2010 BMW 550i — xDrive Gran Turismo Base Model
The 2010 BMW 550i xDrive Gran Turismo Base Model came from the factory equipped with 245/50R18 tires. If your vehicle has since been fitted with aftermarket or upsized wheels, your actual tire size may no longer match this factory spec — always confirm against your door placard before buying.
245/50R18
| Section width | 245 mm |
|---|---|
| Aspect ratio (sidewall height) | 50% (122.5 mm) |
| Rim diameter | 18" |
| Overall tire diameter | ~27.6" |
| Revolutions per mile | ~730 |
Compare prices at:
What this size means for your BMW 550i
On the 2010 BMW 550i xDrive Gran Turismo Base Model, the factory 245/50R18 measures about 27.6″ in overall diameter with a 122.5 mm (4.8″) sidewall, and completes roughly 730 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.
On a vehicle of this age, the BMW 550i 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 2010 BMW 550i trims
- Gran Turismo Base Model 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- Gran Turismo Sport Package 245/45R19 (Front) / 275/40R19 (Rear) / 245/40R20 (Front) / 275/35R20 (Rear)
- Sedan Base Model 225/50R17 / 245/35R19 (Front) / 275/30R19 (Rear)
- Sedan Sport Package 245/35R19 (Front) / 275/30R19 (Rear)
BMW 550i tire sizes by year
- 2017 BMW 550i 245/50R18 / 245/45R19
- 2016 BMW 550i 245/45R18 / 245/40R19
- 2015 BMW 550i 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- 2014 BMW 550i 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- 2013 BMW 550i 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- 2012 BMW 550i 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- 2011 BMW 550i 245/50R18 / 245/45R19 (Front) / 275/40R19 (Rear)
- 2009 BMW 550i 225/50R17 / 245/35R19 (Front) / 275/30R19 (Rear)
- 2008 BMW 550i 225/50R17
- 2007 BMW 550i 225/50R17
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.