255/50R20 · SUV / crossover · Bar
Recommended bar for 255/50R20
- Size
- 255/50R20
- Class
- SUV / crossover
- Planning PSI
- 36
- Planning bar
- 2.48
bar
2.48
36 psi · 248 kPa · not a second factory sticker
255/50R20 · 36 psi · 2.48 bar · 248 kPa — estimates. Placard wins.
A 255/50R20 C-type or LT carcass can live far above a hatchback bar figure. This page’s 2.48 bar sketch is for the SUV / crossover class, not every car that can physically mount the tyre. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed 255/50R20.
Bar, PSI and kPa
Use the table, then set a cold gauge. 248 kPa is 100 × 2.48 bar on this size.
| Bar | PSI | kPa |
|---|---|---|
| 2.21 | 32 | 221 |
| 2.28 | 33 | 228 |
| 2.34 | 34 | 234 |
| 2.41 | 35 | 241 |
| 2.48 | 36 | 248 |
| 2.55 | 37 | 255 |
| 2.62 | 38 | 262 |
| 2.69 | 39 | 269 |
| 2.76 | 40 | 276 |
| 2.83 | 41 | 283 |
| 2.90 | 42 | 290 |
| 2.96 | 43 | 296 |
| 3.03 | 44 | 303 |
| 3.10 | 45 | 310 |
| 3.17 | 46 | 317 |
| 3.24 | 47 | 324 |
| 3.31 | 48 | 331 |
Estimated 255/50R20 pressure by load
Plus-sizing to 255/50R20 from a taller OEM tyre usually keeps the same placard if the load index is equal or higher.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 36 psi / 2.48 bar / 248 kPa | 37 psi / 2.55 bar / 255 kPa |
| Typical occupancy | 36 psi / 2.48 bar / 248 kPa | 38 psi / 2.62 bar / 262 kPa |
| Motorway + luggage (sketch) | 37 psi / 2.55 bar / 255 kPa | 39 psi / 2.69 bar / 269 kPa |
Placard versus sidewall
If a forum says “all 255/50R20 run 36 psi”, ignore it. A Qashqai and a Golf can share a size and not share a sticker.
What 255/50R20 means
Read 255/50R20 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.
20-inch plus-size SUV. Rim diameter 20 in; section 255 mm. Estimates on this page assume a typical load index for the SUV / crossover class.
Cars often seen on 255/50R20
These catalogue models are often seen on 255/50R20 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.
How to set 255/50R20
- Park so the 255/50R20 tyres are cold (three hours, or less than about a mile).
- Read the door-pillar placard for that car — not the 255/50R20 sidewall maximum.
- If the sticker is missing, 36 psi / 2.48 bar is only a SUV / crossover planning figure for this size.
- Set all four with a calibrated gauge. A 3 psi miss on one corner shows up as a wander.
- Refit valve caps and reset TPMS if the handbook asks for a relearn.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 36 psi as a 20 °C baseline for 255/50R20.
| Ambient | Gauge | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 33 psi | 2.28 bar | 228 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 34 psi | 2.34 bar | 234 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 35 psi | 2.41 bar | 241 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 36 psi | 2.48 bar | 248 kPa | Baseline for this size sketch |
| 30 °C | 38 psi | 2.62 bar | 262 kPa | Do not bleed a hot 255/50R20 |
| 38 °C (heatwave tarmac) | 39 psi | 2.69 bar | 269 kPa | Do not bleed a hot 255/50R20 |
Keep 255/50R20 on the printed band for that car; 36 psi is a size sketch, not a second VIN label.
Questions about 255/50R20
Is the sidewall number correct for 255/50R20?
No. Sidewall PSI or kPa is a maximum for the carcass. Operating pressure is the door-pillar placard.
When does TPMS warn on 255/50R20?
Direct TPMS typically flags about 25% below target — near 27 psi if you were aiming at 36. Fill to the sticker, not to the lamp.
Is 255/50R20 the same as a plus-size swap?
Only if that is the size you fitted. Overall diameter should stay close to OEM. Pressure still follows the car, with load index at or above original.
What PSI should 255/50R20 tyres be?
A SUV / crossover planning figure is about 36 psi cold (2.48 bar / 248 kPa). Confirm on the vehicle placard — two cars can share 255/50R20 and not share a sticker.
Can I run 255/50R20 at a lower pressure for comfort?
Not as a habit. A soft 255/50R20 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
Handbook: placard · bar vs PSI · cold inflation · all sizes