GEM · e4 · Overview
Tyre pressure chart for the GEM e4
- 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
On a GEM e4 the useful pair is 34 psi (2.31 bar) up front and 34 psi (2.31 bar) at the back, mid-range. Under-inflation cooks the shoulders of a e4; over-inflation wears the centre rib and bangs every cat’s eye.
How to set the e4
- Park the GEM e4 for at least three hours (cold tyres).
- Use a calibrated gauge, not the only meter on a forecourt hose.
- Set the placard for that axle — about 32-35 psi / 2.2-2.4 bar front and 32-35 psi / 2.2-2.4 bar rear on this catalogue row.
- Recheck all four. A 2 psi miss on a front-wheel drive e4 is enough to feel a pull.
- Refit valve caps and reset TPMS if the handbook asks for a relearn.
Temperature and a cold gauge
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this e4.
| 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 |
Spare and inflator kit
A matching full-size spare on the GEM e4 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.
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 | 37 psi / 2.55 bar |
GEM e4 placard versus sidewall
If the GEM sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.
Estimated pressure by tyre size (225/50R17 and others)
Planning cold pressures for sizes often seen on a passenger car. This e4 sample opens with 225/50R17, then 185/65R15 and 225/45R17.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 225/50R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Touring 17-inch |
| 185/65R15 | 33 | 33 | 2.28 | 2.28 | 228 | 228 | Small / older car |
| 225/45R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Sport 17-inch |
| 215/55R16 | 34 | 35 | 2.34 | 2.41 | 234 | 241 | Slightly wider 16-inch |
| 245/40R18 | 36 | 36 | 2.48 | 2.48 | 248 | 248 | Wide touring 18-inch |
| 195/65R15 | 34 | 34 | 2.34 | 2.34 | 234 | 234 | Very common compact |
| 215/50R17 | 35 | 35 | 2.41 | 2.41 | 241 | 241 | Plus-size 17-inch |
| 205/60R16 | 34 | 34 | 2.34 | 2.34 | 234 | 234 | Taller 16-inch |
PSI, bar and kPa
1 bar ≈ 14.5 psi; 1 psi ≈ 6.89 kPa. Mid-points on the e4: 34 psi = 2.31 bar = 231 kPa.
| 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 |
GEM notes
No special GEM exception: the e4 uses the door-pillar placard. Size estimates on this page only help if you have left the original load index behind.
If the GEM sticker and this page disagree, the sticker wins.
Other GEM models
Questions about this e4
When does TPMS warn on a GEM e4?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
What PSI if I plus-size toward 225/45R17?
Keep load index at or above OEM. Low-profile sizes usually stay at or slightly above the placard. Use 225/50R17, 185/65R15 and 225/45R17 as a planning band.
Is the sidewall number correct on a GEM e4?
No. Sidewall PSI is a maximum. The e4 placard is the operating target, near 32-35/32-35 psi.
What is that in bar and kPa for the e4?
Mid-points are about 2.31 bar (231 kPa) front and 2.31 bar (231 kPa) rear.
How often should I check a e4?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Handbook: placard · bar vs PSI · front vs rear · cold inflation