205/40R17 · passenger car · Overview
205/40R17: PSI, bar and kPa
- Size
- 205/40R17
- Class
- passenger car
- Planning PSI
- 35
- Planning bar
- 2.41
205/40R17
35 psi / 2.41 bar
241 kPa · estimates for this size class
205/40R17 · 35 psi · 2.41 bar · 241 kPa — estimates. Placard wins.
205/40R17 is a passenger car size (205 mm section, 40 % aspect, 17-inch rim). A planning cold figure around 35 psi / 2.41 bar / 241 kPa is a starting map, not a second factory sticker. Very low 17-inch compact. These rows are estimates interpolated for the size, not OEM for a named VIN. Low-profile {sz} does not want a “softer” pressure to recover ride. Stay at or slightly above the car’s original placard if load index is kept.
What 205/40R17 means
Read 205/40R17 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.
Very low 17-inch compact. Rim diameter 17 in; section 205 mm. Estimates on this page assume a typical load index for the passenger car class.
Estimated 205/40R17 pressure by load
These 205/40R17 load steps are ± a few PSI from 35. They are not a licence to ignore a printed second column on a van or estate.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 35 psi / 2.41 bar / 241 kPa | 35 psi / 2.41 bar / 241 kPa |
| Typical occupancy | 36 psi / 2.48 bar / 248 kPa | 37 psi / 2.55 bar / 255 kPa |
| Motorway + luggage (sketch) | 37 psi / 2.55 bar / 255 kPa | 38 psi / 2.62 bar / 262 kPa |
PSI, bar and kPa
1 bar ≈ 14.5 psi; 1 psi ≈ 6.89 kPa. Planning midpoint for 205/40R17: 35 psi = 2.41 bar = 241 kPa.
| PSI | Bar | kPa |
|---|---|---|
| 31 | 2.14 | 214 |
| 32 | 2.21 | 221 |
| 33 | 2.28 | 228 |
| 34 | 2.34 | 234 |
| 35 | 2.41 | 241 |
| 36 | 2.48 | 248 |
| 37 | 2.55 | 255 |
| 38 | 2.62 | 262 |
| 39 | 2.69 | 269 |
| 40 | 2.76 | 276 |
| 41 | 2.83 | 283 |
| 42 | 2.90 | 290 |
| 43 | 2.96 | 296 |
| 44 | 3.03 | 303 |
| 45 | 3.10 | 310 |
| 46 | 3.17 | 317 |
| 47 | 3.24 | 324 |
Placard versus sidewall
The sidewall of a 205/40R17 may say 51 psi or 350 kPa. That is a carcass maximum. Operating pressure is the tyre-information placard on the driver’s door pillar.
Cars often seen on 205/40R17
These catalogue models are often seen on 205/40R17 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.
How to set 205/40R17
- Park so the 205/40R17 tyres are cold (three hours, or less than about a mile).
- Read the door-pillar placard for that car — not the 205/40R17 sidewall maximum.
- If the sticker is missing, 35 psi / 2.41 bar is only a passenger car planning figure for this size.
- Set all four with a calibrated gauge. A 3 psi miss on one corner shows up as a wander.
- Refit valve caps and reset TPMS if the handbook asks for a relearn.
Temperature drift
Roughly 1 psi per 5–6 °C. The table uses 35 psi as a 20 °C baseline for 205/40R17.
| Ambient | Gauge | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 32 psi | 2.21 bar | 221 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 33 psi | 2.28 bar | 228 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 34 psi | 2.34 bar | 234 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 35 psi | 2.41 bar | 241 kPa | Baseline for this size sketch |
| 30 °C | 37 psi | 2.55 bar | 255 kPa | Do not bleed a hot 205/40R17 |
| 38 °C (heatwave tarmac) | 38 psi | 2.62 bar | 262 kPa | Do not bleed a hot 205/40R17 |
If the door sticker and this 205/40R17 page disagree, the sticker wins.
Questions about 205/40R17
Is the sidewall number correct for 205/40R17?
No. Sidewall PSI or kPa is a maximum for the carcass. Operating pressure is the door-pillar placard.
Is 205/40R17 the same as a plus-size swap?
Only if that is the size you fitted. Overall diameter should stay close to OEM. Pressure still follows the car, with load index at or above original.
What is 205/40R17 in bar?
35 psi is 2.41 bar. Add a tenth of a bar if the placard’s laden column is higher, which is common on vans that wear this size.
Can I run 205/40R17 at a lower pressure for comfort?
Not as a habit. A soft 205/40R17 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
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.
Handbook: placard · bar vs PSI · cold inflation · all sizes