UK · EU reference Tyre Pressure

225/40R17 · passenger car · kPa

225/40R17 tyre pressure in kPa

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

kPa

248

2.48 bar · 36 psi · 100 kPa = 1 bar

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

Kilopascals show up on some Asian stickers and ISO sheets. 248 kPa is the planning midpoint for 225/40R17 (2.48 bar / 36 psi). 100 kPa = 1 bar. 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.

kPa, bar and PSI

Use the table, then set a cold gauge. 248 kPa is 100 × 2.48 bar on this size.

kPaBarPSI
2212.2132
2282.2833
2342.3434
2412.4135
2482.4836
2552.5537
2622.6238
2692.6939
2762.7640
2832.8341
2902.9042
2962.9643
3033.0344
3103.1045
3173.1746
3243.2447
3313.3148

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 occupancy37 psi / 2.55 bar / 255 kPa38 psi / 2.62 bar / 262 kPa
Motorway + luggage (sketch)38 psi / 2.62 bar / 262 kPa39 psi / 2.69 bar / 269 kPa

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.

Placard versus sidewall

This website maps size searches such as “225/40R17 psi”. It does not replace the VIN label. If the two disagree, the label wins.

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

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.

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.

Keep 225/40R17 on the printed band for that car; 36 psi is a size sketch, not a second VIN label.

Questions about 225/40R17

What is 225/40R17 in bar?

36 psi is 2.48 bar. Add a tenth of a bar if the placard’s laden column is higher, which is common on vans that wear this size.

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.

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.

What is 225/40R17 in kPa?

248 kPa is the planning midpoint (100 kPa = 1 bar). 255 kPa is one PSI higher.

Handbook: placard · bar vs PSI · cold inflation · all sizes