Caterham · Seven S3 · Bar

Caterham Seven S3 tyre pressure in bar

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

bar

2.31 / 2.31

32-35 / 32-35 psi · 231 / 231 kPa

32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa

2.3 bar is not 23 psi. On this Seven S3 2.2-2.4 bar converts to about 32-35 psi. Use the table, not a guess. Under-inflation cooks the shoulders of a Seven S3; over-inflation wears the centre rib and bangs every cat’s eye.

Bar, PSI and kPa

Bar-led conversions around the Caterham Seven S3. 2.2-2.4 bar is not “32-35 divided by ten”.

Bar	PSI	kPa
2.07	30	207
2.21	32	221
2.28	33	228
2.31	33.5	231
2.41	35	241
2.48	36	248
2.62	38	262
2.76	40	276
3.03	44	303
3.45	50	345
4.14	60	414

Caterham Seven S3 placard versus sidewall

Sidewall PSI is a carcass maximum. Recommended operating pressure for this Seven S3 is the pillar sticker, near 34/34 psi.

Estimated pressure by tyre size (225/45R17 and others)

Planning cold pressures for sizes often seen on a passenger car. This Seven S3 sample opens with 225/45R17, then 215/50R17 and 205/60R16.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
225/45R17	35	35	2.41	2.41	241	241	Sport 17-inch
215/50R17	35	35	2.41	2.41	241	241	Plus-size 17-inch
205/60R16	34	34	2.34	2.34	234	234	Taller 16-inch
185/65R15	33	33	2.28	2.28	228	228	Small / older car
195/65R15	34	34	2.34	2.34	234	234	Very common compact
225/50R17	35	35	2.41	2.41	241	241	Touring 17-inch
205/55R16	34	34	2.34	2.34	234	234	Typical mid-compact OEM
215/55R16	34	35	2.34	2.41	234	241	Slightly wider 16-inch

Load notes

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	38 psi / 2.62 bar

How to set the Seven S3

Park the Caterham Seven S3 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 Seven S3 is enough to feel a pull.
Refit valve caps and reset TPMS if the handbook asks for a relearn.

Temperature drift

Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this Seven S3.

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

Caterham notes

No special Caterham exception: the Seven S3 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 Caterham Seven S3 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 Seven S3 than nitrogen upsells.

Other Caterham models

21 Seven 360 Seven 620 Seven 485 Seven 310 Cosworth CSR 200 R300 Superlight Super 7

Questions about this Seven S3

What is that in bar and kPa for the Seven S3?

Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.

When does TPMS warn on a Caterham Seven S3?

Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.

Front versus rear on the Caterham Seven S3?

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 Seven S3?

Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.

What tyre pressure should a Caterham Seven S3 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