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Recommended cold tyre pressure by vehicle type, load and season, with temperature drift and sidewall-limit checks.
This guide converts a vehicle class, load and ambient temperature into a recommended cold tyre inflation pressure in psi, bar and kPa. Cold means the tyre has been parked at least three hours or driven under about three kilometres — the state every placard and every tyre standard (ETRTO, TRA, JATMA) refers to. Temperature drift is computed from Gay-Lussac's law on absolute pressure, so you can see how far the gauge will fall on a cold morning and whether the load adders would breach the MAX PRESS figure moulded on your sidewall.
Open Tyre Pressure Guide on AltFTool — it loads instantly in your browser.
Add your input to the workspace.
Adjust the options until the result looks right.
Copy or download the output and put it to work.
Every figure is a cold inflation pressure in psi, bar and kPa, so it matches your placard and any workshop gauge.
Drift uses the absolute-pressure gas law rather than the rough 1 psi per 10 °F rule of thumb.
Enter the MAX PRESS figure and load adders are capped at it instead of pushing you past the tyre's rating.
The figure on your vehicle's placard — the sticker in the driver's door jamb, on the fuel flap or in the glovebox — is the only correct answer, and it is a cold pressure. Mainstream hatchbacks and sedans usually sit between 30 and 34 psi (about 2.1-2.3 bar), compact SUVs 31-35 psi, and loaded full-size SUVs and pickups run higher at the rear. The MAX PRESS number on the tyre sidewall is the tyre's structural ceiling, not a recommendation.
Always cold. A tyre warmed by normal driving reads roughly 4 psi above its cold value, so bleeding air out of a hot tyre to hit the placard number leaves you around 4 psi under-inflated once it cools. If you can only reach a pump after a drive, set it about 4 psi above the placard figure and re-check the next morning.
About 1 psi for every 10 °F (roughly 1.6-1.8 psi per 10 °C) drop in ambient temperature, because absolute pressure falls in proportion to absolute temperature. A tyre set to 33 psi on a 35 °C afternoon reads about 28 psi on a 5 °C morning — a real 14% under-inflation, not a faulty gauge.
Yes, and mostly at the rear. Manufacturer placards with a full-load column typically add 0.2-0.3 bar (about 3-4 psi) to the loaded axle, and many European manuals ask for a further 0.2 bar before sustained high-speed running. Follow your own placard's load column where one exists; this guide's adders are typical values, not a substitute for it.