2018 BMW 340i — xDrive Gran Turismo Sport Line
The 2018 BMW 340i xDrive Gran Turismo Sport Line 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.
225/50R18
| Section width | 225 mm |
|---|---|
| Aspect ratio (sidewall height) | 50% (112.5 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~26.9" |
| Revolutions per mile | ~751 |
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225/45R19
| Section width | 225 mm |
|---|---|
| Aspect ratio (sidewall height) | 45% (101.3 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~27" |
| Revolutions per mile | ~748 |
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225/45R19 (Front)
| Section width | 225 mm |
|---|---|
| Aspect ratio (sidewall height) | 45% (101.3 mm) |
| Rim diameter | 19" |
| Overall tire diameter | ~27" |
| Revolutions per mile | ~748 |
Compare prices at:
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 |
Compare prices at:
What this size means for your BMW 340i
On the 2018 BMW 340i xDrive Gran Turismo Sport Line, the factory 225/50R18 measures about 26.9″ in overall diameter with a 112.5 mm (4.4″) sidewall, and completes roughly 751 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 225/50R18 and 225/45R19 roll within 0.1″ (0.4%) 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 BMW 340i trims
- Luxury 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- M Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- Shadow Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- Track Handling Package 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- xDrive Gran Turismo Luxury 225/50R18 / 225/45R19 (Front) / 255/40R19 (Rear)
- xDrive Gran Turismo M Sport 225/50R18 / 225/50R18 (Front) / 255/45R18 (Rear) / 225/45R19 (Front) / 255/40R19 (Rear)
- xDrive Luxury 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- xDrive M Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- xDrive Shadow Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- xDrive Sport 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
BMW 340i tire sizes by year
- 2019 BMW 340i 225/50R18 / 225/45R19 / 225/45R19 (Front) / 255/40R19 (Rear)
- 2017 BMW 340i 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (Rear)
- 2016 BMW 340i 225/45R18 / 225/45R18 (Front) / 255/40R18 (Rear) / 225/40R19 (Front) / 255/35R19 (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.