Melex · 423 · Rear
Melex 423 rear tyre pressure
- Drivetrain
- front-wheel drive
- Body
- passenger car
- PSI F / R
- 32-35 / 32-35
- Bar F / R
- 2.2-2.4 / 2.2-2.4
psi rear
34
2.31 bar · 231 kPa at the rear axle
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
Loaded 423 rears often need the sticker’s second column, not a copy of the front 32-35 psi figure. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed Melex tyre.
Melex 423 placard versus sidewall
Sidewall PSI is a carcass maximum. Recommended operating pressure for this 423 is the pillar sticker, near 34/34 psi.
Estimated pressure by tyre size (225/50R17 and others)
Planning cold pressures for sizes often seen on a passenger car. This 423 sample opens with 225/50R17, then 185/65R15 and 195/65R15.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 225/50R17 | — | 35 | — | 2.41 | — | 241 | Touring 17-inch |
| 185/65R15 | — | 33 | — | 2.28 | — | 228 | Small / older car |
| 195/65R15 | — | 34 | — | 2.34 | — | 234 | Very common compact |
| 215/50R17 | — | 35 | — | 2.41 | — | 241 | Plus-size 17-inch |
| 245/40R18 | — | 36 | — | 2.48 | — | 248 | Wide touring 18-inch |
| 215/55R16 | — | 35 | — | 2.41 | — | 241 | Slightly wider 16-inch |
| 225/45R17 | — | 35 | — | 2.41 | — | 241 | Sport 17-inch |
| 205/60R16 | — | 34 | — | 2.34 | — | 234 | Taller 16-inch |
Pressure against load
Load moves the rear of a passenger car 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 |
A family passenger car with a boot full of luggage should use the laden rear figure if Ford, VW or Mercedes printed one. Otherwise the modest steps in the load table are only a sketch for this 423.
How to set the 423
- Park the Melex 423 for at least three hours (cold tyres).
- Use a calibrated gauge, not the only meter on a forecourt hose.
- Set the placard for that axle — about 32-35 psi / 2.2-2.4 bar front and 32-35 psi / 2.2-2.4 bar rear on this catalogue row.
- Recheck all four. A 2 psi miss on a front-wheel drive 423 is enough to feel a pull.
- Refit valve caps and reset TPMS if the handbook asks for a relearn.
PSI, bar and kPa
PSI-led conversions for the Melex 423 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 |
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this 423.
| 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 |
Melex notes
No special Melex exception: the 423 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 Melex 423 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 423 than nitrogen upsells.
Other Melex models
Questions about this 423
When does TPMS warn on a Melex 423?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
What is that in bar and kPa for the 423?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
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.
Front versus rear on the Melex 423?
This row is 32-35 F / 32-35 R. Even when they match, a laden rear can justify a higher number if the sticker prints one.
How often should I check a 423?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Handbook: placard · bar vs PSI · front vs rear · cold inflation