Caterham · R300 Superlight · Front

Front axle PSI and bar on the 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 front

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 R300 Superlight 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 R300 Superlight; over-inflation wears the centre rib and bangs every cat’s eye.

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 (225/45R17 and others)

Planning cold pressures for sizes often seen on a passenger car. This R300 Superlight sample opens with 225/45R17, then 205/60R16 and 195/65R15.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
225/45R17	35	—	2.41	—	241	—	Sport 17-inch
205/60R16	34	—	2.34	—	234	—	Taller 16-inch
195/65R15	34	—	2.34	—	234	—	Very common compact
205/55R16	34	—	2.34	—	234	—	Typical mid-compact OEM
215/50R17	35	—	2.41	—	241	—	Plus-size 17-inch
215/55R16	34	—	2.34	—	234	—	Slightly wider 16-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	35 psi / 2.41 bar	36 psi / 2.48 bar
Motorway + luggage	36 psi / 2.48 bar	36 psi / 2.48 bar

Steering feel on the R300 Superlight lives on this axle. Do not drop front pressure to “soften” a plus-size 195/65R15; you will roll the sidewall in a roundabout.

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.

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

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.

If the Caterham sticker and this page disagree, the sticker wins.

Other Caterham models

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

Questions about this R300 Superlight

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.

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.

What PSI if I plus-size toward 195/65R15?

Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 225/45R17, 205/60R16 and 195/65R15 as a planning band.

How often should I check a R300 Superlight?

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

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.

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