Oldtimer · De Dion Bouton · Rear

Oldtimer De Dion Bouton 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

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 De Dion Bouton rears often need the sticker’s second column, not a copy of the front 32-35 psi figure. 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

Sidewall PSI is a carcass maximum. Recommended operating pressure for this De Dion Bouton is the pillar sticker, near 34/34 psi.

Estimated pressure by tyre size (205/60R16 and others)

Planning cold pressures for sizes often seen on a passenger car. This De Dion Bouton sample opens with 205/60R16, then 205/55R16 and 245/40R18.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
205/60R16	—	34	—	2.34	—	234	Taller 16-inch
205/55R16	—	34	—	2.34	—	234	Typical mid-compact OEM
245/40R18	—	36	—	2.48	—	248	Wide touring 18-inch
215/55R16	—	35	—	2.41	—	241	Slightly wider 16-inch
225/40R18	—	36	—	2.48	—	248	Low-profile 18-inch
185/65R15	—	33	—	2.28	—	228	Small / older car
225/45R17	—	35	—	2.41	—	241	Sport 17-inch
225/50R17	—	35	—	2.41	—	241	Touring 17-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

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 De Dion Bouton.

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.

A cheap gauge and a monthly habit will do more for this De Dion Bouton than nitrogen upsells.

Other Oldtimer models

Amphicar Audi Adler Alvis AC American Austin Avanti

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.

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.

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.

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