275/70R18 · pickup / double-cab · Overview
Recommended pressure for 275/70R18 tyres
- Size
- 275/70R18
- Class
- pickup / double-cab
- Planning PSI
- 37
- Planning bar
- 2.55
275/70R18
37 psi / 2.55 bar
255 kPa · estimates for this size class
275/70R18 · 37 psi · 2.55 bar · 255 kPa — estimates. Placard wins.
Searches for “275/70R18 pressure” usually want a number. Use 37 psi (2.55 bar) only as a sketch; the door-pillar placard on the car that wears this size still wins. Under-inflation cooks the shoulders of a 275/70R18; over-inflation wears the centre rib and bangs every cat’s eye.
What 275/70R18 means
Read 275/70R18 as width / aspect R rim. Nothing in the size string is a pressure. Pressure lives on the car, not moulded as 205 or 55.
Heavier rear-bias 18-inch truck. Rim diameter 18 in; section 275 mm. Estimates on this page assume a typical load index for the pickup / double-cab class.
Estimated 275/70R18 pressure by load
Plus-sizing to 275/70R18 from a taller OEM tyre usually keeps the same placard if the load index is equal or higher.
| Condition | Front (est.) | Rear (est.) |
|---|---|---|
| Driver only / unladen | 37 psi / 2.55 bar / 255 kPa | 39 psi / 2.69 bar / 269 kPa |
| Typical occupancy | 38 psi / 2.62 bar / 262 kPa | 41 psi / 2.83 bar / 283 kPa |
| Payload / towing (sketch) | 39 psi / 2.69 bar / 269 kPa | 42 psi / 2.9 bar / 290 kPa |
PSI, bar and kPa
1 bar ≈ 14.5 psi; 1 psi ≈ 6.89 kPa. Planning midpoint for 275/70R18: 37 psi = 2.55 bar = 255 kPa.
| PSI | Bar | kPa |
|---|---|---|
| 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 |
| 48 | 3.31 | 331 |
| 49 | 3.38 | 338 |
Placard versus sidewall
The sidewall of a 275/70R18 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 275/70R18
These catalogue models are often seen on 275/70R18 or a close OEM neighbour. Open the vehicle chart for axle-specific PSI and bar.
How to set 275/70R18
- Measure before the school run, not after the motorway.
- Write LF / RF / RR / RL. Do not keep 275/70R18 numbers in your head.
- Add air in short bursts toward the placard, using 37 psi only as a map.
- If one 275/70R18 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 37 psi as a 20 °C baseline for 275/70R18.
| Ambient | Gauge | Bar | kPa | Note |
|---|---|---|---|---|
| −5 °C (hard frost) | 34 psi | 2.34 bar | 234 kPa | Gauge reads low; do not overfill once warm |
| 0 °C | 35 psi | 2.41 bar | 241 kPa | Gauge reads low; do not overfill once warm |
| 8 °C (UK winter morning) | 36 psi | 2.48 bar | 248 kPa | Gauge reads low; do not overfill once warm |
| 20 °C (set cold here) | 37 psi | 2.55 bar | 255 kPa | Baseline for this size sketch |
| 30 °C | 39 psi | 2.69 bar | 269 kPa | Do not bleed a hot 275/70R18 |
| 38 °C (heatwave tarmac) | 40 psi | 2.76 bar | 276 kPa | Do not bleed a hot 275/70R18 |
If the door sticker and this 275/70R18 page disagree, the sticker wins.
Questions about 275/70R18
Is 275/70R18 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 PSI should 275/70R18 tyres be?
A pickup / double-cab planning figure is about 37 psi cold (2.55 bar / 255 kPa). Confirm on the vehicle placard — two cars can share 275/70R18 and not share a sticker.
When does TPMS warn on 275/70R18?
Direct TPMS typically flags about 25% below target — near 28 psi if you were aiming at 37. Fill to the sticker, not to the lamp.
What is 275/70R18 in bar?
37 psi is 2.55 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 275/70R18 at a lower pressure for comfort?
Not as a habit. A soft 275/70R18 cooks the shoulders and dulls steering. Keep load index and stay on the placard.
Handbook: placard · bar vs PSI · cold inflation · all sizes