20
| Section width | 265 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (92.8 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~27.3" |
| Revolutions per mile | ~739 |
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What this size means for your Audi A7
On the 2018 Audi A7 3.0T Prestige, the factory 255/40R19 measures about 27″ in overall diameter with a 102 mm (4″) sidewall, and completes roughly 746 revolutions per mile. Its 40-series aspect ratio gives a low-profile sidewall tuned for sharper handling, common on sport trims and larger-wheel packages. In tire terms it is a passenger (P-metric / Euro-metric) size.
The 255/40R19 and 265/35R20 roll within 0.3″ (1.1%) of each other in overall diameter, so they are interchangeable from a speedometer standpoint — the second size is an optional wheel package rather than a different rolling size.
Other 2018 Audi A7 trims
- 3.0T Premium Plus 255/40R19 / 265/35R20
Audi A7 tire sizes by year
- 2025 Audi A7 255/40R20
- 2024 Audi A7 255/40R20
- 2023 Audi A7 255/40R20
- 2022 Audi A7 255/40R20
- 2021 Audi A7 255/40R20
- 2020 Audi A7 245/45R19 / 255/40R20
- 2019 Audi A7 245/45R19 / 255/40R20
- 2017 Audi A7 265/35R20
- 2016 Audi A7 255/40R19 / 265/35R20
- 2015 Audi A7 255/40R19 / 265/35R20
How to read a tire size
A tire size like 225/45R17 breaks down into three parts:
the first number is the section width in millimeters
(the tire's width from sidewall to sidewall), the second is the
aspect ratio — the sidewall's height as a percentage of
that width — and the number after the "R" is the rim
diameter in inches. A letter prefix (P or LT) indicates
Passenger or Light Truck construction; its absence usually means
Euro-metric sizing.
Some trucks and off-road tires instead use "flotation" sizing, like
37X12.50R17 — here the numbers are the tire's overall
diameter and width in inches directly, with the rim diameter last.
Always verify against the tire information placard on your driver's-side door jamb or your owner's manual before purchasing — tire size can vary by factory option package even within the same trim.