Mercedes-Benz · GLS 450 · Front
Front axle PSI and bar on the Mercedes-Benz GLS 450
- Drivetrain
- all-wheel drive
- Body
- SUV / crossover
- 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
A 3 psi miss on one front corner of this GLS 450 shows up as a wander before the TPMS lamp bothers you. Target 34 psi (2.31 bar) cold. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed Mercedes-Benz tyre. Keep side-to-side spread inside about 2 psi so the all-wheel drive hardware is not working on a radius mismatch.
Mercedes-Benz GLS 450 placard versus sidewall
The tyre-information placard on a Mercedes-Benz GLS 450 sits on the driver’s door pillar (sometimes the fuel-filler flap). Catalogue figures here are a general band: 32-35 / 32-35 psi.
Estimated pressure by tyre size (225/65R17 and others)
If your Mercedes-Benz GLS 450 no longer wears the OEM diameter, start at the row nearest 225/65R17 or 225/60R18 and confirm with the tyre maker’s load table.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 225/65R17 | 35 | — | 2.41 | — | 241 | — | Very common 17-inch |
| 225/60R18 | 35 | — | 2.41 | — | 241 | — | Highway CUV |
| 255/50R20 | 37 | — | 2.55 | — | 255 | — | 20-inch plus-size |
| 245/55R19 | 36 | — | 2.48 | — | 248 | — | Low-profile 19-inch |
| 215/70R16 | 34 | — | 2.34 | — | 234 | — | Compact crossover |
| 235/60R18 | 36 | — | 2.48 | — | 248 | — | Plus-size 18-inch |
| 235/65R17 | 35 | — | 2.41 | — | 241 | — | Mid-size SUV |
| 245/60R18 | 36 | — | 2.48 | — | 248 | — | Heavier CUV |
Pressure against load
Load moves the rear of a SUV / crossover 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 |
Steering feel on the GLS 450 lives on this axle. Do not drop front pressure to “soften” a plus-size 255/50R20; you will roll the sidewall in a roundabout.
How to set the GLS 450
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep GLS 450 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 Mercedes-Benz GLS 450 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 GLS 450.
| 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 |
Mercedes-Benz notes
Mercedes often lists comfort versus load. Match the table to how the GLS 450 is actually occupied that day.
Spare and inflator kit
A matching full-size spare on the Mercedes-Benz GLS 450 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.
Keep the Mercedes-Benz GLS 450 on the printed band; use 225/65R17 and 255/50R20 only as a map for non-OEM wheels.
Other Mercedes-Benz models
Questions about this GLS 450
What tyre pressure should a Mercedes-Benz GLS 450 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.
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.
When does TPMS warn on a Mercedes-Benz GLS 450?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
Front versus rear on the Mercedes-Benz GLS 450?
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.
Is the sidewall number correct on a Mercedes-Benz GLS 450?
No. Sidewall PSI is a maximum. The GLS 450 placard is the operating target, near 32-35/32-35 psi.
Handbook: placard · bar vs PSI · front vs rear · cold inflation