225/60R18 · SUV / crossover · Overview
225/60R18: PSI, bar and kPa
- Size
- 225/60R18
- Class
- SUV / crossover
- Planning PSI
- 34
- Planning bar
- 2.34
225/60R18
34 psi / 2.34 bar
234 kPa · estimates for this size class
225/60R18 · 34 psi · 2.34 bar · 234 kPa — estimates. Placard wins.
225/60R18 is a SUV / crossover size (225 mm section, 60 % aspect, 18-inch rim). A planning cold figure around 34 psi / 2.34 bar / 234 kPa is a starting map, not a second factory sticker. Crossover / SUV highway size. These rows are estimates interpolated for the size, not OEM for a named VIN.
What 225/60R18 means
A 225/60R18 on a SUV / crossover is a geometry. Two cars can share the size and disagree on PSI because mass and axle split differ.
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.
Estimated 225/60R18 pressure by load
Load moves the rear first on a SUV / crossover. If the factory placard already has a laden column, use that — not this sketch for 225/60R18.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 34 psi / 2.34 bar / 234 kPa | 35 psi / 2.41 bar / 241 kPa |
| Typical occupancy | 34 psi / 2.34 bar / 234 kPa | 36 psi / 2.48 bar / 248 kPa |
| Motorway + luggage (sketch) | 35 psi / 2.41 bar / 241 kPa | 37 psi / 2.55 bar / 255 kPa |
PSI, bar and kPa
Convert around the 225/60R18 band. 2.34 bar is about 34 psi — not 23, not 33 unless the maths says so.
| 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 |
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
- Park so the 225/60R18 tyres are cold (three hours, or less than about a mile).
- Read the door-pillar placard for that car — not the 225/60R18 sidewall maximum.
- If the sticker is missing, 34 psi / 2.34 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 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 |
If the door sticker and this 225/60R18 page disagree, the sticker wins.
Questions about 225/60R18
Can I run 225/60R18 at a lower pressure for comfort?
Not as a habit. A soft 225/60R18 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
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.
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.
What is 225/60R18 in bar?
34 psi is 2.34 bar. Add a tenth of a bar if the placard’s laden column is higher, which is common on vans that wear this size.
Handbook: placard · bar vs PSI · cold inflation · all sizes