2019 BMW Alpina — B6 xDrive Gran Coupe
The 2019 BMW Alpina B6 xDrive Gran Coupe shipped with 4 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.
255/35R20 (Front)
| Section width | 255 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (89.3 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~27" |
| Revolutions per mile | ~746 |
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295/30R20 (Rear)
| Section width | 295 mm |
|---|---|
| Aspect ratio (sidewall height) | 30% (88.5 mm) |
| Rim diameter | 20" |
| Overall tire diameter | ~27" |
| Revolutions per mile | ~748 |
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245/35R21 (Front)
| Section width | 245 mm |
|---|---|
| Aspect ratio (sidewall height) | 35% (85.8 mm) |
| Rim diameter | 21" |
| Overall tire diameter | ~27.8" |
| Revolutions per mile | ~727 |
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285/30R21 (Rear)
| Section width | 285 mm |
|---|---|
| Aspect ratio (sidewall height) | 30% (85.5 mm) |
| Rim diameter | 21" |
| Overall tire diameter | ~27.7" |
| Revolutions per mile | ~727 |
Compare prices at:
What this size means for your BMW Alpina
On the 2019 BMW Alpina B6 xDrive Gran Coupe, the factory 255/35R20 measures about 27″ in overall diameter with a 89.3 mm (3.5″) sidewall, and completes roughly 746 revolutions per mile. Its 35-series aspect ratio gives an ultra-low-profile, performance-oriented sidewall that favors steering precision over ride cushioning. In tire terms it is a large-diameter fitment.
This is a staggered setup: the front axle runs 255/35R20 and the rear runs 295/30R20. The two sizes are not interchangeable, so order each for its correct axle and don't rotate front-to-rear.
Other 2019 BMW Alpina trims
- B7 xDrive 255/40R20 (Front) / 295/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
BMW Alpina tire sizes by year
- 2025 BMW Alpina 245/40R20 (Front) / 275/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2024 BMW Alpina 245/40R20 (Front) / 275/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2023 BMW Alpina 245/40R20 (Front) / 275/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2022 BMW Alpina 255/40R20 (Front) / 295/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2021 BMW Alpina 255/40R20 (Front) / 295/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2020 BMW Alpina 255/40R20 (Front) / 295/35R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2018 BMW Alpina 255/35R20 (Front) / 295/30R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2017 BMW Alpina 255/35R20 (Front) / 295/30R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2016 BMW Alpina 255/35R20 (Front) / 295/30R20 (Rear) / 245/35R21 (Front) / 285/30R21 (Rear)
- 2013 BMW Alpina 245/35R21 (Front) / 285/30R21 (Rear)
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.