Dutton · Sierra Drop Head · Cold
Setting cold tyres on a Dutton Sierra Drop Head
- Drivetrain
- rear-wheel drive
- Body
- pickup / double-cab
- 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
Cold means the Dutton Sierra Drop Head has stood at least three hours, or covered less than about a mile. Heat from a dual carriageway run is not the number you set. TPMS typically warns near 25 psi (about 25% below target). That is already a soft tyre, not a fill target. Commercial and load-biased bodies like this pickup / double-cab often need a higher rear; LT or C-type sizes such as LT245/75R16 are not filled like a Fiesta.
Temperature and a cold gauge
Roughly 1 psi per 5–6 °C. The table uses 34 psi as a 20 °C baseline for this Sierra Drop Head.
| 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 |
How to set the Sierra Drop Head
- Measure before the school run, not after the M25.
- Write LF / RF / RR / RL. Do not keep Sierra Drop Head 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.
Dutton Sierra Drop Head placard versus sidewall
If the Dutton sticker is painted over, the handbook is next. This website is a map, not a replacement VIN label.
Estimated pressure by tyre size (285/70R17 and others)
285/70R17 is the first planning size here. LT245/75R16 is usually the plus-size or LT step. Keep load index at or above original equipment.
| Tyre size | Front PSI | Rear PSI | Front bar | Rear bar | Front kPa | Rear kPa | Note |
|---|---|---|---|---|---|---|---|
| 285/70R17 | 38 | 41 | 2.62 | 2.83 | 262 | 283 | Wide all-terrain |
| 265/70R17 | 37 | 39 | 2.55 | 2.69 | 255 | 269 | Typical 17-inch load tyre |
| LT245/75R16 | 42 | 46 | 2.9 | 3.17 | 290 | 317 | LT-metric, higher load |
| 275/65R18 | 37 | 40 | 2.55 | 2.76 | 255 | 276 | Plus-size 18-inch |
| 235/75R15 | 35 | 37 | 2.41 | 2.55 | 241 | 255 | Older compact truck |
| LT265/70R17 | 42 | 48 | 2.9 | 3.31 | 290 | 331 | LT 17-inch |
| 255/65R17 | 37 | 39 | 2.55 | 2.69 | 255 | 269 | Highway 17-inch |
| 245/70R16 | 36 | 38 | 2.48 | 2.62 | 248 | 262 | Common 16-inch all-terrain |
PSI, bar and kPa
PSI-led conversions for the Dutton Sierra Drop Head 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 |
Load notes
Load moves the rear of a pickup / double-cab 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 |
| Payload / towing | 35 psi / 2.41 bar | 38 psi / 2.62 bar |
Dutton notes
No special Dutton exception: the Sierra Drop Head 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 Dutton Sierra Drop Head 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.
Keep the Dutton Sierra Drop Head on the printed band; use 285/70R17 and LT245/75R16 only as a map for non-OEM wheels.
Other Dutton models
Questions about this Sierra Drop Head
When does TPMS warn on a Dutton Sierra Drop Head?
Direct TPMS typically flags about 25% below placard — near 25 psi on this row. Fill to the sticker, not to the lamp.
What tyre pressure should a Dutton Sierra Drop Head 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.
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.
How often should I check a Sierra Drop Head?
Monthly, before a long trip, and after a 10 °C weather swing. Include a full-size spare.
Front versus rear on the Dutton Sierra Drop Head?
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.
Handbook: placard · bar vs PSI · front vs rear · cold inflation