225/45R17 · passenger car · kPa
225/45R17 kPa inflation table
- Size
- 225/45R17
- Class
- passenger car
- Planning PSI
- 35
- Planning bar
- 2.41
kPa
241
2.41 bar · 35 psi · 100 kPa = 1 bar
225/45R17 · 35 psi · 2.41 bar · 241 kPa — estimates. Placard wins.
Kilopascals show up on some Asian stickers and ISO sheets. 241 kPa is the planning midpoint for 225/45R17 (2.41 bar / 35 psi). 100 kPa = 1 bar. TPMS typically warns near 26 psi (about 25% below a 35 psi target). That is already a soft tyre. Low-profile {sz} does not want a “softer” pressure to recover ride. Stay at or slightly above the car’s original placard if load index is kept.
kPa, bar and PSI
Convert around the 225/45R17 band. 2.41 bar is about 35 psi — not 23, not 33 unless the maths says so.
| kPa | Bar | PSI |
|---|---|---|
| 214 | 2.14 | 31 |
| 221 | 2.21 | 32 |
| 228 | 2.28 | 33 |
| 234 | 2.34 | 34 |
| 241 | 2.41 | 35 |
| 248 | 2.48 | 36 |
| 255 | 2.55 | 37 |
| 262 | 2.62 | 38 |
| 269 | 2.69 | 39 |
| 276 | 2.76 | 40 |
| 283 | 2.83 | 41 |
| 290 | 2.90 | 42 |
| 296 | 2.96 | 43 |
| 303 | 3.03 | 44 |
| 310 | 3.10 | 45 |
| 317 | 3.17 | 46 |
| 324 | 3.24 | 47 |
Estimated 225/45R17 pressure by load
These 225/45R17 load steps are ± a few PSI from 35. They are not a licence to ignore a printed second column on a van or estate.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 35 psi / 2.41 bar / 241 kPa | 35 psi / 2.41 bar / 241 kPa |
| Typical occupancy | 36 psi / 2.48 bar / 248 kPa | 37 psi / 2.55 bar / 255 kPa |
| Motorway + luggage (sketch) | 37 psi / 2.55 bar / 255 kPa | 38 psi / 2.62 bar / 262 kPa |
What 225/45R17 means
225/45R17 means a 225 millimetre section width, a sidewall that is 45 percent of that width, on a 17-inch rim. The R is radial construction.
The default 17-inch sport / saloon size. Rim diameter 17 in; section 225 mm. Estimates on this page assume a typical load index for the passenger car class.
Placard versus sidewall
If a forum says “all 225/45R17 run 35 psi”, ignore it. A Qashqai and a Golf can share a size and not share a sticker.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 35 psi as a 20 °C baseline for 225/45R17.
| Ambient | Gauge | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 32 psi | 2.21 bar | 221 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 33 psi | 2.28 bar | 228 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 34 psi | 2.34 bar | 234 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 35 psi | 2.41 bar | 241 kPa | Baseline for this size sketch |
| 30 °C | 37 psi | 2.55 bar | 255 kPa | Do not bleed a hot 225/45R17 |
| 38 °C (heatwave tarmac) | 38 psi | 2.62 bar | 262 kPa | Do not bleed a hot 225/45R17 |
How to set 225/45R17
- Park so the 225/45R17 tyres are cold (three hours, or less than about a mile).
- Read the door-pillar placard for that car — not the 225/45R17 sidewall maximum.
- If the sticker is missing, 35 psi / 2.41 bar is only a passenger car 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.
Cars often seen on 225/45R17
These catalogue models are often seen on 225/45R17 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.
A cheap gauge and a monthly habit will do more for a set of 225/45R17 than nitrogen upsells.
Questions about 225/45R17
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 225/45R17?
Direct TPMS typically flags about 25% below target — near 26 psi if you were aiming at 35. Fill to the sticker, not to the lamp.
Is 225/45R17 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.
Can I run 225/45R17 at a lower pressure for comfort?
Not as a habit. A soft 225/45R17 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
What PSI should 225/45R17 tyres be?
A passenger car planning figure is about 35 psi cold (2.41 bar / 241 kPa). Confirm on the vehicle placard — two cars can share 225/45R17 and not share a sticker.
Handbook: placard · bar vs PSI · cold inflation · all sizes