Porsche · 550 · Front
Front axle PSI and bar on the Porsche 550
- 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 front
34
2.31 bar · 231 kPa at the steering axle
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
The front axle of a Porsche 550 steers and, on rear-wheel drive cars, often pulls as well. Catalogue front pressure is 32-35 psi / 2.2-2.4 bar. TPMS typically warns near 25 psi (about 25% below target). That is already a soft tyre, not a fill target.
Porsche 550 placard versus sidewall
If the Porsche sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.
Estimated pressure by tyre size (205/60R16 and others)
205/60R16 is the first planning size here. 245/40R18 is usually the plus-size or LT step. Keep load index at or above original equipment.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 205/60R16 | 34 | — | 2.34 | — | 234 | — | Taller 16-inch |
| 195/65R15 | 34 | — | 2.34 | — | 234 | — | Very common compact |
| 245/40R18 | 36 | — | 2.48 | — | 248 | — | Wide touring 18-inch |
| 225/50R17 | 35 | — | 2.41 | — | 241 | — | Touring 17-inch |
| 215/55R16 | 34 | — | 2.34 | — | 234 | — | Slightly wider 16-inch |
| 215/50R17 | 35 | — | 2.41 | — | 241 | — | Plus-size 17-inch |
| 225/45R17 | 35 | — | 2.41 | — | 241 | — | Sport 17-inch |
| 225/40R18 | 36 | — | 2.48 | — | 248 | — | Low-profile 18-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 | 37 psi / 2.55 bar |
Steering feel on the 550 lives on this axle. Do not drop front pressure to “soften” a plus-size 245/40R18; you will roll the sidewall in a roundabout.
How to set the 550
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep 550 numbers in your head.
- Add air in short bursts toward 34 psi (2.31 bar) front and 34 psi rear.
- If one corner is 4 psi down, hunt for a nail before you blame the weather.
- Log date, ambient temperature and the four readings.
PSI, bar and kPa
PSI-led conversions for the Porsche 550 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 550.
| 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 |
Porsche notes
No special Porsche exception: the 550 uses the door-pillar placard. Size estimates on this page only help if you have left the original load index behind.
Spare and inflator kit
A matching full-size spare on the Porsche 550 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 Porsche sticker and this page disagree, the sticker wins.
Other Porsche models
Questions about this 550
What is that in bar and kPa for the 550?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
Front versus rear on the Porsche 550?
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.
Should I bleed pressure after a motorway run?
No. Heat raises the gauge. Set cold only. Bleeding a hot tyre leaves it low the next morning.
What tyre pressure should a Porsche 550 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.
Is the sidewall number correct on a Porsche 550?
No. Sidewall PSI is a maximum. The 550 placard is the operating target, near 32-35/32-35 psi.
Handbook: placard · bar vs PSI · front vs rear · cold inflation