Melex · 861 · Rear
Rear axle PSI and bar on the Melex 861
- 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 861 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 861 placard versus sidewall
Sidewall PSI is a carcass maximum. Recommended operating pressure for this 861 is the pillar sticker, near 34/34 psi.
Estimated pressure by tyre size (185/65R15 and others)
185/65R15 is the first planning size here. 225/40R18 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 |
|---|---|---|---|---|---|---|---|
| 185/65R15 | — | 33 | — | 2.28 | — | 228 | Small / older car |
| 205/55R16 | — | 34 | — | 2.34 | — | 234 | Typical mid-compact OEM |
| 225/40R18 | — | 36 | — | 2.48 | — | 248 | Low-profile 18-inch |
| 245/40R18 | — | 36 | — | 2.48 | — | 248 | Wide touring 18-inch |
| 225/50R17 | — | 35 | — | 2.41 | — | 241 | Touring 17-inch |
| 205/60R16 | — | 34 | — | 2.34 | — | 234 | Taller 16-inch |
| 215/55R16 | — | 35 | — | 2.41 | — | 241 | Slightly wider 16-inch |
| 195/65R15 | — | 34 | — | 2.34 | — | 234 | Very common compact |
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 | 37 psi / 2.55 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 861.
How to set the 861
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep 861 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.
PSI, bar and kPa
PSI-led conversions for the Melex 861 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 861.
| 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 861 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 861 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.
If the Melex sticker and this page disagree, the sticker wins.
Other Melex models
Questions about this 861
Front versus rear on the Melex 861?
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.
What PSI if I plus-size toward 225/40R18?
Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 185/65R15, 205/55R16 and 225/40R18 as a planning band.
What tyre pressure should a Melex 861 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.
How often should I check a 861?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Is the sidewall number correct on a Melex 861?
No. Sidewall PSI is a maximum. The 861 placard is the operating target, near 32-35/32-35 psi.
Handbook: placard · bar vs PSI · front vs rear · cold inflation