UK · EU reference Tyre Pressure

235/50R18 · SUV / crossover · kPa

241 kPa for 235/50R18 tyres

Size
235/50R18
Class
SUV / crossover
Planning PSI
35
Planning bar
2.41

kPa

241

2.41 bar · 35 psi · 100 kPa = 1 bar

235/50R18 · 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 235/50R18 (2.41 bar / 35 psi). 100 kPa = 1 bar. 18-inch CUV. These rows are estimates interpolated for the size, not OEM for a named VIN.

kPa, bar and PSI

Convert around the 235/50R18 band. 2.41 bar is about 35 psi — not 23, not 33 unless the maths says so.

kPaBarPSI
2142.1431
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

Estimated 235/50R18 pressure by load

These 235/50R18 load steps are ± a few PSI from 35. They are not a licence to ignore a printed second column on a van or estate.

ConditionFront (est.)Rear (est.)
Driver only / unladen35 psi / 2.41 bar / 241 kPa37 psi / 2.55 bar / 255 kPa
Typical occupancy35 psi / 2.41 bar / 241 kPa38 psi / 2.62 bar / 262 kPa
Motorway + luggage (sketch)36 psi / 2.48 bar / 248 kPa39 psi / 2.69 bar / 269 kPa

What 235/50R18 means

235/50R18 means a 235 millimetre section width, a sidewall that is 50 percent of that width, on a 18-inch rim. The R is radial construction.

18-inch CUV. Rim diameter 18 in; section 235 mm. Estimates on this page assume a typical load index for the SUV / crossover class.

Placard versus sidewall

If a forum says “all 235/50R18 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 235/50R18.

AmbientGaugeBarkPaNote
−5 °C (hard frost)32 psi2.21 bar221 kPaGauge reads low; do not overfill once warm
0 °C33 psi2.28 bar228 kPaGauge reads low; do not overfill once warm
8 °C (UK winter morning)34 psi2.34 bar234 kPaGauge reads low; do not overfill once warm
20 °C (set cold here)35 psi2.41 bar241 kPaBaseline for this size sketch
30 °C37 psi2.55 bar255 kPaDo not bleed a hot 235/50R18
38 °C (heatwave tarmac)38 psi2.62 bar262 kPaDo not bleed a hot 235/50R18

How to set 235/50R18

  1. Park so the 235/50R18 tyres are cold (three hours, or less than about a mile).
  2. Read the door-pillar placard for that car — not the 235/50R18 sidewall maximum.
  3. If the sticker is missing, 35 psi / 2.41 bar is only a SUV / crossover 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 235/50R18

These catalogue models are often seen on 235/50R18 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.

If the door sticker and this 235/50R18 page disagree, the sticker wins.

Questions about 235/50R18

What is 235/50R18 in bar?

35 psi is 2.41 bar. Add a tenth of a bar if the placard’s laden column is higher, which is common on vans that wear this size.

What is 235/50R18 in kPa?

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

Is 235/50R18 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.

When does TPMS warn on 235/50R18?

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.

What PSI should 235/50R18 tyres be?

A SUV / crossover planning figure is about 35 psi cold (2.41 bar / 241 kPa). Confirm on the vehicle placard — two cars can share 235/50R18 and not share a sticker.

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