Alpina · Roadster Limited Edition · Front
Front axle PSI and bar on the Alpina Roadster Limited Edition
- Drivetrain
- rear-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
34
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
The front axle of a Alpina Roadster Limited Edition steers and, on rear-wheel drive cars, often pulls as well. Catalogue front pressure is 32-35 psi / 2.2-2.4 bar. TPMS typically warns near 25 psi (about 25% below target). That is already a soft tyre, not a fill target.
Alpina Roadster Limited Edition placard versus sidewall
The tyre-information placard on a Alpina Roadster Limited Edition sits on the driver’s door pillar (sometimes the fuel-filler flap). Catalogue figures here are a general band: 32-35 / 32-35 psi.
Estimated pressure by tyre size (195/65R15 and others)
Planning cold pressures for sizes often seen on a passenger car. This Roadster Limited Edition sample opens with 195/65R15, then 245/40R18 and 225/50R17.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 195/65R15 | 34 | — | 2.34 | — | 234 | — | Very common compact |
| 245/40R18 | 36 | — | 2.48 | — | 248 | — | Wide touring 18-inch |
| 225/50R17 | 35 | — | 2.41 | — | 241 | — | Touring 17-inch |
| 205/60R16 | 34 | — | 2.34 | — | 234 | — | Taller 16-inch |
| 225/45R17 | 35 | — | 2.41 | — | 241 | — | Sport 17-inch |
| 215/55R16 | 34 | — | 2.34 | — | 234 | — | Slightly wider 16-inch |
| 215/50R17 | 35 | — | 2.41 | — | 241 | — | Plus-size 17-inch |
| 185/65R15 | 33 | — | 2.28 | — | 228 | — | Small / older car |
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 Roadster Limited Edition lives on this axle. Do not drop front pressure to “soften” a plus-size 225/50R17; you will roll the sidewall in a roundabout.
How to set the Roadster Limited Edition
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep Roadster Limited Edition 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 Alpina Roadster Limited Edition 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 Roadster Limited Edition.
| 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 |
Alpina notes
No special Alpina exception: the Roadster Limited Edition 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 Alpina Roadster Limited Edition 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 Alpina sticker and this page disagree, the sticker wins.
Other Alpina models
Questions about this Roadster Limited Edition
Front versus rear on the Alpina Roadster Limited Edition?
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 Roadster Limited Edition?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
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.
What PSI if I plus-size toward 225/50R17?
Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 195/65R15, 245/40R18 and 225/50R17 as a planning band.
What is that in bar and kPa for the Roadster Limited Edition?
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