Alfa Romeo · 166 · Bar
Alfa Romeo 166 bar chart (2.2-2.4 / 2.2-2.4)
- 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
bar
2.31 / 2.31
32-35 / 32-35 psi · 231 / 231 kPa
32-35 psi F · 32-35 psi R · 2.2-2.4 / 2.2-2.4 bar · 231/231 kPa
A front-wheel drive Alfa Romeo 166 still wants even corners. 2.2-2.4 vs 2.2-2.4 is an axle split, not a left-right split. Size estimates on this page include 195/65R15, 225/50R17 and 245/40R18 — interpolated from the catalogue midpoint, not a second factory sticker.
Bar, PSI and kPa
Bar-led conversions around the Alfa Romeo 166. 2.2-2.4 bar is not “32-35 divided by ten”.
| Bar | PSI | kPa |
|---|---|---|
| 2.07 | 30 | 207 |
| 2.21 | 32 | 221 |
| 2.28 | 33 | 228 |
| 2.31 | 33.5 | 231 |
| 2.41 | 35 | 241 |
| 2.48 | 36 | 248 |
| 2.62 | 38 | 262 |
| 2.76 | 40 | 276 |
| 3.03 | 44 | 303 |
| 3.45 | 50 | 345 |
| 4.14 | 60 | 414 |
Alfa Romeo 166 placard versus sidewall
If the Alfa Romeo 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)
If your Alfa Romeo 166 no longer wears the OEM diameter, start at the row nearest 195/65R15 or 225/50R17 and confirm with the tyre maker’s load table.
| 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 |
| 225/50R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Touring 17-inch |
| 245/40R18 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Wide touring 18-inch |
| 215/55R16 | 34 | 35 | 2.34 | 2.41 | 234 | 241 | Slightly wider 16-inch |
| 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 |
| 225/45R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Sport 17-inch |
| 215/50R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Plus-size 17-inch |
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 |
How to set the 166
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep 166 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.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this 166.
| 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 |
Alfa Romeo notes
No special Alfa Romeo exception: the 166 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 Alfa Romeo 166 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 Alfa Romeo sticker and this page disagree, the sticker wins.
Other Alfa Romeo models
Questions about this 166
What is that in bar and kPa for the 166?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
What tyre pressure should a Alfa Romeo 166 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.
How often should I check a 166?
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.
Is the sidewall number correct on a Alfa Romeo 166?
No. Sidewall PSI is a maximum. The 166 placard is the operating target, near 32-35/32-35 psi.
Handbook: placard · bar vs PSI · front vs rear · cold inflation