Ruf · SCR · PSI
Ruf SCR tyre PSI
- 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
PSI is the Imperial reading most UK motorists still see on garage hoses. For the Ruf SCR the catalogue row is 32-35 psi front and 32-35 psi rear. A 10 °C overnight drop takes roughly 1 psi (0.07 bar) off a closed Ruf tyre.
Ruf SCR placard versus sidewall
Sidewall PSI is a carcass maximum. Recommended operating pressure for this SCR is the pillar sticker, near 34/34 psi.
PSI, bar and kPa
PSI-led conversions for the Ruf SCR 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 |
Estimated pressure by tyre size (215/50R17 and others)
215/50R17 is the first planning size here. 185/65R15 is usually the plus-size or LT step. Keep load index at or above original equipment.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 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 |
| 185/65R15 | 33 | 33 | 2.28 | 2.28 | 228 | 228 | Small / older car |
| 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 |
| 205/60R16 | 34 | 34 | 2.34 | 2.34 | 234 | 234 | Taller 16-inch |
| 225/40R18 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Low-profile 18-inch |
| 225/50R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Touring 17-inch |
How to set the SCR
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep SCR 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.
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 | 36 psi / 2.48 bar |
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this SCR.
| 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 SCR 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 SCR 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 Ruf sticker and this page disagree, the sticker wins.
Other Ruf models
Questions about this SCR
What is that in bar and kPa for the SCR?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
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.
How often should I check a SCR?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
When does TPMS warn on a Ruf SCR?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
What tyre pressure should a Ruf SCR 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