UK · EU reference Tyre Pressure

245/45R17 · passenger car · Bar

245/45R17 tyre pressure in bar

Size
245/45R17
Class
passenger car
Planning PSI
36
Planning bar
2.48

bar

2.48

36 psi · 248 kPa · not a second factory sticker

245/45R17 · 36 psi · 2.48 bar · 248 kPa — estimates. Placard wins.

A 245/45R17 C-type or LT carcass can live far above a hatchback bar figure. This page’s 2.48 bar sketch is for the passenger car class, not every car that can physically mount the tyre. Under-inflation cooks the shoulders of a 245/45R17; over-inflation wears the centre rib and bangs every cat’s eye. 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

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

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 245/45R17 pressure by load

These 245/45R17 load steps are ± a few PSI from 36. They are not a licence to ignore a printed second column on a van or estate.

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 245/45R17 run 36 psi”, ignore it. A Qashqai and a Golf can share a size and not share a sticker.

What 245/45R17 means

Read 245/45R17 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.

Wide touring 17-inch. Rim diameter 17 in; section 245 mm. Estimates on this page assume a typical load index for the passenger car class.

Cars often seen on 245/45R17

These catalogue models are often seen on 245/45R17 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.

How to set 245/45R17

  1. Measure before the school run, not after the motorway.
  2. Write LF / RF / RR / RL. Do not keep 245/45R17 numbers in your head.
  3. Add air in short bursts toward the placard, using 36 psi only as a map.
  4. If one 245/45R17 is 4 psi down, hunt for a nail before you blame the weather.
  5. Log date, ambient temperature and the four readings.

Temperature drift

Roughly 1 psi per 5–6 °C. The table uses 36 psi as a 20 °C baseline for 245/45R17.

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 245/45R17
38 °C (heatwave tarmac)39 psi2.69 bar269 kPaDo not bleed a hot 245/45R17

If the door sticker and this 245/45R17 page disagree, the sticker wins.

Questions about 245/45R17

Can I run 245/45R17 at a lower pressure for comfort?

Not as a habit. A soft 245/45R17 cooks the shoulders and dulls steering. Keep load index and stay on the placard.

Is 245/45R17 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.

What is 245/45R17 in kPa?

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

What PSI should 245/45R17 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 245/45R17 and not share a sticker.

Is the sidewall number correct for 245/45R17?

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

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