BMW · M550 · Rear
BMW M550 rear tyre pressure
- Drivetrain
- rear-wheel drive
- Body
- passenger car
- PSI F / R
- 32-35 / 32-35
- Bar F / R
- 2.2-2.4 / 2.2-2.4
psi rear
34
2.31 bar · 231 kPa at the rear axle
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
Loaded M550 rears often need the sticker’s second column, not a copy of the front 32-35 psi figure. Under-inflation cooks the shoulders of a M550; over-inflation wears the centre rib and bangs every cat’s eye.
BMW M550 placard versus sidewall
Sidewall PSI is a carcass maximum. Recommended operating pressure for this M550 is the pillar sticker, near 34/34 psi.
Estimated pressure by tyre size (275/35R18 and others)
Planning cold pressures for sizes often seen on a passenger car. This M550 sample opens with 275/35R18, then 255/35R18 and 255/40R17.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 275/35R18 | — | 37 | — | 2.55 | — | 255 | Wide rear |
| 255/35R18 | — | 36 | — | 2.48 | — | 248 | Rear stagger 18-inch |
| 255/40R17 | — | 36 | — | 2.48 | — | 248 | Rear stagger 17-inch |
| 235/35R19 | — | 36 | — | 2.48 | — | 248 | Front 19-inch |
| 225/45R17 | — | 35 | — | 2.41 | — | 241 | Front sport size |
| 225/40R18 | — | 35 | — | 2.41 | — | 241 | Front 18-inch |
| 245/40R18 | — | 36 | — | 2.48 | — | 248 | Square-ish sport |
| 275/30R19 | — | 37 | — | 2.55 | — | 255 | Rear 19-inch |
Pressure against load
Load moves the rear of a passenger car first. If the factory placard already has a “laden” column, use that instead of these sketches.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only | 34 psi / 2.34 bar | 34 psi / 2.34 bar |
| Full occupancy | 34 psi / 2.34 bar | 35 psi / 2.41 bar |
| Motorway + luggage | 35 psi / 2.41 bar | 38 psi / 2.62 bar |
A family passenger car with a boot full of luggage should use the laden rear figure if Ford, VW or Mercedes printed one. Otherwise the modest steps in the load table are only a sketch for this M550.
How to set the M550
- Park the BMW M550 for at least three hours (cold tyres).
- Use a calibrated gauge, not the only meter on a forecourt hose.
- Set the placard for that axle — about 32-35 psi / 2.2-2.4 bar front and 32-35 psi / 2.2-2.4 bar rear on this catalogue row.
- Recheck all four. A 2 psi miss on a rear-wheel drive M550 is enough to feel a pull.
- Refit valve caps and reset TPMS if the handbook asks for a relearn.
PSI, bar and kPa
PSI-led conversions for the BMW M550 band (32-35 / 32-35).
| PSI | Bar | kPa |
|---|---|---|
| 30 | 2.07 | 207 |
| 32 | 2.21 | 221 |
| 33 | 2.28 | 228 |
| 33.5 | 2.31 | 231 |
| 35 | 2.41 | 241 |
| 36 | 2.48 | 248 |
| 38 | 2.62 | 262 |
| 40 | 2.76 | 276 |
| 44 | 3.03 | 303 |
| 50 | 3.45 | 345 |
| 60 | 4.14 | 414 |
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this M550.
| Ambient | Gauge (front mid) | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 31 psi | 2.14 bar | 214 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 32 psi | 2.21 bar | 221 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 33 psi | 2.28 bar | 228 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 34 psi | 2.34 bar | 234 kPa | Baseline |
| 30 °C | 36 psi | 2.48 bar | 248 kPa | Do not bleed a hot tyre |
| 38 °C (heatwave tarmac) | 37 psi | 2.55 bar | 255 kPa | Do not bleed a hot tyre |
BMW notes
BMW run-flats still want the placard. Comfort settings in the iDrive do not replace the door-pillar figure on this M550.
Spare and inflator kit
A matching full-size spare on the BMW M550 usually follows the higher axle (often the rear, near 32-35 psi). A space-saver is commonly 60 psi / 4.1 bar — read that tyre’s own sidewall. An inflator kit is not a spare; check the sealant date.
If the BMW sticker and this page disagree, the sticker wins.
Other BMW models
Questions about this M550
What is that in bar and kPa for the M550?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
How often should I check a M550?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Front versus rear on the BMW M550?
This row is 32-35 F / 32-35 R. Even when they match, a laden rear can justify a higher number if the sticker prints one.
When does TPMS warn on a BMW M550?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
What tyre pressure should a BMW M550 use?
Catalogue reference is 32-35 psi front and 32-35 psi rear (2.2-2.4 / 2.2-2.4 bar), cold. Confirm on the door-pillar placard.
Handbook: placard · bar vs PSI · front vs rear · cold inflation