Oldtimer · De Dion Bouton · Front
Front axle PSI and bar on the Oldtimer De Dion Bouton
- 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 front
34
2.31 bar · 231 kPa at the steering axle
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
A 3 psi miss on one front corner of this De Dion Bouton shows up as a wander before the TPMS lamp bothers you. Target 34 psi (2.31 bar) cold. Under-inflation cooks the shoulders of a De Dion Bouton; over-inflation wears the centre rib and bangs every cat’s eye.
Oldtimer De Dion Bouton placard versus sidewall
If the Oldtimer sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.
Estimated pressure by tyre size (205/60R16 and others)
205/60R16 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 |
|---|---|---|---|---|---|---|---|
| 205/60R16 | 34 | — | 2.34 | — | 234 | — | Taller 16-inch |
| 195/65R15 | 34 | — | 2.34 | — | 234 | — | Very common compact |
| 225/40R18 | 36 | — | 2.48 | — | 248 | — | Low-profile 18-inch |
| 225/50R17 | 35 | — | 2.41 | — | 241 | — | Touring 17-inch |
| 225/45R17 | 35 | — | 2.41 | — | 241 | — | Sport 17-inch |
| 215/50R17 | 35 | — | 2.41 | — | 241 | — | Plus-size 17-inch |
| 185/65R15 | 33 | — | 2.28 | — | 228 | — | Small / older car |
| 245/40R18 | 36 | — | 2.48 | — | 248 | — | Wide touring 18-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 | 34 psi / 2.34 bar | 35 psi / 2.41 bar |
| Motorway + luggage | 35 psi / 2.41 bar | 36 psi / 2.48 bar |
Steering feel on the De Dion Bouton lives on this axle. Do not drop front pressure to “soften” a plus-size 225/40R18; you will roll the sidewall in a roundabout.
How to set the De Dion Bouton
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep De Dion Bouton 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 Oldtimer De Dion Bouton 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 De Dion Bouton.
| 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 |
Oldtimer notes
No special Oldtimer exception: the De Dion Bouton 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 Oldtimer De Dion Bouton 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.
Keep the Oldtimer De Dion Bouton on the printed band; use 205/60R16 and 225/40R18 only as a map for non-OEM wheels.
Other Oldtimer models
Questions about this De Dion Bouton
What is that in bar and kPa for the De Dion Bouton?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
What tyre pressure should a Oldtimer De Dion Bouton 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.
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.
How often should I check a De Dion Bouton?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Is the sidewall number correct on a Oldtimer De Dion Bouton?
No. Sidewall PSI is a maximum. The De Dion Bouton placard is the operating target, near 32-35/32-35 psi.
Handbook: placard · bar vs PSI · front vs rear · cold inflation