2018 BMW 3 Series Tire Pressure
OEM cold pressure spec — verified for the 2012–2018 generation.
Always verify against the sticker inside your driver's door — different trims, option packages, or a spare tire may have different specifications.
2018 BMW 3 Series tire size: 225/50R17
The factory (base-trim) tire size for the 2018 BMW 3 Series is 225/50R17. Here is what that size measures out to in the real world — useful when comparing replacement tires or checking whether a different size will fit.
- Overall diameter
- 25.86"
- 657 mm
- Sidewall height
- 4.43"
- 112.5 mm
- Circumference
- 81.24"
- rolling
- Revs / mile
- 780
- approx.
Staying within ±3% of the 25.86" overall diameter keeps your speedometer accurate. A larger diameter reads slower than your true speed; a smaller one reads faster.
Tune for your load & driving style
- Front (cold)
- 25.6 PSI(1.76 bar)
- Rear (cold)
- 25.6 PSI(1.76 bar)
- Front (hot est.)
- 28.1 PSI
- Rear (hot est.)
- 28.1 PSI
Street setting: balanced for comfort, wear, and fuel economy. Always measure cold.
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2018 BMW 3 Series
- What is the recommended tire pressure for a 2018 BMW 3 Series?
- The 2018 BMW 3 Series uses 35 PSI cold on the front axle and 38 PSI cold on the rear axle. These are the OEM specifications. Always measure tire pressure when the tires are cold — before driving or after sitting for at least 3 hours.
- What tire size does the 2018 BMW 3 Series use?
- The standard (base trim) tire size for the 2018 BMW 3 Series is 225/50R17. Higher trim levels and optional packages may use a different size — check the sticker inside your driver's door for the exact specification for your vehicle.
- How do I convert the 2018 BMW 3 Series tire pressure to bar?
- 35 PSI = 2.4 bar (front) and 38 PSI = 2.6 bar (rear). In kPa: 241 kPa front and 262 kPa rear. Multiply PSI × 0.0689 to convert to bar.
- Why are the front and rear tire pressures different on the 2018 BMW 3 Series?
- The 2018 BMW 3 Series uses 35 PSI front and 38 PSI rear because the two axles carry different loads. The front axle carries roughly 50% of the vehicle's 1545 kg curb weight, requiring a slightly different pressure to maintain the correct contact patch at each corner.
- What happens if the 2018 BMW 3 Series tires are underinflated?
- Running 5+ PSI low on the BMW 3 Series causes uneven shoulder wear, increased rolling resistance (worse fuel economy), higher tire operating temperature, and reduced wet braking performance. In extreme cases, chronic underinflation can cause sidewall failure. Check pressure monthly and always after a large temperature swing.
- What do the numbers in 225/50R17 mean on the 2018 BMW 3 Series?
- On the 2018 BMW 3 Series, 225/50R17 breaks down as: 225 = section width in millimetres (8.86"), 50 = aspect ratio (the sidewall is 50% of the width, so 112.5 mm / 4.43" tall), R = radial construction, and 17 = the wheel diameter in inches.
- What is the overall diameter of the 2018 BMW 3 Series tires?
- The 225/50R17 tire on the 2018 BMW 3 Series has an overall diameter of about 25.86" (657 mm) and a rolling circumference of roughly 81.24", giving about 780 revolutions per mile. Fitting a tire with a different diameter will throw off your speedometer and odometer.