Lexus · RX 400 · PSI
Lexus RX 400 inflation in PSI (32-35 front, 32-35 rear)
- 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
psi
34 / 34
Catalogue mid-points, front / rear · 2.2-2.4 / 2.2-2.4 bar
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
PSI is the Imperial reading most UK motorists still see on garage hoses. For the Lexus RX 400 the catalogue row is 32-35 psi front and 32-35 psi rear. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed Lexus tyre. Keep side-to-side spread inside about 2 psi so the all-wheel drive hardware is not working on a radius mismatch.
Lexus RX 400 placard versus sidewall
If the Lexus sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.
PSI, bar and kPa
PSI-led conversions for the Lexus RX 400 band (32-35 / 32-35).
| PSI | Bar | kPa |
|---|---|---|
| 30 | 2.07 | 207 |
| 32 | 2.21 | 221 |
| 33 | 2.28 | 228 |
| 33.5 | 2.31 | 231 |
| 35 | 2.41 | 241 |
| 36 | 2.48 | 248 |
| 38 | 2.62 | 262 |
| 40 | 2.76 | 276 |
| 44 | 3.03 | 303 |
| 50 | 3.45 | 345 |
| 60 | 4.14 | 414 |
Estimated pressure by tyre size (235/65R17 and others)
235/65R17 is the first planning size here. 255/50R20 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 |
|---|---|---|---|---|---|---|---|
| 235/65R17 | 35 | 36 | 2.41 | 2.48 | 241 | 248 | Mid-size SUV |
| 245/60R18 | 36 | 37 | 2.48 | 2.55 | 248 | 255 | Heavier CUV |
| 255/50R20 | 37 | 37 | 2.55 | 2.55 | 255 | 255 | 20-inch plus-size |
| 245/55R19 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Low-profile 19-inch |
| 225/60R18 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Highway CUV |
| 225/65R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Very common 17-inch |
| 235/60R18 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Plus-size 18-inch |
| 215/70R16 | 34 | 34 | 2.34 | 2.34 | 234 | 234 | Compact crossover |
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 | 36 psi / 2.48 bar |
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 |
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.
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.
What PSI if I plus-size toward 255/50R20?
Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 235/65R17, 245/60R18 and 255/50R20 as a planning band.
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.
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