225/60R18 · SUV / crossover · PSI
225/60R18 tyre pressure in PSI
- Size
- 225/60R18
- Class
- SUV / crossover
- Planning PSI
- 34
- Planning bar
- 2.34
psi
34
2.34 bar · 234 kPa · SUV / crossover planning figure
225/60R18 · 34 psi · 2.34 bar · 234 kPa — estimates. Placard wins.
If someone typed “225/60R18 psi”, they want Imperial. Start near 34 psi on an unladen SUV / crossover, then confirm the vehicle placard. Sidewall max is not the target. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed 225/60R18.
Estimated 225/60R18 pressure by load
These 225/60R18 load steps are ± a few PSI from 34. They are not a licence to ignore a printed second column on a van or estate.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 34 psi / 2.34 bar / 234 kPa | 35 psi / 2.41 bar / 241 kPa |
| Typical occupancy | 35 psi / 2.41 bar / 241 kPa | 37 psi / 2.55 bar / 255 kPa |
| Motorway + luggage (sketch) | 36 psi / 2.48 bar / 248 kPa | 38 psi / 2.62 bar / 262 kPa |
PSI, bar and kPa
Use the table, then set a cold gauge. 234 kPa is 100 × 2.34 bar on this size.
| PSI | Bar | kPa |
|---|---|---|
| 30 | 2.07 | 207 |
| 31 | 2.14 | 214 |
| 32 | 2.21 | 221 |
| 33 | 2.28 | 228 |
| 34 | 2.34 | 234 |
| 35 | 2.41 | 241 |
| 36 | 2.48 | 248 |
| 37 | 2.55 | 255 |
| 38 | 2.62 | 262 |
| 39 | 2.69 | 269 |
| 40 | 2.76 | 276 |
| 41 | 2.83 | 283 |
| 42 | 2.90 | 290 |
| 43 | 2.96 | 296 |
| 44 | 3.03 | 303 |
| 45 | 3.10 | 310 |
| 46 | 3.17 | 317 |
What 225/60R18 means
Read 225/60R18 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.
Crossover / SUV highway size. Rim diameter 18 in; section 225 mm. Estimates on this page assume a typical load index for the SUV / crossover class.
Placard versus sidewall
If a forum says “all 225/60R18 run 34 psi”, ignore it. A Qashqai and a Golf can share a size and not share a sticker.
Cars often seen on 225/60R18
225/60R18 is a valid metric size in this register even if it is not on the curated OEM shortlist. Treat the 34 psi / 2.34 bar figure as a class estimate and confirm on the vehicle that actually wears it.
How to set 225/60R18
- Measure before the school run, not after the motorway.
- Write LF / RF / RR / RL. Do not keep 225/60R18 numbers in your head.
- Add air in short bursts toward the placard, using 34 psi only as a map.
- If one 225/60R18 is 4 psi down, hunt for a nail before you blame the weather.
- Log date, ambient temperature and the four readings.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for 225/60R18.
| Ambient | Gauge | 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 for this size sketch |
| 30 °C | 36 psi | 2.48 bar | 248 kPa | Do not bleed a hot 225/60R18 |
| 38 °C (heatwave tarmac) | 37 psi | 2.55 bar | 255 kPa | Do not bleed a hot 225/60R18 |
Keep 225/60R18 on the printed band for that car; 34 psi is a size sketch, not a second VIN label.
Questions about 225/60R18
When does TPMS warn on 225/60R18?
Direct TPMS typically flags about 25% below target — near 26 psi if you were aiming at 34. Fill to the sticker, not to the lamp.
Is 225/60R18 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 is 225/60R18 in kPa?
234 kPa is the planning midpoint (100 kPa = 1 bar). 241 kPa is one PSI higher.
Is the sidewall number correct for 225/60R18?
No. Sidewall PSI or kPa is a maximum for the carcass. Operating pressure is 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.
Handbook: placard · bar vs PSI · cold inflation · all sizes