Ruf · RT 12S · Front

Ruf RT 12S front 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 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 RT 12S 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 RT 12S; over-inflation wears the centre rib and bangs every cat’s eye.

Ruf RT 12S placard versus sidewall

Sidewall PSI is a carcass maximum. Recommended operating pressure for this RT 12S is the pillar sticker, near 34/34 psi.

Estimated pressure by tyre size (185/65R15 and others)

Planning cold pressures for sizes often seen on a passenger car. This RT 12S sample opens with 185/65R15, then 195/65R15 and 205/55R16.

Tyre size	Front PSI	Rear PSI	Front bar	Rear bar	Front kPa	Rear kPa	Note
185/65R15	33	—	2.28	—	228	—	Small / older car
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
205/60R16	34	—	2.34	—	234	—	Taller 16-inch
225/40R18	36	—	2.48	—	248	—	Low-profile 18-inch
225/45R17	35	—	2.41	—	241	—	Sport 17-inch
215/55R16	34	—	2.34	—	234	—	Slightly wider 16-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	37 psi / 2.55 bar

Steering feel on the RT 12S lives on this axle. Do not drop front pressure to “soften” a plus-size 205/55R16; you will roll the sidewall in a roundabout.

How to set the RT 12S

Measure before the school run, not after the M25.
Write LF / RF / RR / RL. Do not keep RT 12S 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 Ruf RT 12S 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 RT 12S.

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

Ruf notes

No special Ruf exception: the RT 12S 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 Ruf RT 12S 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 RT 12S than nitrogen upsells.

Other Ruf models

RT 12R RGT Turbo Florio Dakara CTR BTR RGT-8 R Kompressor

Questions about this RT 12S

What is that in bar and kPa for the RT 12S?

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

Is the sidewall number correct on a Ruf RT 12S?

No. Sidewall PSI is a maximum. The RT 12S placard is the operating target, near 32-35/32-35 psi.

What PSI if I plus-size toward 205/55R16?

Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 185/65R15, 195/65R15 and 205/55R16 as a planning band.

Front versus rear on the Ruf RT 12S?

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 Ruf RT 12S 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