Caterham · R300 Superlight · Recommended

Recommended tyre pressure for a Caterham R300 Superlight

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

34 / 34

Catalogue mid-points, front / rear · 2.2-2.4 / 2.2-2.4 bar

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

Treat this page as a map of the R300 Superlight band. The legal setpoint is the printed door-pillar label for your VIN. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed Caterham tyre.

How to set the R300 Superlight

Measure before the school run, not after the M25.
Write LF / RF / RR / RL. Do not keep R300 Superlight 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.

Caterham R300 Superlight placard versus sidewall

If the Caterham sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.

Estimated pressure by tyre size (195/65R15 and others)

Planning cold pressures for sizes often seen on a passenger car. This R300 Superlight sample opens with 195/65R15, then 215/50R17 and 225/45R17.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
195/65R15	34	34	2.34	2.34	234	234	Very common compact
215/50R17	35	35	2.41	2.41	241	241	Plus-size 17-inch
225/45R17	35	35	2.41	2.41	241	241	Sport 17-inch
245/40R18	36	36	2.48	2.48	248	248	Wide touring 18-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
225/40R18	36	36	2.48	2.48	248	248	Low-profile 18-inch
205/55R16	34	34	2.34	2.34	234	234	Typical mid-compact OEM

PSI, bar and kPa

PSI-led conversions for the Caterham R300 Superlight 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

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	38 psi / 2.62 bar

Temperature drift

Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this R300 Superlight.

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 R300 Superlight 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 R300 Superlight 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 R300 Superlight than nitrogen upsells.

Other Caterham models

Seven 485 21 Superlight Seven SV Classic S7 R 400 Cosworth CSR 200 Seven 620

Questions about this R300 Superlight

What is that in bar and kPa for the R300 Superlight?

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

When does TPMS warn on a Caterham R300 Superlight?

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 R300 Superlight?

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 tyre pressure should a Caterham R300 Superlight 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.

Is the sidewall number correct on a Caterham R300 Superlight?

No. Sidewall PSI is a maximum. The R300 Superlight placard is the operating target, near 32-35/32-35 psi.

Handbook: placard · bar vs PSI · front vs rear · cold inflation