UK · EU reference Tyre Pressure

225/40R17 · passenger car · Bar

225/40R17 tyre pressure in bar

Size
225/40R17
Class
passenger car
Planning PSI
36
Planning bar
2.48

bar

2.48

36 psi · 248 kPa · not a second factory sticker

225/40R17 · 36 psi · 2.48 bar · 248 kPa — estimates. Placard wins.

European stickers print bar. 225/40R17 often sits near 2.48 bar on a passenger car (36 psi / 248 kPa). 2.48 bar is not “36 divided by ten”. Low-profile 17-inch. These rows are estimates interpolated for the size, not OEM for a named VIN. 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.

Bar, PSI and kPa

Convert around the 225/40R17 band. 2.48 bar is about 36 psi — not 23, not 33 unless the maths says so.

BarPSIkPa
2.2132221
2.2833228
2.3434234
2.4135241
2.4836248
2.5537255
2.6238262
2.6939269
2.7640276
2.8341283
2.9042290
2.9643296
3.0344303
3.1045310
3.1746317
3.2447324
3.3148331

Estimated 225/40R17 pressure by load

Load moves the rear first on a passenger car. If the factory placard already has a laden column, use that — not this sketch for 225/40R17.

ConditionFront (est.)Rear (est.)
Driver only / unladen36 psi / 2.48 bar / 248 kPa36 psi / 2.48 bar / 248 kPa
Typical occupancy36 psi / 2.48 bar / 248 kPa37 psi / 2.55 bar / 255 kPa
Motorway + luggage (sketch)37 psi / 2.55 bar / 255 kPa38 psi / 2.62 bar / 262 kPa

Placard versus sidewall

If a forum says “all 225/40R17 run 36 psi”, ignore it. A Qashqai and a Golf can share a size and not share a sticker.

What 225/40R17 means

A 225/40R17 on a passenger car is a geometry. Two cars can share the size and disagree on PSI because mass and axle split differ.

Low-profile 17-inch. Rim diameter 17 in; section 225 mm. Estimates on this page assume a typical load index for the passenger car class.

Cars often seen on 225/40R17

These catalogue models are often seen on 225/40R17 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.

How to set 225/40R17

  1. Park so the 225/40R17 tyres are cold (three hours, or less than about a mile).
  2. Read the door-pillar placard for that car — not the 225/40R17 sidewall maximum.
  3. If the sticker is missing, 36 psi / 2.48 bar is only a passenger car planning figure for this size.
  4. Set all four with a calibrated gauge. A 3 psi miss on one corner shows up as a wander.
  5. 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 225/40R17.

AmbientGaugeBarkPaNote
−5 °C (hard frost)33 psi2.28 bar228 kPaGauge reads low; do not overfill once warm
0 °C34 psi2.34 bar234 kPaGauge reads low; do not overfill once warm
8 °C (UK winter morning)35 psi2.41 bar241 kPaGauge reads low; do not overfill once warm
20 °C (set cold here)36 psi2.48 bar248 kPaBaseline for this size sketch
30 °C38 psi2.62 bar262 kPaDo not bleed a hot 225/40R17
38 °C (heatwave tarmac)39 psi2.69 bar269 kPaDo not bleed a hot 225/40R17

If the door sticker and this 225/40R17 page disagree, the sticker wins.

Questions about 225/40R17

Is the sidewall number correct for 225/40R17?

No. Sidewall PSI or kPa is a maximum for the carcass. Operating pressure is the door-pillar placard.

Can I run 225/40R17 at a lower pressure for comfort?

Not as a habit. A soft 225/40R17 cooks the shoulders and dulls steering. Keep load index and stay on the placard.

Is 225/40R17 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 225/40R17 tyres be?

A passenger car planning figure is about 36 psi cold (2.48 bar / 248 kPa). Confirm on the vehicle placard — two cars can share 225/40R17 and not share a sticker.

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