2008 BMW X3 — 3.0si Sport Package
The 2008 BMW X3 3.0si Sport Package shipped with 3 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.
235/50R18
| Section width | 235 mm |
|---|---|
| Aspect ratio (sidewall height) | 50% (117.5 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~27.3" |
| Revolutions per mile | ~740 |
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235/45R19 (Front)
| Section width | 235 mm |
|---|---|
| Aspect ratio (sidewall height) | 45% (105.8 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~27.3" |
| Revolutions per mile | ~738 |
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255/40R19 (Rear)
| 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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What this size means for your BMW X3
On the 2008 BMW X3 3.0si Sport Package, the factory 235/50R18 measures about 27.3″ in overall diameter with a 117.5 mm (4.6″) sidewall, and completes roughly 740 revolutions per mile. Its 50-series aspect ratio gives a balanced everyday-passenger profile — enough sidewall to soak up road shock while keeping steering response crisp. In tire terms it is a passenger (P-metric / Euro-metric) size.
The 235/50R18 and 235/45R19 roll within 0″ (0%) 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.
On a vehicle of this age, the BMW X3 may have been refitted with a slightly different replacement size somewhere in its life, so check the current sidewall — not just the factory spec — before buying.
Other 2008 BMW X3 trims
- 3.0si Base Model 235/55R17 / 235/50R18
BMW X3 tire sizes by year
- 2026 BMW X3 245/50R19 / 255/45R20 (Front) / 285/40R20 (Rear) / 255/40R21 (Front) / 285/35R21 (Rear)
- 2025 BMW X3 245/50R19 / 255/45R20 (Front) / 285/40R20 (Rear) / 255/40R21 (Front) / 285/35R21 (Rear)
- 2024 BMW X3 255/45R20 (Front) / 265/45R20 (Rear) / 255/40R21 (Front) / 265/40R21 (Rear)
- 2023 BMW X3 255/45R20 (Front) / 265/45R20 (Rear) / 255/40R21 (Front) / 265/40R21 (Rear)
- 2022 BMW X3 255/45R20 (Front) / 265/45R20 (Rear) / 255/40R21 (Front) / 265/40R21 (Rear)
- 2021 BMW X3 255/45R20 (Front) / 265/45R20 (Rear) / 255/40R21 (Front) / 265/40R21 (Rear)
- 2020 BMW X3 255/45R20 (Front) / 265/45R20 (Rear) / 255/40R21 (Front) / 265/40R21 (Rear)
- 2019 BMW X3 245/50R19 / 245/45R20 (Front) / 275/40R20 (Rear) / 245/40R21 (Front) / 275/35R21 (Rear)
- 2018 BMW X3 245/50R19 / 245/45R20 (Front) / 275/40R20 (Rear) / 245/40R21 (Front) / 275/35R21 (Rear)
- 2017 BMW X3 245/50R18 / 245/45R19
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.