Lexus · RX 400 · kPa
Lexus RX 400 tyre pressure in kPa
- Drivetrain
- all-wheel drive
- Body
- SUV / crossover
- PSI F / R
- 32-35 / 32-35
- Bar F / R
- 2.2-2.4 / 2.2-2.4
kPa
231 / 231
2.31 / 2.31 bar · 32-35 / 32-35 psi
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
Kilopascals show up on some Asian stickers and ISO sheets. 231 kPa front and 231 kPa rear is the Lexus RX 400 midpoint (100 kPa = 1 bar). TPMS typically warns near 25 psi (about 25% below target). That is already a soft tyre, not a fill target. Keep side-to-side spread inside about 2 psi so the all-wheel drive hardware is not working on a radius mismatch.
kPa, bar and PSI
kPa-led conversions. 220 kPa is 2.2 bar and about 32 psi — handy if this RX 400 sticker uses SI units.
| kPa | Bar | PSI |
|---|---|---|
| 207 | 2.07 | 30 |
| 221 | 2.21 | 32 |
| 228 | 2.28 | 33 |
| 231 | 2.31 | 33.5 |
| 241 | 2.41 | 35 |
| 248 | 2.48 | 36 |
| 262 | 2.62 | 38 |
| 276 | 2.76 | 40 |
| 303 | 3.03 | 44 |
| 345 | 3.45 | 50 |
| 414 | 4.14 | 60 |
Estimated pressure by tyre size (245/60R18 and others)
245/60R18 is the first planning size here. 215/70R16 is usually the plus-size or LT step. Keep load index at or above original equipment.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 245/60R18 | 36 | 37 | 2.48 | 2.55 | 248 | 255 | Heavier CUV |
| 245/55R19 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Low-profile 19-inch |
| 215/70R16 | 34 | 34 | 2.34 | 2.34 | 234 | 234 | Compact crossover |
| 225/60R18 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Highway CUV |
| 235/65R17 | 35 | 36 | 2.41 | 2.48 | 241 | 248 | Mid-size SUV |
| 255/50R20 | 37 | 37 | 2.55 | 2.55 | 255 | 255 | 20-inch plus-size |
| 235/60R18 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Plus-size 18-inch |
| 225/65R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Very common 17-inch |
Lexus RX 400 placard versus sidewall
Sidewall PSI is a carcass maximum. Recommended operating pressure for this RX 400 is the pillar sticker, near 34/34 psi.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this RX 400.
| Ambient | Gauge (front mid) | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 31 psi | 2.14 bar | 214 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 32 psi | 2.21 bar | 221 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 33 psi | 2.28 bar | 228 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 34 psi | 2.34 bar | 234 kPa | Baseline |
| 30 °C | 36 psi | 2.48 bar | 248 kPa | Do not bleed a hot tyre |
| 38 °C (heatwave tarmac) | 37 psi | 2.55 bar | 255 kPa | Do not bleed a hot tyre |
How to set the RX 400
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep RX 400 numbers in your head.
- Add air in short bursts toward 34 psi (2.31 bar) front and 34 psi rear.
- If one corner is 4 psi down, hunt for a nail before you blame the weather.
- Log date, ambient temperature and the four readings.
Load notes
Load moves the rear of a SUV / crossover first. If the factory placard already has a “laden” column, use that instead of these sketches.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only | 34 psi / 2.34 bar | 34 psi / 2.34 bar |
| Full occupancy | 35 psi / 2.41 bar | 36 psi / 2.48 bar |
| Motorway + luggage | 36 psi / 2.48 bar | 38 psi / 2.62 bar |
Lexus notes
No special Lexus exception: the RX 400 uses the door-pillar placard. Size estimates on this page only help if you have left the original load index behind.
Spare and inflator kit
A matching full-size spare on the Lexus RX 400 usually follows the higher axle (often the rear, near 32-35 psi). A space-saver is commonly 60 psi / 4.1 bar — read that tyre’s own sidewall. An inflator kit is not a spare; check the sealant date.
A cheap gauge and a monthly habit will do more for this RX 400 than nitrogen upsells.
Other Lexus models
Questions about this RX 400
What is that in bar and kPa for the RX 400?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
How often should I check a RX 400?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Is the sidewall number correct on a Lexus RX 400?
No. Sidewall PSI is a maximum. The RX 400 placard is the operating target, near 32-35/32-35 psi.
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.
What tyre pressure should a Lexus RX 400 use?
Catalogue reference is 32-35 psi front and 32-35 psi rear (2.2-2.4 / 2.2-2.4 bar), cold. Confirm on the door-pillar placard.
Handbook: placard · bar vs PSI · front vs rear · cold inflation